Biology exam – MU Sofia Exam preparation

Welcome to your Biology exam

1. Which of the following statements about the epithelial tissue is true?

A. is composed of elongated cells.

B. It contains a large amount of extracellular substance.

C. The cells have excitatory function.

D. It makes up the exocrine and endocrine glands.

2. Which of the following statements about the connective tissue is true?

A. It has a covering function.

B. It contains a small amount of extracellular substance.

C. The cells can produce collagen.

D. The cells are tightly packed.

3. Which of the following statements about the connective tissue is true?

A. The bone tissue provides thermal insulation.

B. The adipose tissue provides body support.

C. makes up the outer coverings of the nerves and blood vessels

D. Blood has a jelly-like extracellular substance

4. Which of the following statements about the muscle tissue is true?

A. It has a covering function.

B. It contains a large amount of extracellular substance.

C. The cells have excitatory function.

D. It makes up the capillaries.

5. Which of the following statements about the skeletal muscle tissue is true?

A. It is composed of muscle fibers.

B. The cells have up to two nuclei.

C. The cells have involuntary control.

D. The tissue makes up the blood vessel wall.

6. Which of the following statements about the smooth muscle tissue is true?

A. The cells have multiple nuclei.

B. The cells have a transverse striation.

C. The cells have voluntary control.

D. The tissue make up the blood vessel wall.

7. Which of the following statements about the cardiac muscle tissue is true?

A. The cells are flat.

B. The cells have a transverse striation.

C. All the cells have only one nucleus.

D. The tissue makes up the wall of hollow internal organs.

8. Which of the following statements about the nervous tissue is true?

A. It has a covering function.

B. Tissue cells produce collagen fibers.

C. It is made up of multinucleated cells.

D. One of the major cell types are glial cells.

9. Which of the following statements about the neuron is true?

A. It can have multiple nuclei.

B. It can produce collagen fibers.

C. It has the properties of excitability and conductivity.

D. It can form the myelin sheath.

10. Which of the following statements about glial cells is true?

A. They cannot divide.

B. They can destroy dead nerve cells.

C. They have the properties of excitability and contraction.

D. They show transverse striation.

11. Which of the following statements about the synapse is true?

A. It is formed between a muscle cell and a glandular cell.

B. It is formed between a nerve cell and a connective tissue cell.

C. It serves to transmit nerve impulses by releasing a mediator.

D. It is formed between glial cells.

12. Which of the following statements about bones is not true?

A. They consist of a dense and spongy bony substance.

B.The bones of adult individuals are more elastiAnswer,,C.

