POST UTME UNILORIN 2021 Biology | Objective

Are you preparing for POST UTME UNILORIN exams? Reviewing past questions is one of the most effective ways to guarantee a high score. This practice hub features authentic 2021 Biology (Objective) questions designed to simulate the real exam environment.

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Question 1
In a eukaryotic cell, the process of mitosis is initiated by the breakdown of the nuclear envelope, which is triggered by the activation of the protein kinase Cdk1. What is the primary function of Cdk1 in this process?
Correct A. To phosphorylate and activate the nuclear lamina
B. To degrade the nuclear envelope
C. To regulate the spindle assembly checkpoint
D. To control the condensation of chromatin

Correct Answer: A

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Question 2
The diagram below shows a cross-section of a plant root. Which of the following tissues is responsible for the absorption of water and minerals from the soil?
A. Cortex
Correct B. Endodermis
C. Pericycle
D. Xylem

Correct Answer: B

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Question 3
The process of osmoregulation in animals involves the regulation of the concentration of solutes in the body fluids. Which of the following organs plays a crucial role in this process?
Correct A. Kidneys
B. Liver
C. Pancreas
D. Adrenal glands

Correct Answer: A

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Question 4
The diagram below shows a simplified representation of the human eye. Which of the following structures is responsible for the accommodation of light rays?
A. Cornea
B. Iris
Correct C. Lens
D. Retina

Correct Answer: C

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Question 5
The process of meiosis in eukaryotic cells involves the reduction of the chromosome number by half. Which of the following stages of meiosis is responsible for this reduction?
A. Prophase I
B. Metaphase I
Correct C. Anaphase I
D. Telophase II

Correct Answer: C

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Question 6
The process of natural selection acts on variation in a population, leading to the evolution of adaptations that enhance survival and reproductive success. Which of the following is an example of an adaptation that has evolved as a result of natural selection?
A. The development of antibiotic resis\tance in bacteria
Correct B. The evolution of the peppered moth's dark coloration
C. The development of the human eye's ability to see in low light
D. The evolution of the giraffe's long neck

Correct Answer: B

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Question 7
In the context of eco\logical succession, what is the term for the process by which a community of organisms becomes established in a new area?
Correct A. Primary succession
B. Secondary succession
C. Eco\logical drift
D. Species invasion

Correct Answer: A

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Question 8
The human body's \endocrine system plays a crucial role in regulating various physio\logical processes. Which of the following hormones is primarily responsible for stimulating the growth and development of bones?
A. Insulin
B. Thyroid-stimulating hormone (TSH)
Correct C. Growth hormone (GH)
D. Adrenaline

Correct Answer: C

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Question 9
The process of photosynthesis occurs in specialized organelles called chloroplasts, which are present in plant cells. What is the primary function of chlorophyll in photosynthesis?
Correct A. To absorb light energy from the sun
B. To convert light energy into chemical energy
C. To transport water and minerals from the roots to the leaves
D. To regulate the opening and clo\sing of stomata

Correct Answer: A

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Question 10
The concept of eco\logical niches refers to the specific role or position that an organism occupies within its environment. Which of the following is an example of a competitive exclusion principle?
Correct A. The presence of two species with identical eco\logical niches in the same environment
B. The presence of two species with different eco\logical niches in the same environment
C. The presence of a \single species with a unique eco\logical niche in an environment
D. The absence of a species in an environment due to the presence of a competing species

Correct Answer: A

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Question 11
In a photosynthetic pathway, which of the following pigments is primarily responsible for absorbing light in the blue-violet region of the visible spectrum?
A. Chlorophyll a
B. Chlorophyll b
C. Carotenoids
Correct D. Phycobiliproteins

Correct Answer: D

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Question 12
A 2.5-g sample of a compound containing only carbon, hydrogen, and oxygen is analyzed by combustion. The amount of carbon dioxide produced is 3.2 g, and the amount of water produced is 1.8 g. What is the empirical formula of the compound?
A. C2H4O
Correct B. C3H6O2
C. C4H8O3
D. C5H10O4

Correct Answer: B

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Question 13
A solution contains 5.0 g of glu\cose (C6H12O6) dissolved in 100 mL of water. What is the molarity of the solution?
A. 0.25 M
Correct B. 0.50 M
C. 0.75 M
D. 1.00 M

Correct Answer: B

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Question 14
A 10.0-mL sample of a solution containing 0.50 M NaCl is diluted to 50.0 mL. What is the concentration of the resulting solution?
A. 0.01 M
Correct B. 0.05 M
C. 0.10 M
D. 0.20 M

Correct Answer: B

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Question 15
A cell has a resting membrane potential of -70 mV. If the cell is depolarized by 10 mV, what is the new membrane potential?
Correct A. -60 mV
B. -70 mV
C. -80 mV
D. -90 mV

Correct Answer: A

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Question 16
A 50.0-mL sample of a solution containing 0.50 M HCl is titrated with 0.50 M NaOH. What is the pH of the resulting solution after the addition of 25.0 mL of NaOH?
A. 7.00
Correct B. 8.00
C. 9.00
D. 10.00

Correct Answer: B

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Question 17
A 10.0-mL sample of a solution containing 0.50 M CaCl2 is diluted to 50.0 mL. What is the concentration of the resulting solution?
A. 0.01 M
Correct B. 0.05 M
C. 0.10 M
D. 0.20 M

Correct Answer: B

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Question 18
A cell has a resting membrane potential of -70 mV. If the cell is hyperpolarized by 10 mV, what is the new membrane potential?
A. -60 mV
B. -70 mV
C. -80 mV
Correct D. -90 mV

Correct Answer: D

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Question 19
A 50.0-mL sample of a solution containing 0.50 M HCl is titrated with 0.50 M NaOH. What is the pH of the resulting solution after the addition of 50.0 mL of NaOH?
A. 7.00
B. 8.00
C. 9.00
Correct D. 10.00

Correct Answer: D

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Question 20
A 10.0-mL sample of a solution containing 0.50 M CaCl2 is diluted to 100.0 mL. What is the concentration of the resulting solution?
A. 0.01 M
B. 0.05 M
C. 0.10 M
D. 0.20 M

Correct Answer: VIEW ANSWER

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Question 21
In a desert e\cosystem, a cactus plant has a high concentration of water-storing cells. What is the primary function of these cells?
Correct A. To protect the plant from excessive water loss
B. To store nutrients for the plant
C. To provide structural support for the plant
D. To regulate the plant's temperature

Correct Answer: A

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Question 22
A patient has been diagnosed with a bacterial infection. The bacteria have developed resis\tance to multiple antibiotics. What is the most likely cause of this resis\tance?
Correct A. Horizontal gene transfer
B. Vertical gene transfer
C. Mutation
D. Gene editing

Correct Answer: A

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Question 23
A river flows through a valley and eventually empties into a lake. What is the primary mechanism by which the river's water is purified?
A. Photosynthesis
B. Respiration
Correct C. Filtration
D. Oxidation

Correct Answer: C

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Question 24
A plant has a high concentration of stomata on its leaves. What is the primary function of these stomata?
A. To regulate the plant's temperature
B. To store water
Correct C. To exchange gases
D. To protect the plant from excessive light

Correct Answer: C

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Question 25
A patient has been diagnosed with a viral infection. The virus has a high mutation rate. What is the primary mechanism by which the virus's genetic material is replicated?
A. DNA replication
Correct B. RNA replication
C. Protein synthesis
D. Gene editing

Correct Answer: B

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