MCQS in BIOLOGY from SINDH TEXT book

 Biology MCQS

Mcqs(Multiple choice questions)

Helpful for your coming exams and tests specially for MDCAT, JEST test, Board Exams, and so on.

Solve these conceptual MCQS taken from Different topics from SINDH text book.

These MCQS are selectively taken from Chapters like CELL, ENZYMES, REPRODUCTION, photosynthesis any so on.

1. All of the following are components of the Cell Theory EXCEPT

A. all living things are composed of cells.

B. all living things possess mitochondria.

C. cooperation among cells allows for complex functioning in living things.

D. all cells arise from pre-existing cells.

2. Upon bacteriophage infection, the host cell is directed to synthesize viral protein. A

scientist wishing to study the location of this process in the cell might use

A. centrifugation.

B. autoradiography.

C. electrophoresis.

D. phase contrast microscopy.

3. A student is trying to determine the type of membrane transport occurring in a cell. She finds that the molecule to be transported is very large and polar and when transported across the membrane, no ATP is used. Which of the following is the most likely mechanism of transport?

A. Active transport

B. Simple diffusion

C. Facilitated diffusion

D. Exocytosis

4. Which of the following is NOT a type of tissue found in the human body?

A. Connective tissue

B. Nervous tissue

C. Adipose tissue

D. Cytoplasmic tissue

5. Which of the following types of nucleic acid will never be found in a virus?

A. Single-stranded DNA

B. Double-stranded DNA

C. Single- and double-stranded RNA

D. All of these can be found in a virus.

6. Which of the following activities occurs in the Golgi apparatus?

A. Synthesis of proteins

B. Modification and packaging of proteins

C. Breakdown of lipids and carbohydrates

D. Photosynthesis

7. Mitochondrial DNA

A. is circular.

B. is self-replicating.

C. is important in the synthesis of mitochondrial ribosomes.

D. both (A) and (B).

8. Which of the following is NOT a function of the smooth endoplasmic reticulum?

A. Lipid synthesis

B. Poison detoxification

C. Protein synthesis

D. Transport of proteins

9. What is the main function of the nucleolus?

A. Ribosomal RNA synthesis

B. DNA synthesis

C. Cell division

D. Chromosome assembly

10. In which of the following organelles is pH the lowest?

A. Lysosomes

B. Mitochondria

C. Rough ER

D. Chloroplasts

11. Which of the following is NOT a difference that would allow one to distinguish between a prokaryotic and a eukaryotic cell?

A. Ribosomal subunit weight

B. Presence or absence of the nucleus

C. Presence or absence of the cell wall

D. Membrane-bound versus no membrane-bound organelles

12. A researcher treats a solution containing animal cells with ouabain, a poisonous substance that interferes with the Na+/K+ -ATPase embedded in the cell membrane, and causes the cell to lyse. Which of the following statements best explains ouabain’s mechanism of action?

A. Treatment with ouabain results in high levels of extracellular Ca2+

B. Treatment with ouabain results in high levels of extracellular K+ and Na+

C. Treatment with ouabain increases intracellular concentrations of Na+

D. Treatment with ouabain decreases intracellular concentrations of Na+

13. Which of the following is NOT involved in cell movement?

A. Cilia

B. Flagella

C. Actin

D. Centrioles

14. Which of the following statements about enzyme kinetics is FALSE?

A. An increase in the substrate concentration (at constant enzyme concentration) leads to proportional increases in the rate of the reaction.

B. Most enzymes operating in the human body work best at a temperature of 37°C.

C. An enzyme-substrate complex can either form a product or dissociate back into the enzyme and substrate.

D. Maximal activity of many human enzymes occurs around pH 7.2.

15. At which pH would pancreatic enzymes work at maximum activity?

A. 5.3

B. 6.7

C. 7.2

D. 8.5

16. Some enzymes require the presence of a nonprotein molecule to behave catalytically. An enzyme devoid of this molecule is called a(n)

A. holoenzyme.

B. apoenzyme.

C. coenzyme.

D. zymoenzyme.

17. Which of the following factors determine an enzyme’s specificity?

A. The three-dimensional shape of the active site

B. The Michaelis constant

C. The type of cofactor required for the enzyme to be active

D. The prosthetic group on the enzyme

18. Enzymes increase the rate of a reaction by

A. decreasing the activation energy.

B. increasing the overall free energy of the reaction.

C. both (A) and (B).

D. None of the above

19. Bonding between atoms within an enzyme such as trypsin is best described as

A. peptide.

B. saccharide.

C. ionic.

D. van der Waals.

20. In the equation below, substrate C is an allosteric inhibitor to enzyme 1. Which of the following is another mechanism caused by substrate C?