C. Bones are covered on the outside by periosteum.

D. Bones form cavities for the internal organs.

13. Which of the following statements about bones is true?

A. Limb bones are mostly flat.

B. Long bones are found in the spine.

C. part of the pelvic bones are flat bones.

D. The scapula is a short bone.

14. Which of the following statements about the skull is true?

A. The mandible belongs to the neurocranium.

B. The mandible articulates with the temporal bone.

C. The bones of the neurocranium are frontal, parietal, occipital and palatine.

D. The bones of the facial skull are maxilla, vomer, sphenoid.

15. What about the following statements about the spine is true?

A. consists of 8 cervical, 12 thoracic, 5 lumbar, a sacrum, and a coccyx.

B. The first cervical vertebra is connected to the sphenoid bone.

C. The cervical vertebrae are the largest.

D. The thoracic spine is the least mobile.

16. Which of the following statements about the limb skeleton is true?

A. The humerus is part of the shoulder girdle.

B. The clavicle is a flat bone.

C. The free lower limb consists of the pelvic bones, tibia, fibula, and the bones of the foot.

D. The foot skeleton is composed of 7 tarsals, 5 metatarsals, and 14phalanges.

17. Which of the following statements about the skeletal muscles is true?

A. The diaphragm separates the abdominal cavity from the pelvis.

B. The trapezius is a muscle of the abdominal wall.

C. The deltoid muscle is involved in the pelvic girdle movements.

D. The triceps brachii muscle extends the elbow joint.

18. The alimentary canal consists of the following sequential organs:

A. Oral cavity small intestine, stomach, large intestine.

B. Oral cavity, stomach, pharynx, oesophagus, small intestine, large intestine.

C. Oral cavity, pharynx, oesophagus, stomach, small intestine, large intestine.

D. Oral cavity, pharynx, small intestine, oesophagus, stomach, large intestine.

19. Which of the following statements about the oral cavity is true?

A. The permanent teeth consist of 8 incisors, 4 canines, 8 premolars, and 12 molars.

B. Taste receptors are concentrated on the inferior surface of the tongue.

C. The tongue is composed of smooth muscle tissue.

D. The major salivary glands are parotid, submandibular, and lacrimal.

20. Which of the following statements about the stomach is not true?

A. The musculature of the stomach performs peristaltic movements.

B. Gastric juice contains the enzyme trypsin and hydrochloric acid.

C. The gastric mucosa produces a protective mucus.

D. A round muscle, the sphincter, is located at the entrance and exit of the stomach.

21. Which of the following statements about the intestine is true?

A. The terminal part ofthe small intestine is called the duodenum.

B. Secretions of the liver and pancreas empty into the initial part of the large intestine.

C. The appendix is connected to the initial part of the large intestine.

D. The small intestine has a length of 1.5 m.

22. Which of the following statements about the liver and pancreas is true?

A. The pancreas secretes bile juice.

B. The liver is an exocrine and endocrine gland.

C. Pancreatic juice contains the enzymes pepsin, amylase and lipase.

D. Pancreatic juice neutralizes the hydrochloric acid entering from the stomach.

23. Which of the following statements about the upper respiratory tract is not true?

A. The external nose is formed by the maxillary and nasal bones.

B. Behind the nasal cavity is the upper pharynx.

C. The vocal cords are located in the broad upper part of the pharynx.

D. The larynx is located in front of the lowest part of the pharynx.

24. Which of the following statements about the lower respiratory tract is not true?

A. The trachea and bronchi are covered by ciliated epithelium.

B. The trachea is an extension of the pharynx.

C. The wall of the trachea and bronchi contains cartilaginous tissue.

D. The wall of the bronchioles contains smooth muscle tissue.

25. Which of the following statements about the lungs is true?

A. It is a non-paired organ.

B. It is covered on the outside by a thin membrane

C. The right lung is smaller than the left.

D. Gas exchange takes place across the wall of the alveoli.

26. Which of the following statements about the kidneys is true?

A. They are located in the lower part of the thoracic cavity.

B. They are 5 cm long and 2 cm wide.

C. The kidneys are poorly supplied with blood.

D. The main structural unit is the nephron.

27. Which of the following statements about the urinary tract is not true?

A. The ureters are 30 cm long and about 8 mm in diameter.

B. Urine moves down the ureters by peristaltic movements.

C. The bladder has smooth muscle in the wall.

D. The urethra connects the renal pelvis to the bladder.

28. Which of the following statements about the cardiovascular system is true?

A. The pulmonary circuit begins from the left ventricle.

B. The systemic circuit begins from the right ventricle.

C The pulmonary circuit ends with the pulmonary veins.

D. The systemic circuit ends with the pulmonary veins.

29. Which of the following statements about the heart is true?

A. The heart contraction is performed by the inner layer of the heart wall

B. It is cone-shaped, with its apex pointing downward, to the right, and forward.

C. Oxygenated blood flows through the left atrium and ventricle.

D. Specialized cells in the left atrium give rise to cardiac contraction.

30. Which of the following statements about the heart is not true?

A. It is encased by a double-layered sac

B. It consists of four chambers

C. Between the atria and ventricles there are semilunar valves.

D. The middle layer of the heart wall is called the myocardium.

31. Which of the following statements about the heart valves is not true?

A. Ventricular contraction opens the atrioventricular valves.

B. A semilunar valve is located at the origin of the pulmonary artery.

C. Ventricular contraction closes the atrioventricular valves.

D. The right atrioventricular valve is called the tricuspid valve.

32. Which of the following statements about blood vessels is true?

A. Capillaries are made of smooth muscle because of the high velocity of blood in them.

B. Veins carry blood out of the heart.

C. Arteries carry blood out of the heart.

D. Some small size arteries have pocket-like valves.

33. Which of the following statements about blood is not true?

A. Blood plasma makes up 55% of blood volume

B. Blood plasma contains up to 92% water and dissolved proteins, glucose , etc

C. The basic protein of blood clotting is called fibrinogen.

D. Blood serum coagulates because it contains fibrinogen.

34. Which of the following statements about the form elements of blood is true?

A. Erythrocytes have small nuclei and some basic organelles.

B. The normal count of leukocytes per $1mm^3$ of blood is 4000-10 000.

C. Leukocytes contain haemoglobin.

D. Platelets are small cells.

35. Which of the following statements about the immune system is not true?

A. Acquired immunity develops during postnatal development.

B. Viruses and bacteria can be antigens for the immune system.

C. Live vaccines contain bacteria or viruses irradiated with ultraviolet or gamma rays.

D. Autoimmune diseases are associated with immune system hyperactivity.

36. Which of the following statements about the male reproductive system is not true?

A. During embryonic development

B. The testis is an external reproductive organ.

C. The testis, epimidymis, and vas deferens are internal reproductive organs.

D. The ejaculate contains 300-600 million sperm cells.

37. Which of the following statements about the male reproductive system is true?

A. Maturation of sperm lasts 42 days.

B. The sperm has a body and several processes.

C. The epididymis contains 250-300 lobules.

D. The prostate gland envelops the beginning of the urethra.

38. Which of the following statements about the female reproductive system is not true?

A. Internal reproductive organs are the uterus, fallopian tubes, and vagina.

B. About 450 ova mature during a woman's period of sexual maturity.

C. The release of an egg from the ovary is called ovulation.

D. The corpus luteum is formed in the uterus after ovulation.

39. Which ofthe following statements about the female reproductive system is true?

A. The uterus is located in the lesser pelvis in front of the urinary bladder.

B. The uterine wall contains well-developed striated musculature.

C. The fallopian tubes are covered on the inside with ciliated epithelium.

D. The menstrual cycle in a woman is most often 18 days long.

40. Which of the following statements about human embryonic development is not true?

A. Human fertilization is internal.

B. Fertilization most commonly takes place in the fallopian tube.

C. During the first few weeks, the fetus is nourished by the uterine mucosa.

D. The fetal circulation has no direct contact with the maternal circulation.

41. Which of the following statements about human embryonic development is true?

A. Three germ layers form about day 6-7 after fertilization.

B. During the first few weeks

C. After the first month of development

D. The blood circulation of the fetus is connected to the maternal circulation.

42. Which of the following statements about the human central nervous system is true?

A. The CNS consists of the brain and 12 pairs of cranial nerves.

B. The brain of a newborn weighs on average 1250 g.

C. After the age of six, the mass of the brain begins to decrease.

D. Inside the brain there are fluid-filled cavities.

43. Which of the following statements about the brain is true?

A. Control centers for circulation and respiration are located in the midbrain.

B. The diencephalon is the middle part of the brain stem.

C. The vagus nerve exits from the midbrain.

D. The midbrain has centers of the systems of vision and hearing.

44. Which of the following statements about the brain is not true?

A. The diencephalon is connected to both hemispheres of the cerebrum.

B. The midbrain consists of two thalami and a hypothalamus.

C. The cerebellum is located behind the brainstem.

D. The grey matter of the medulla oblongata is located inside.

45. Which of the following statements about the cerebrum is not true?

A. The cerebrum makes up 80% of the brain mass.

B. The cerebral cortex consists of gray matter.

C.The cerebral cortex is up to 10 mm thick.

