All Free Biology MCQs with Answers
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19,844 questions · page 908 of 993
- A. 30oC
- B. 40oC
- C. 50oC
- D. 20oC
Explanation: Enzymes generally have an optimal temperature at which they exhibit their highest activity.
Correct answer: 40oC- A. Enzymes start to denature
- B. Enzymes start to re-nature
- C. Enzymes work best
- D. Enzymes are reactivated
Explanation: The term "maximum temperature" means the point at which enzymes start to denature (Option A).
Correct answer: Enzymes start to denature- A. Maximum temperature
- B. Absolute temperature
- C. Critical temperature
- D. Optimum temperature
Explanation: Enzymes are biological catalyst, which are used to speed up the rate of chemical reactions taking place in body.
Correct answer: Optimum temperature- A. It increases the enzyme activity
- B. Stops the reaction
- C. Decreases the enzyme activity
- D. Both Options B and C are correct
Explanation: is temperature of a reaction medium increases above the optimum temperature then it stops reaction by decreasing enzyme activity because…
Correct answer: Both Options B and C are correct- A. Denaturation
- B. Composition
- C. Inhibition
- D. Saturation
Explanation: Saturation refers to the point in an enzymatic reaction where all of the enzyme's active sites are occupied by substrate molecules…
Correct answer: Saturation- A. O2
- B. CO2
- C. CO
- D. H2
Explanation: The Bohr effect describes hemoglobin's lower affinity for oxygen secondary to increases in the partial pressure of carbon dioxide and/or…
Correct answer: O2- A. Blood buffer
- B. Neutralization of H2CO3 by Na2CO3
- C. Absorption by leukocytes
- D. Non-accumulation
Explanation: During the transport of carbon dioxide, the blood does not become acidic due to the presence of buffering systems in the blood.When carbon…
Correct answer: Blood buffer- A. Blood buffer
- B. Neutralization of H2CO3 by Na2CO3
- C. Absorption by leukocytes
- D. Non-accumulation
Explanation: Option A: Although much COz is carried-in blood, blood does not become acidic.
Correct answer: Blood buffer- A. 15 ml/100 ml of blood
- B. 19.6 ml/100 ml of blood
- C. 20.1 ml/100 ml of blood
- D. 200 ml/100 ml of blood
Explanation: In 100 ml of blood, there is about 15 g of Hb, so 100 ml of blood has the capacity to bind 19.6ml of oxygen.
Correct answer: 19.6 ml/100 ml of blood- A. Leptotene
- B. Pachytene
- C. Diplotene
- D. Zygotene
Explanation: Leptotene is the first stage of the prophase of meiosis, during which each chromosome becomes visible as two fine threads.
Correct answer: Pachytene- A. Gamete formation
- B. Recombination during cell division
- C. Production of enzymes during cell division
- D. Chromosomal movement towards pole
Explanation: The synaptonemal complex plays a crucial role in several processes related to cell division, particularly during meiosis, which is the…
Correct answer: Recombination during cell division- A. Replication
- B. Recombination
- C. Gene mapping
- D. None of these
Explanation: Option A: Replication refers to the process of DNA replication that occurs before cell division.
Correct answer: Gene mapping- A. Gastrin
- B. Secretin
- C. Insulin
- D. Lipids
Explanation: Hepatic and Pancreatic secretions are also stimulated by a hormone called secretin, which is produced by the intestinal mucosa on the…
Correct answer: Secretin- A. 7.8
- B. 6
- C. 1.8
- D. 1.4
- E. 1.2
Explanation: Explanation for this question will be added soon.
Correct answer: 1.4- A. Dysentery
- B. Piles
- C. Food poisoning
- D. Peptic ulcer
- E. Dyspepsia
Explanation: Explanation for this question will be added soon.
Correct answer: Peptic ulcer- A. Monosaccharide form
- B. Oligosaccharide form
- C. Polysaccharide form
- D. All given options
Explanation: Amylase is found in saliva and breaks starch into maltose and dextrin, an oligosaccharide.
Correct answer: Oligosaccharide form- A. 3
- B. 7
- C. 8
- D. 12
- E. 13
Explanation: In the mouth, as the chewing begins, saliva is released which has the amylase enzyme. The amylase starts breaking down starch to maltose.
Correct answer: 3- A. Vitamin B12 absorption
- B. Protein digestion
- C. Carbohydrate breakdown
- D. Bowel movement
Explanation: Intrinsic factor plays a crucial role in the transportation and absorption of the vital micronutrient vitamin B12.
Correct answer: Vitamin B12 absorption- A. Sensation of taste
- B. Smell of food
- C. Presence of protein food in stomach
- D. Sight of food
Explanation: Presence of proteins in the stomach activates parietal cells to secrete gastric juice.
Correct answer: Presence of protein food in stomach- A. Glycogenolysis
- B. Gluconeogenesis
- C. Deamination
- D. Immunoglobulin synthesis
Explanation: Metabolic role of liver includes Glycogenolysis (conversion of glycogen to glucose), Gluconeogenesis(formation of glucose from…
Correct answer: Immunoglobulin synthesis