Practice Post UTME UNIBEN biology 2021 Past Questions

Question 1

In a population of Drosophila melanogaster, the frequency of the recessive allele 'a' is 0.2. If the population is in Hardy-Weinberg equilibrium, what is the frequency of the homozygous dominant genotype 'AA'?

Correct A. 0.64

B. 0.36

C. 0.16

D. 0.04

Correct Answer: A

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Question 2

A diagram of the respiratory system is shown below. What is the function of the alveoli?

Correct A. Exchange of oxygen and carbon dioxide

B. Production of surfac\tant

C. Filtering of blood

D. Regulation of breathing

Correct Answer: A

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Question 3

A plant grows in a controlled environment with a cons\tant temperature of 25°C and a photoperiod of 12 hours. What is the expected effect on the plant's growth?

A. Increased growth rate

B. Decreased growth rate

Correct C. No effect on growth rate

D. Increased leaf size

Correct Answer: C

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Question 4

A diagram of a cell is shown below. What is the function of the mitochondria?

A. Protein synthesis

B. Cell signaling

Correct C. Energy production

D. Cell division

Correct Answer: C

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Question 5

A population of rabbits is growing according to the \logistic growth equation. If the carrying capacity is 1000 and the initial population is 100, what is the population size after 5 generations?

A. 500

B. 750

C. 900

Correct D. 1000

Correct Answer: D

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Question 6

In a closed e\cosystem, the rate of respiration in a population of organisms is directly proportional to the square root of the population size. If the initial population size is 1000 and the rate of respiration is 50 units, what is the rate of respiration when the population size reaches 1600?

A. 75 units

Correct B. 80 units

C. 85 units

D. 90 units

Correct Answer: B

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Question 7

A certain species of plant has a growth rate of 20% per day. If the initial population size is 1000, what is the population size after 5 days?

A. 1638

B. 1700

Correct C. 1800

D. 2000

Correct Answer: C

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Question 8

A certain species of animal has a life cycle that consists of four stages: egg, larva, pupa, and adult. The duration of each stage is 1 day, 2 days, 3 days, and 4 days, respectively. If the animal is in the larva stage on day 5, what stage will it be in on day 10?

A. egg

B. larva

Correct C. pupa

D. adult

Correct Answer: C

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Question 9

A certain species of plant has a growth rate of 20% per day. If the initial population size is 1000, what is the population size after 5 days?

A. 1638

B. 1700

Correct C. 1800

D. 2000

Correct Answer: C

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Question 10

A certain species of animal has a life cycle that consists of four stages: egg, larva, pupa, and adult. The duration of each stage is 1 day, 2 days, 3 days, and 4 days, respectively. If the animal is in the larva stage on day 5, what stage will it be in on day 10?

A. egg

B. larva

Correct C. pupa

D. adult

Correct Answer: C

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Question 11

The process of meiosis results in the production of four haploid daughter cells from a \single diploid parent cell. Which of the following is a characteristic of the daughter cells produced during meiosis?

A. They have the same number of chromosomes as the parent cell

Correct B. They have half the number of chromosomes as the parent cell

C. They have a mix of maternal and paternal chromosomes

D. They have a different ploidy level than the parent cell

Correct Answer: B

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Question 12

In the context of population genetics, what is the Hardy-Weinberg principle?

Correct A. The principle states that allele frequencies will remain cons\tant in a population over time

B. The principle states that allele frequencies will change in a population over time

C. The principle states that genotype frequencies will remain cons\tant in a population over time

D. The principle states that genotype frequencies will change in a population over time

Correct Answer: A

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Question 13

What is the primary function of the hypothalamus in the regulation of body temperature?

A. To maintain a cons\tant body temperature

Correct B. To regulate body temperature in response to changes in the environment

C. To produce hormones that stimulate sweating and shivering

D. To produce hormones that inhibit sweating and shivering

Correct Answer: B

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Question 14

In the context of evolutionary bio\logy, what is the term for the process by which a population becomes reproductively isolated from other populations?

Correct A. Speciation

B. Adaptation

C. Mutation

D. Genetic drift

Correct Answer: A

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Question 15

What is the primary function of the pituitary gland in the regulation of growth and development?

Correct A. To produce hormones that stimulate growth and development

B. To produce hormones that inhibit growth and development

C. To regulate the production of hormones by other \endocrine glands

D. To produce hormones that regulate metabolism

Correct Answer: A

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Question 16

In the context of osmoregulation, what is the primary function of the hypothalamus in regulating thirst and hunger?

Correct A. To detect changes in blood osmolality

B. To regulate the release of antidiuretic hormone (ADH)

C. To stimulate the sensation of thirst

D. To control the release of insulin

Correct Answer: A

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Question 17

A diagram of the human eye is shown below. Which part of the eye is responsible for detecting light?

A. Cornea

B. Iris

Correct C. Retina

D. Lens

Correct Answer: C

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Question 18

A geneticist is studying the inheri\tance of a particular trait in a population. Which type of genetic variation is most likely to result in a change in the frequency of the trait?

A. Mutation

B. Gene flow

C. Genetic drift

Correct D. Natural selection

Correct Answer: D

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Question 19

A diagram of the human nervous system is shown below. Which part of the nervous system is responsible for controlling voluntary movements?

A. Central nervous system

B. Peripheral nervous system

Correct C. Somatic nervous system

D. Autonomic nervous system

Correct Answer: C

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Question 20

A bio\logist is studying the structure of a particular protein. Which type of protein is most likely to have a helical structure?

Correct A. Fibrous protein

B. Globular protein

C. Membrane protein

D. Enzyme protein

Correct Answer: A

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Question 21

In the context of growth and regulation, what is the primary function of the gene regulatory network (GRN) in controlling cell fate decisions?

Correct A. To regulate gene expression by controlling transcription factor activity

B. To mediate cell-cell communication and signaling

C. To maintain genome stability and prevent mutations

D. To regulate cell cycle progression and division

Correct Answer: A

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Question 22

A diagram of the human circulatory system is shown below. Which of the following structures is responsible for the regulation of blood pressure?

Correct A. The heart

B. The arteries

C. The capillaries

D. The veins

Correct Answer: A

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Question 23

In the context of respiration and gas exchange, what is the primary function of the alveoli in the lungs?

Correct A. To exchange oxygen and carbon dioxide between the lungs and the bloodstream

B. To regulate the pH of the blood

C. To filter out pathogens and debris from the air we breathe

D. To produce surfac\tant to reduce surface tension in the lungs

Correct Answer: A

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Question 24

A diagram of the human nervous system is shown below. Which of the following structures is responsible for the transmission of nerve impulses?

Correct A. The neuron

B. The axon

C. The d\endrite

D. The synapse

Correct Answer: A

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Question 25

In the context of coordination, what is the primary function of the hypothalamus in regulating body temperature?

A. To produce heat through shivering

B. To lose heat through sweating

Correct C. To regulate the body's thermostat

D. To produce cold through vasoconstriction

Correct Answer: C

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