D. At the base of the cerebral hemispheres there is grey matter associated with motor activity.

46. Which of the following statements about the cerebrum is true?

A. The posterior frontal lobe is associated with attention

B. The motor area or voluntary movement area is located in the occipital lobe of the brain.

C. The visual area is located in the frontal lobe of the brain.

D. The general sensory area is located in the anterior parietal lobe of the brain.

47. Which of the following statements about the autonomic nervous system is true?

A. The autonomic nervous system is under voluntary control.

B. The central part of the sympathetic system is located in the brainstem.

C. The central part of the sympathetic system is located in the thoracic spinal cord.

D. The parasympathetic system slows down peristalsis and secretion of the stomach and intestines.

48. Which of the following statements about the autonomic nervous system is not true?

A. The autonomic nervous system innervates internal organs

B. Some functions of the system can be affected by a person's emotional state.

C. The two main parts of the system, sympathetic and parasympathetic,have centers in the CNS.

D. The sympathetic system slows down the heart rate.

49. Which of the following statements about the endocrine system is not true?

A. The pituitary gland is connected to the diencephalon.

B.The posterior lobe of the pituitary gland secretes growth hormone.

C. The anterior lobe of the pituitary gland secretes hormones that control the thyroid glanAnswer

D. The posterior lobe of the pituitary gland secretes antidiuretic hormone.

50. Which of the following statements about the endocrine system is true?

A. The main hormone of the pineal gland is oxytocin.

B. The hormone of the parathyroid glands regulates the calcium content in the blood.

C. The adrenal cortex produces adrenaline.

D. The cells of the islets of Langerhans produce thyroxine.

126. During prophase of mitosis, chromosomes are:

1. synthesized

2. condensed

3. replicated

4. segregated

171. Two healthy parents have a son with haemophilia, an X-Iinked recessive disorder. From which parent is the condition inherited:

1. the father

2. the mother

3. either parent

4. both parents

128. Crossing over takes place during:

1. mitotic metaphase

2. I meiotic metaphase

3. I meiotic prophase

4. Il meiotic prophase

83. Electron transport chains are NOT located in:

1. the thylakoid membrane of chloroplasts

2. the cristae of mitochondria

3. the inner membrane of mitochondria

4. the inner nuclear membrane

125. What is segregated during mitotic anaphase:

1. the two sister chromatids of each chromosome

2. the two homologues of each bivalent

3. the two arms of each chromosome

4. the nuclei of the two daughter cells

118. The genetic code is defined as redundant (synonymous) because:

1. almost all organisms share the same genetic code

2. the codons consist of 3 nucleotides

3. two or more codons may specify the same amino acid

4. there are no separation signals between codons

129. Which is true for meiosis but NOT for mitosis:

1. DNA is replicated before the division starts

2. Chromosomes are moved by a spindle

3. Chromosomes are condensed and become compact

4. The number of chromosomes is changed by the division

123. Chromosomes attach to the mitotic spindle by their:

1. centromere

2. long arm

3. short arm

4. end (telomere)