A → enzyme 1 → B → enzyme 2 → C

A. Competitive inhibition

B. Irreversible inhibition

C. Feedback enhancement

D. Negative feedback

21. When lactase hydrolyzes its substrate, lactose, which of the following occurs?

A. Lactase retains its structure after the reaction.

B. Lactose retains its structure after the reaction.

C. Lactase increases the activation energy of the reaction.

D. Lactose decreases the activation energy of the reaction.

22. Which of the following INCORRECTLY pairs a metabolic process with its site of occurrence?

A. Glycolysis—cytosol

B. Citric acid cycle—mitochondrial membrane

C. ATP phosphorylation—cytosol and mitochondria

D. Electron transport chain—inner mitochondrial membrane

23. Which of the following processes has a net reaction of 2Acetyl

CoA + 6NAD+ + 2FAD + 2GDP + 2Pi + 4H2O → 4CO2 + 6 NADH + 2FADH2 + 2GTP + 4H+ + 2CoA

A. Glycolysis

B. Fermentation

C. Tricarboxylic acid cycle

D. Electron transport chain

24. In glucose degradation under aerobic conditions

A. oxygen is the final electron acceptor.

B. oxygen is necessary for ATP synthesis.

C. water is produced.

D. both (A) and (C).

25. Fatty acids enter the catabolic pathway in the form of

A. glycerol.

B. adipose tissue.

C. acetyl CoA.

D. keto acids.

26. In which of the following reactions is the reactant oxidized?

A. FAD → FADH2

B. NAD+ → NADH

C. NADPH → NADP+

D. ADP → ATP

27. Which of the following statements correctly identifies the purpose of fermentation?

A. To use up excess pyruvate formed as a result of glycolysis

B. To produce NAD+ in order to continue glycolysis

C. To produce NADH in order to continue glycolysis

D. To prevent further increases in oxygen debt

28. In which part of the cell would you expect to find cytochrome c?

A. Mitochondrial matrix

B. Outer mitochondrial membrane

C. Inner mitochondrial membrane

D. Cytosol

29. Which of the following is LEAST likely to occur during oxygen debt?

A. Buildup of lactic acid

B. Buildup of pyruvate

C. Decrease in pH

D. Fatigue

30. Autotrophic organisms, as compared to heterotrophs, convert sunlight into bond energy through photosynthesis. Which of the following best describes the type of process that photosynthesis is?

A. Anabolic

B. Catabolic

C. Glycolytic

D. Fermentation

31. In the course of glycolysis

A. NADH is reduced to NAD+

B. NAD+ is oxidized to NADH.

C. glucose is degraded into two molecules of pyruvate.

D. both (A) and (B).

32. Which of the following correctly describes the amount of ATP produced from the high- energy carrier coenzymes?

A. 1 FADH2 → 1 ATP

B. 1 FADH2 → 3 ATP

C. 1 NADH → 1 ATP

D. 1 NADH → 3 ATP

33. What is the total amount of ATP yielded by the catabolism of one glucose molecule via the Krebs cycle?

A. 6 ATPs

B. 12 ATPs

C. 24 ATPs

D. 36 ATPs

34. Which of the following correctly pairs the stage of development of an egg cell with the different periods in its life cycle?

A. From birth to ovulation—prophase II

B. At ovulation—meiosis I

C. At ovulation—meiosis II

D. At fertilization—meiosis I

35. Some studies suggest that in patients with Alzheimer’s disease, there is a defect in the way the spindle apparatus attaches to the kinetochore fibers. At which stage of mitotic division would you expect to see this problem?

A. Prophase

B. Metaphase

C. Anaphase

D. Telophase

36. If you wanted to incorporate a fluorescently labeled adenine into one of the two daughter cells that would arise as a result of mitosis, at which stage of cell development should you add in the nucleotide?

A. G1

B. G2

C. M

D. S

37. According to the endosymbiont hypothesis, mitochondria are bacterial descendants because they formed as a result of a eukaryotic cell engulfing a prokaryotic cell. Based on this, what type of division would you expect to see in mitochondria?

A. Binary fission

B. Mitosis

C. Budding

D. Regeneration

38. Upon ovulation, the oocyte is released into the

A. fallopian tube.

B. follicle.

C. abdominal cavity.

D. uterus.

39. Cancer cells are cells in which mitosis has gone wild. If a cure were found that could target only cancer cells without affecting normal cells, at which point in the cell cycle would the treatment effectively prevent cancer cell division?

A. During the S stage

B. During prophase

C. During metaphase

D. All of the above could work.

40. Which of the following INCORRECTLY pairs the term with its definition?

A. Scrotum—location of the testes

B. Epididymis—site of sperm maturation

C. Vas deferens—tube connecting the epididymis to the prostate

D. Semen—composed of seminal fluid and sperm

41. During which phase of the meiotic cycle does the cell have a diploid number of chromosomes?

A. In the beginning of prophase I

B. At the end of anaphase I

C. At the end of telophase II

D. Both (A) and (B)

42. Which of the following does NOT contribute to genetic variability?

A. Random fertilization of a sperm and an egg

B. Independent assortment of homologous chromosomesIndependent assortment of

C. Crossing over between homologous chromosomes duringmeiosis

D. The interkinesis that occurs during telophase I

43. Which of the following statements correctly identifies a key difference between mitosis and meiosis?

A. In metaphase of mitosis and metaphase of meiosis I, replicated chromosomes line up in single file.

B. During anaphase of mitosis and anaphase of meiosis I, homologous chromosomes separate, but sister chromatids remain attached.

C. At the end of telophase of mitosis and the end of telophase of meiosis I, the daughter cells are identical to the parent cell.

D. During metaphase of meiosis I, homologous pairs of replicated chromosomes line up.

44. The chromosome number of an offspring produced via parthenogenesis would be

A. diploid.

B. haploid.

C. 2N.

D. both (A) and (C).

45. Which of the following is true regarding prophase?

A. The chromosomes separate and move to opposite poles of the cell.

B. The spindle apparatus disappears.

C. The chromosomes uncoil.

D. The nucleoli disappear.