117. Translation uses as adaptor molecules:

1. ribosomal proteins

2. transfer RNAs

3. ribosomal RNAs

4. amino acids

161. In Aa x Aa cross, what will be the proportion of AA individuals in the next generation:

1. 25%

2. 50%

3. 75%

4. 100%

159. The alternative forms of a gene are called:

1. codons

2. sister chromatids

3. bivalents

4. alleles

88. The nucleolus:

1. is a site of ribosomal protein synthesis

2. is surrounded by a single membrane

3. is a site of ribosomal RNA synthesis

4. is surrounded by a double membrane envelope

136. At the moment of ovulation, the oocyte:

1. is a large cell with one polar body

2. is arrested at prophase I of meiosis

3. Is a large cell with two polar bodies

4. is arrested at metaphase I of meiosis

124. Mitotic spindle is made of:

1. actin microfilaments

2.chromatin fibers

3.collagecn fibers

4. microtubules

121. The periods of interphase of the cell cycle are:

1. prophase, metaphase, anaphase and telophase

2. initiation, elongation and termination

3. diploid to haploid state transition during meiosis

4. G1, S and G2

122. Which is the correct order of the cell cycle periods in dividing cells?

1. G1 G2, S

2. Cytokinesis, G1, S,G2, Prophase

3. Prophase, anaphase, metaphase, telophase

4. Anaphase, telophase, metaphase, prophase

152. Normally, the number of dominant alleles of the same gene in a genotype CANNOT be:

1. zero

2. one

3. two

4. three

164. In AA x Aa cross, what will be the proportion of individuals carrying the recessive allele in the next generation:

1. 0%

2. 25%

3. 50%

4. 75%

141. The sex of mammalian embryo:

1. is determined after implantation

2. depends on the oocyte genome

3. occurs at the puberty

4. is determined at fertilization

130. Which process does NOT take place in meiotic prophase l:

1. chromosome condensation

2. DNA replication

3. chromosome conjugation

4. crossing over

195. People of blood group B:

1. have antigen B on their erythrocytes

2. contain anti-B antibodies in their plasma

3. have both A and B antigens on their erythrocytes

4. contain both anti-A and anti-B antibodies in their plasma

157. When both alleles of a gene are phenotypically expressed in the heterozygote, this interaction is called:

1. complete dominance

2. incomplete dominance

3. intermediate inheritance

4. codominance

147. Complete metamorphosis is:

1. the process of embryonic germ layer differentiation

2. formation of embryonic archenteron (primitive gut) and blastopore

3. development by nymph stages before the adult form

4. development with a stage enclosed in a cocoon before the adult form

170. If a female has a particular X-Iinked mutation, it will be transmitted to:

1. all of her daughters

2. half of her daughters

3. all of her sons

4. all of her children

153. A diploid organism having only one copy of a particular allele is called:

1. homozygous

2. hemizygous

3. heterozygous

4. inbred

175. Two genes are called linked if they are located:

1. in the same locus

2. in the same chromosome

3. in the same gamete

4. in the same genotype

146. The developing mammalian embryo becomes fetus:

1. at cleavage stage of embryogenesis

2. during formation of the ectoderm, mesoderm and endoderm

3. before implantation

4. after formation of all the major body organs

165. Which cross will produce phenotypic ratio 1:1?

1. AA xaa

2. AA x aa

3. Aa x Aa

4. Aa x aa

172. Two healthy parents have a son with sickle-cell anemia, an autosomal recessive disorder. From which parent is the condition inherited:

1. the father

2. the mother

3. either parent

4. both parents

162. In Aa x aa cross, what will be the proportion of heterozygotes in the next generation:

1. 25%

2. 50%

3. 75%

4. 100%

135. Which of the following is NOT true for spermatogenesis:

1. the cytoplasm is evenly distributed between gametes

2. meiosis starts at puberty

3. meiosis starts before birth

4. it results in four functional gametes

80. Oxidative phosphorylation:

1. is an anaerobic process of converting glucose to pyruvate

2. phosphorylates ADP to ATP in mitochondria

3. reduces $NAD^+$ (nicotinamide adenine dinucleotide) to NAD.H

4. provides the ATP harvest of glycolysis

43. Which disease is caused by a bacterium?

1. Haemophilia

2. AIDS

3. Tuberculosis

4. Diabetes

140. Mammalian fertilization takes place in the:

1. uterus

2. fallopian tubes (oviducts)

3. ovarian cortex

4. ovarian follicle

148. Incomplete metamorphosis is:

1. the process of embryonic germ layer differentiation

2. formation of embryonic archenteron (primitive gut) and blastopore

3. development by nymph stages before the adult form

4. development with a stage enclosed in a cocoon before the adult form

158. Which inter-allelic interaction makes the heterozygote phenotypically indistinguishable from one of the homozygotes:

1. complete dominance

2. incomplete dominance

3. intermediate inheritance

4. codominance

183. Numerical chromosomal mutations can be:

1. aneuploidies or polyploidies

2. inversions or translocations

3. deletions or duplications

4. dominant or recessive

127. Replication takes place:

1. between the interphase and the prophase

2. before each of the two meiotic divisions

3. after the first meiotic division

4. before the first but not before the second meiotic division

169. If a male has a particular X-Iinked mutation, it will be transmitted to:

1. all of his daughters

2. half of his daughters

3. all of his sons

4. all of his children

137. The differences between oogenesis and spermatogenesis do NOT concern:

1. accumulation of nutritions and mRNA in one of daughter cells

2. the cytoplasmic volume distribution between the daughter cells

3. the mechanism of chromosome distribution to become haploid

4. morphological differentiation of spermatozoa after meiosis

198. Which factor creates the variation needed for evolution:

1. different environmental conditions

2. natural selection

3. interspecific interactions

4. mutation

197. The process of evolution is:

1. reversible

2. reproducible

3. gradual

4. pre-determined

144. Which of the following is called cleavage stage of embryogenesis?

1. Formation of the primary mouth of the embryo (blastopore)

2. Formation of the primitive gut of the embryo (archenteron)

3. Series of mitotic divisions resulting in blastula formation

4. Differentiation of ectoderm, mesoderm and endoderm cells

173. Males receive their X-Iinked genes from:

1. their mother

2. their father

3. either parent

4. both parents

188. X-Iinked mutations CANNOT be transmitted:

1. from father to son

2. from mother to son

3. from father to daughter

4. from mother to daughter

178. Crossing over is NOT possible between genes that are:

1. linked

2. sex-linked

3. X-Iinked

4. not linked

181. Which process is the ultimate source of all genetic variability:

1. cell division

2. mutation

3. recombination

4. crossing over

167. The state of X-Iinked genes in males is called

1. homozygous

2. hemizygous

3. heterozygous

4. native

187. Numerical chromosomal mutations do NOT include:

1. triploidy

2. diploidy

3. trisomy

4. monosomy

186. Structural chromosomal mutations do NOT include:

1. deletion

2. duplication

3. inversion

4. crossing over

139. Meiosis of spermatogenesis:

1. starts at puberty

2. undergoes arrest during metaphase I

3. is completed in the fetal testis

4. starts in the fetal testis

180. Structural chromosomal mutations include:

1. changed nucleotides within a gene

2. extra or lost chromosomes in the karyotype

3. additional sets of chromosomes in the karyotype

4. lost, repeated or inverted fragment of a chromosome

174. Males receive their Y-linked genes from:

1. their mother

2. their father

3. either parent

4. both parents

145. Which of the following does NOT take place during gastrulation?

1. Formation of the primary mouth of the embryo (blastopore)

2. Series of mitotic divisions resulting in formation of blastula

3. Formation of the primitive gut of the embryo (archenteron)

4. Differentiation of ectoderm, mesoderm and endoderm

110. Which of the following is true for both replication and transcription?

1. They use polymerase to synthesize polypeptide chain

2. They both take place in the cytosol

3. They both are catabolic processes

4. They use polymerase to synthesize polynucleotide chain

96. Chromosomes are called homologous if:

1. one of them is X (from the oocyte) and the other is Y (from the sperm)

2. originate from one of the parents only

3. they resemble each other but one is maternal and the other is paterna

4. they are inherited by siblings of the same parents

151. A gene can exist in several forms called:

1. alleles

2. chromatids

3. nucleotides

4. codons

192. Antibodies are produced by:

1. phagocytes

2. erythrocytes

3. B lymphocytes

4. T lymphocytes

154. How many different types of gametes can be produced by an organism with genotype Aa?

1. one

2. two

3. three

4. four

176. Gene linkage can disrupt:

1. the health of the individual

2. sex determination in the offspring

3. the 9:3:3:1 ratio in F2 hybrids in a dihybrid cross

4. the gene expression

108. RNA polymerase connects the nucleotides by:

1. hydrogen bonds

2. peptide bonds

3. non-covalent bonds

4. phosphodiester bonds

90. The chromatin of eukaryotes:

1. is located in their cytosol

2. is a complex of linear DNA and ribosomes

3. exists as circular DNA molecules

4. is a complex of linear DNA and proteins

163. In AA x Aa cross, what will be the proportion of individuals with the dominant trait in the next generation:

1. 25%

2. 50%

3. 75%

4. 100%

109. In transcription:

1. mRNA is the template

2. tRNA carries the monomers

3. new RNA is made of anticodons complementary to codons

4. a gene in DNA is copied into RNA

196. Cell-mediated immunity is based on:

1. T cells

2. B cells

3. plasma cells

4. antibodies

134. To become functional, the spermatozoa must:

1. lose most of their cytoplasm and organelles (ribosomes, ER etc)

2. expand the volume of their cytoplasm

3. extrude two polar bodies

4. be surrounded by protecting envelope (zona pellucida)

200. Mutations occurring in a population are:

1. mostly beneficial

2. caused by factors to which the population must adapt

3. random

4. caused by the need to have diversity

5. Amino acids in polypeptide chains are bound by:

1. covalent bonds

2. ionic bonds

3. hydrogen bonds

4. disulfide bonds

194. People of blood group AB:

1. have genotype AO or BO ($I^A I^Ο or I^BI^O$)

2. have no A or B antigens on their erythrocytes

3. have both A and B antigens on their erythrocytes

4. contain both anti-A and anti-B antibodies in their plasma

84. The ATP synthase is NOT located in:

1. the thylakoid membrane of chloroplasts

2. the cristae of mitochondria

3. the inner membrane of mitochondria

4. the inner nuclear membrane

191. Which condition is caused by a gene mutation:

1. Turner syndrome

2. Klinefelter syndrome

3. Down syndrome

4. hemophilia

138. Meiosis of oocytes:

1. starts at puberty

2. is arrested during metaphase I

3. is completed in the fetal ovarium

4. starts in the fetal ovarium

190. The karyotype 45, YO causes:

1. Turner syndrome

2. Klinefelter syndrome

3. Down syndrome

4. early embryonic death

193. People of blood group O:

1. could be homozygous or heterozygous for the allele O ($Ι^Ο$ )

2. are always homozygous for the allele O ($Ι^Ο$)

3. contain no anti-A and anti-B antibodies in their plasma

4. accept transfused blood of any group

168. Sex-linked genetic disorders:

1. are manifested only in males

2. are manifested only in females

3. are determined by genes located in the mitochondria

4. are determined by genes located in the X chromosome

160. The position of a particular gene in the chromosome is called:

1. allele

2. locus

3. centromere

4. promoter

150. Normally, two alleles of the same gene CANNOT be found in:

1. one organism

2. one somatic cell

3. one gamete

4. one chromosomal set

22. Anticodon of tRNA is complementary to:

1. DNA double helix

2. codon of mRNA

3. the anticodon of the next tRNA

4. rRNA

182. Sickle-cell anemia is caused by:

1. deletion

2. trisomy

3. recombination

4. gene mutation

107. The enzyme RNA polymerase:

1. synthesizes RNA copy using mRNA as a template

2. copies the nucleotide sequence of a gene incorporating T instead of U

3. makes a complementary copy of a gene incorporating U instead of T

4. synthesizes copies of both complementary DNA strands

199. The chimpanzee is:

1. a species closely related to the human

2. a species distantly related to the human

3. a species that is ancestral to the human

4. a species similar to the human because of similar environment

149. Two different alleles of the same gene can be found in:

1. one chromosome

2. one organism

3. one gamete

4. one chromatid

120. During the cell cycle, replication takes place during:

1. G2 period of interphase

2. Metaphase

3. S period of interphase

4. Prophase

91. The human karyotype consists of:

1. 23 pairs of chromosomes including two sex chromosomes

2. 24 pairs of chromosomes including two sex chromosomes

3. 23 pairs of chromosomes plus two sex chromosomes

4. 24 pairs of chromosomes plus two sex chromosomes

177. Two genes CANNOT be linked if:

1. one is represented by a dominant and the other by a recessive allele

2. one is represented by a normal and the other by a mutant allele

3. one is autosomal and the other is sex-linked

4. one is in heterozygous and the other is in homozygous state

143. The number of embryonic germ layers during gastrulation:

1. divides the animals into diploblastic and triploblastic

2. depends on the quantity of yolk stored in the oocyte

3. divides the animals into aquatic and terrestrial

4. depends on the sex chromosome provided by the spermatozoon

142. The sex of mammalian embryo depends on:

1. the number of X chromosomes in the oocyte

2. X or Y sex chromosome of the spermatozoon

3. X or Y sex chromosome of the polar body

4. X or Y sex chromosome of the oocyte

69. In eukaryotic cells, glycolysis takes place in:

1. the cytosol

2. the intermembrane space of mitochondria

3. the matrix of mitochondria

4. the nucleoplasm

184. Structural chromosomal mutations do NOT include:

1. deletions

2. substitutions

3. inversions

4. duplications

119. Interphase:

1. consists of Gl, S and G2 periods of the eukaryotic cell cycle

2. is the phase of mitotic spindle formation in prokaryotic cells

3. is the period of cytokinesis in eukaryotes

4. is the phase of sister chromatid segregation in eukaryotes

133. Crossing over takes place in:

1. meiotic metaphase I

2. mitotic metaphase

3. meiotic prophase Il

4. meiotic prophase I

12. Which function is specific for enzymes?

1. To carry oxygen in blood

2. To bring amino acids to the ribosome

3. To catalyze reactions in the cell To store energy

4. To store eneregy

114. The genetic code:

1. is necessary for transcription

2. consists of 16 nucleotide triplets called codons

3. is necessary for DNA replication

4. consists of 64 nucleotide triplets called codons

131. When do homologous chromosomes segregate during meiosis:

1. in prophase I

2. in anaphase I

3. in metaphase Il

4. in anaphase Il

101. DNA replication:

1. takes place during interphase of the cell cycle

2. lasts until the end of mitotic cell division

3. occurs in prokaryotic cells only

4. occurs in eukaryotic cells only

24. Anticodons are located in:

1. mRNA

2. tRNA

3. rRNA

4. ribosomal proteins

89. The nucleus:

1. contains the circular chromosome of prokaryotes

2. is surrounded by a single membrane in prokaryotes

3. is a site of ribosomal protein synthesis in eukaryotes

4. contains the linear chromosomes of eukaryotes

98. Diploid set of chromosomes have:

1. the cells after the second meiotic division

2. the cells before and after meiosis

3. somatic cells dividing by mitosis

4. the cells after the first meiotic division

82. Fats and proteins become substrates for catabolism by:

1. passing through the mitochondrial membrane to enter the Krebs cycle

2. being converted to glucose by enzymes

3. being oxidized in the electron transport chain

4. being converted to intermediates of glycolysis or the Krebs cycle

93. The human karyotype consists of:

1. 22 pairs of autosomes including two sex chromosomes

2. 22 pairs of autosomes plus two sex chromosomes

3. 23 pairs of autosomes plus two sex chromosomes

4. 24 pairs of autosomes including two sex chromosomes

14. Denaturation is a process in which proteins:

1. are misfolded

2. are synthesized

3. remain unchanged

4. are degraded to amino acids

115. The difference between transcription and translation is that:

1. transcription uses DNA template (a gene) and translation uses mRNA

2. transcription copies both DNA strands and translation just one of them

3. transcription takes place in the ribosomes and translation in thc nucleus

4. transcription produces protein and translation produces RNA

100. Which of the following is NOT true for the karyotype?

1. It can be studied in actively dividing cells

2. It is species-specific

3. It describes the number, size and morphology of chromosomes

4. The normal human karyotype is: 48 chromosomes including XX or XY

16. Which of the following combinations of bases is NOT present in DNA?

1. thymine and adenine

2. uracil and adenine

3. cytosine and guanine

4. guanine and cytosine

7. Disulfide bonds take part in:

1. primary protein structure

2. alpha helical and beta sheet folding of the protein

3. tertiary structure of the protein

4. secondary structure of the protein

59. The Golgi complex:

1. takes part in endocytosis

2. has ribosomes on its membrane

3. forms vesicles with secretions

4. takes part in oxidative phosphorylation

10. Which protein structure requires hydrogen bonds only?

1. Primary

2. Secondary

3. Tertiary

4. Quaternary

44. Which disease is caused by a bacterium?

1. Ebola

2. Mucoviscidosis (cystic fibrosis)

3. Meningitis

4. Haemophilia

8. The linear sequence of amino acids in the protein determines:

1. its primary structure

2. its secondary structure

3. its tertiary structure

4. its quaternary structure

52. In hypertonic environment:

1. water enters the cell, causing it to swell and even to rupture

2. the cell loses water and shrinks

3. water crosses the membrane at the same rate in and out of the cell

4. water is brought into the cell by active transport

50. Diffusion:

1. can be simple or facilitated

2. transports specific proteins across the cell membrane

3. can be active or passive

4. transports the solutes from lower to the higher concentration

26. In which of the following examples is the base pairing correct?

1. thymine - guanine

2. adenine - uracil

3. cytosine - cytosine

4. uracil - cytosine

77. Which of the following is NOT true for glycolysis?

1. It is a metabolic pathway of converting pyruvate to alcohol or lactic acid

2. It is performed by both aerobic and anaerobic organisms

3. It is an anaerobic catabolic pathway

4. It is a metabolic pathway of converting glucose to pyruvate

64. Enclosed by a double membrane is:

1. the eukaryotic cell

2. the nucleolus

3. the mitochondrion

4. the prokaryotic cell

4. What is the type of peptide bond?

1. Ionic

2. Covalent

3. High energy

4. Noncovalent

29. Bonds between complementary nitrogenous bases in DNA are:

1. covalent

2. disulfide

3. hydrogen

4. peptide

189. The karyotype 45, XO causes:

1. Turner syndrome

2. Klinefelter syndrome

3. Down syndrome

4. early embryonic death

1. The protein chain is supported by:

1. phosphodiester bonds between amino acids

2. covalent bonds between nucleotides

3. covalent bonds between monosaccharides

4. peptide bonds between amino acids

2. The molecule of alpha amino acids carries:

1. phosphate group, nitrogenous base and ribose

2. monosaccharide, nitrogenous base and a phosphate group

3. hydrophilic head and two hydrophobic tails

4. amino group, carboxyl group and a side chain

38. What is NOT true about bacteriophages?

1. The infected cell usually dies

2. They infect prokaryotes

3. They are a group of viruses

4. They can infect animal cells

19. The DNA of prokaryotes is:

1. Linear

2. Single-stranded

3. In their nucleolus

4. In their nucleoid

103. DNA polymerase connects the nucleotides by:

1. hydrogen bonds

2. phosphodiester bonds

3. non-covalent bonds

4. peptide bonds

97. Haploid set of human chromosomes:

1. contains 23 pairs of chromosomes

2. contains 22 autosomes plus two sex chromosomes (XX or XY)

3. is made of 22 chromosomes

4. is made of 22 autosomes plus one sex chromosome (X or Y)

15. Renaturation is a process in which proteins:

1. are synthesized

2. remain unchanged

3. are misfolded

4. recover their native state

33. Viruses are:

1. the simplest type of prokaryotes

2. supramolecular complexes of nucleic acids and proteins

3. free living organisms

4. colonial organisms

13. Which of the following proteins is an enzyme?

1. Lipase

2. Hemoglobin

3. Insulin

4. Collagen

48. Osmosis can transport across the cell membrane:

1. carbon dioxide, oxygen and ions

2. non-polar and hydrophobic molecules or compounds

3. specific proteins

4. water molecules

17. Which of the statements below are valid for both DNA and RNA?

1. They form alpha helices and beta sheets

2. They are made of nucleotides

3. They are double helices

4. They are made of polypeptide chains

27. Messenger RNA:

1. is a template for transcription

2. forms a double helix

3. is a template for translation

4. forms the subunits of the ribosome

11. Which function is performed by specific proteins?

1. Templates for RNA synthesis

2. Support and motility apparatus of animal cells

3. Storage of genetic information

4. Templates for DNA synthesis

30. In which of the following examples is the base pairing correct?

1. thymine -guanine

2. adenine - thymine

3. cytosine - cytosine

4. uracil - cytosine

21. Transfer RNA takes part in:

1. bringing amino acids to the ribosome

2. DNA replication

3. cell division

4. the structure of the ribosome

102. During replication of DNA:

1. free nucleotides are covalently bound to the template DNA strand

2. both daughter DNA strands are synthesized continuously

3. only one of the DNA strands is used as a template

4. hydrogen bonds between the template and free nucleotides are formed

104. Replication of DNA:

1. is a catabolic process

2. takes place in the cytosol of eukaryotes

3. forms the two sister chromatids

4. takes place during both mitosis and meiosis

116. Anticodon is:

1. a triplet of ribonucleotides in mRNA

2. recognized by a codon of rRNA

3. a triplet of ribonucleotides in tRNA

4. recognized by a codon in DNA

65. In eukaryotic cell, oxidative phospholysation takes place in the:

1. cytosol

2. rough endoplasmic reticulum

3. Golgi complex

4. mitochondria

9. Which protein structure requires covalent bonds only?

1. Primary

2. Secondary

3. Tertiary

4. Quaternary

35. The term capsid is used for:

1. the viral DNA

2. the viral RNA

3. the protein shell of DNA/RNA

4. the major viral enzyme

45. The bacterial genome consists of:

1. one linear chromosome

2. several linear chromosomes

3. homologous pairs of chromosomes

4. one circular chromosome

23. Ribosomal RNA takes part in:

1. bringing amino acids to the ribosome

2. DNA replication

3. cell division

4. the structure of the ribosome

92. The eukaryotic chromosomes are NOT made of:

1. one or two DNA molecules depending of the period of the cell cycle

2. one DNA molecule after replication

3. one DNA molecule before replication

4. two sister chromatids attached at the centromeric region

105. Transcription:

1. is a process of RNA synthesis on RNA template

2. produces mRNA as a copy of tRNA and rRNA

3. is performed by DNA polymerase

4. is performed by RNA polymerase

39. The HIV virus:

1. is a DNA virus

2. is an RNA virus

3. can be transmitted by mosquitos

4. is controlled by immunization

61. Proteins to be secreted are synthesized:

1. by ribosomes bound to rough endoplasmic reticulum

2. by ribosomes free in the cytosol

3. within the Golgi complex

4. in the smooth endoplasmic reticulum

51. Cell membrane is completely permeable for:

1. proteins

2. glycoproteins

3. ions

4. small uncharged molecules

40. What is the structure of prions?

1. A single strand of DNA

2. DNA or RNA coated with proteins

3. RNA coated with a lipid membrane

4. Only proteins

34. Viruses cannot multiply outside of a host cell because:

1. of the difference in temperature

2. no viruses exist outside the cell

3. of the high oxygen level

4. they need the cell anabolic apparatus

106. Transcription:

1. is end to end copying of genomic DNA

2. synthesizes DNA copies of genes only

3. produces the mRNA, rRNA or tRNA as copies of their genes in DNA

4. synthesizes mRNA only

49. Diffusion can transport across the cell membrane:

1. monosaccharides

2. carbon dioxide and oxygen

3. amino acids

4. specific proteins

99. Diploid set of chromosomes is formed if:

1. diploid precursor cells undergo meiosis

2. haploid cells are fused to form a zygote

3. oocyte divides its cytoplasm unevenly extruding a first polar body

4. oocyte divides its cytoplasm unevenly extruding a second polar body

58. Which of the following does NOT take place in the smooth endoplasmic reticulum?

1. Phospholipid, fat, and steroid synthesis

2. Accumulation of calcium ions

3. Detoxification of some toxins and alcohol

4. Protein synthesis

95. Nucleolar organizer:

1. is the primary constriction dividing the chromosome into two arms

2. is a chromosomal region attached to the nuclear envelope

3. is a region of chromosomes that contain ribosomal RNA genes

4. is a complex of proteins forming the nuclear pores

57. The smooth endoplasmic reticulum is involved in:

1. intracellular digestion

2. phospholipid, fat, and steroid synthesis

3. nucleic acids synthesis

4. protein synthesis

54. In isotonic environment:

1. water enters the cell, causing it to swell and even to rupture

2. the cell loses water and shrinks

3. cell membrane becomes impermeable to water

4. water crosses the membrane at the same rate in and out of the cell

32. Which disease is caused by a virus?

1. Hepatitis B

2. Atherosclerosis

3. Tuberculosis

4. Down syndrome

31. Complementary bound (double stranded) regions could be formed within the chain of:

1. mRNA

2. polypeptides

3. rRNA and tRNA

4. polysaccharides

60. Which of the organelles has single membrane?

1. Ribosome

2. Mitochondrion

3. Lysosome

4. Centrosome

28. Which nitrogenous base is NOT found in DNA?

1. adenine

2. thymine

3. cytosine

4. uracil

76. Glycolysis harvests chemical energy by:

1. converting glucose into two molecules of pyruvate

2. oxidizing glucose to $CΟ_2$

3. oxidative phosphorylation

4. alcoholic fermentation

56. The rough endoplasmic reticulum is involved in:

1. protein synthesis

2. phospholipid, fat, and steroid synthesis

3. detoxification of some toxins and alcohol

4. cell division

6. The primary structure of proteins is related to:

1. formation of alpha helix

2. folding in a beta sheet

3. the sequence of amino acids

4. formation of phosphate and hydroxyl ends

25. Codons are located in:

1. rRNA

2. ribosomal proteins

3. mRNA

4. tRNA

18. Which nitrogenous base is NOT found in RNA?

1. adenine

2. thymine

3. cytosine

4. uracil

53. In hypotonic environment:

1. the cell loses water and shrinks

2. water crosses the membrane at the same rate in and out of the cell

3. water enters the cell, causing it to swell and even to rupture

4. water is brought out of the cell by active transport

41. The prions are:

1. made of RNA and infect plant cells

2. made of DNA and infect skin cells

3. made of proteins and infect brain cells

4. none of the above

72. Which process takes place in the cytosol of eukaryotic cells?

1. Oxidative phosphorylation

2. Transcription

3. Glycolysis

4. Krebs cycle

66. Which of the following processes does NOT take place in mitochondria?

1. glycolysis

2. oxidative phosphorylation

3. ATP synthesis

4. Krebs cycle

42. What is the most important feature of prokaryotes?

1. They have no membrane-bound nucleus

2. They can multiply only inside a host cell

3. They lack ribosomes

4. They have multiple chromosomes

47. Which statement is NOT true about bacteria?

1. Some species can endure extreme conditions

2. In favorable conditions bacteria can divide every 20 minutes

3. Bacteria cannot be attacked by viruses

4. Some species have flagella

36. Viruses infect cells by:

1. injecting their nucleic acid into the cell or entry via phagocytosis or fusion

2. dissolving the cell membrane using enzymes

3. using infected bacteria to get into the eukaryotic cells secreting antibodies

4. secreting antibodies

70. In eukaryotic cells, the Krebs cycle takes place in:

1. the cytosol

2. the intermembrane space of mitochondria

3. the matrix of mitochondria

4. the nucleoplasm

46. The bacterial cell is surrounded by:

1. capsid

2. cell membrane and cell wall

3. cell membrane only

4. double membrane envelope

78. Glycolysis is:

1. anaerobic catabolic pathway in the lysosomes

2. aerobic metabolic cycle in the cytosol

3. process of oxidative phosphorylation in the mitochondrial matrix

4. anaerobic catabolic pathway in the cytosol

62. In which cells would you expect to find most abundant lysosomes?

1. Prokaryotic cells

2. Ovarian cells that produce hormones

3. Phagocytes that engulf bacteria

4. Muscle cells

75. Substrate-level phosphorylation takes place in:

1. the lumen of smooth endoplasmic reticulum

2. the intermembrane space of mitochondria

3. the respiratory chains of the inner mitochondrial membrane

4. the cytosol during glycolysis

68. Where are electron transport chains located?

1. In the membrane of the rough endoplasmic reticulum

2. In the outer nuclear membrane

3. In the inner mitochondrial membrane

4. In the outer mitochondrial membrane

67. Which of the following structures is NOT a part of mitochondria?

1. ATP synthase complex

2. Electron transport chain

3. Histones

4. Double membrane

63. Enclosed by a double membrane is:

1. the eukaryotic cell

2. the nucleus

3. the nucleolus

4. the prokaryotic cell

94. Centromere:

1. is the structure that forms the spindle during cell division

2. is a primary constriction dividing the chromosome into two arms

3. contains the ribosomal RNA genes of the cell

4. is the organizing center of microtubule cytoskeleton in eukaryotic cell

87. The nuclear envelope:

1. surrounds the nucleolus

2. is formed by outer and inner membranes

3. contains the ATP synthase

4. is connected to the membranes of Golgi complex

55. For the active transport across the cell membrane is NOT true that:

1. It is ATP dependent

2. It is ATP independent

3. It uses protein transporters

4. It is against the concentration gradient

74. What is oxidative phosphorylation?

1. Production of phospholipids

2. ATP production in mitochondria

3. Oxidation of NAD (nicotinamide adenine dinucleotide)

4. ATP production in the cytosol

111. Ribosomes are organelles:

1. surrounded by a single membrane

2. located on the inner nuclear membrane

3. located on the rough endoplasmic reticulum

4. that synthesize polynucleotide chain

112. The ribosome is NOT:

1. supramolecular complex of rRNA and proteins

2. the organelle that connects amino acids by peptide bonds

3. found on the outer nuclear membrane

4. supramolecular complex of DNA and proteins

79. The redox reactions of electron transport (respiratory) chain:

1. connect glycolysis to the Krebs cycle

2. produce a net amount of 2 ATP per glucose molecule

3. take place in the mitochondrial matrix

4. provide energy to ATP synthase

86. The cell nucleus:

1. is a site of transcription and translation

2. is a site of replication and transcription

3. is surrounded by a single membrane

4. is not surrounded by a membrane

113. Synthesis of rRNA takes place in the:

1. ribosomes

2. rough endoplasmic reticulum

3. nucleolus

4. inner nuclear membrane