JAMB Biology Past Questions & Answers - Page 3

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21.

Which of the following is the correct classification of carbohydrates?

A.

Lipid

B.

Phytonutrient

C.

Macronutrient

D.

Micronutrient

Correct answer is C

Carbohydrates are classified as macronutrients. Macronutrients like carbohydrates are a major source of energy in the diet and are classified as such.

22.

Which of the following organs is primarily responsible for excretion in humans?

A.

Liver

B.

Pancreas

C.

Kidneys

D.

Lungs

Correct answer is C

The kidneys are primarily responsible for excretion in humans. The kidneys are the major excretory organs in humans. They filter waste products, excess ions, and water from the blood to produce urine, which is then eliminated from the body.

23.

Metamorphosis is a biological process that involves

A.

The growth and development of an organism from a zygote to an adult

B.

The change in form and structure during the life cycle of certain organisms

C.

The regeneration of lost body parts in an organism

D.

The transformation of an organism from an adult stage to a larval stage

Correct answer is B

Metamorphosis is commonly observed in certain animal groups, such as insects (e.g., butterflies, beetles) and amphibians (e.g., frogs, salamanders). It involves a dramatic change in body form and structure as an organism progresses through distinct stages of its life cycle. These stages may include egg, larval, pupal, and adult phases.

24.

Which of the following mechanisms is responsible for providing support in plants?

A.

Muscles and bones

B.

Exoskeleton

C.

Endocrine system

D.

Cell walls and turgor pressure

Correct answer is D

The mechanism responsible for providing support in plants is the combination of cell walls and turgor pressure. In plants, the cell walls, composed of cellulose, provide structural support to the cells and tissues. They give rigidity and strength to plant cells, enabling them to maintain their shape and resist external forces. Additionally, turgor pressure, which is the pressure exerted by the cell contents against the cell walls, helps maintain the overall rigidity and upright form of plants.

25.

Which of the following is a primary source of pollution in aquatic ecosystems?

A.

Soil erosion

B.

Industrial discharge

C.

Air pollution

D.

Deforestation

Correct answer is B

Industrial discharge refers to the release of pollutants, such as chemicals, heavy metals, and wastewater, from industrial activities into water bodies. This is a primary source of pollution in aquatic ecosystems. Industries generate various pollutants that are often released into nearby water bodies, leading to water pollution and adverse effects on aquatic organisms and ecosystems.

26.

Which of the following is a plant hormone responsible for promoting cell elongation and growth?

A.

Abscisic acid

B.

Gibberellins

C.

Ethylene

D.

Cytokinins

Correct answer is B

Gibberellins are plant hormones that play a significant role in promoting cell elongation and growth.

27.

Which of the following statements is true regarding sex-linked traits?

A.

Sex-linked traits are located on the sex chromosomes

B.

Sex-linked traits are inherited only from the mother

C.

Sex-linked traits are more commonly observed in females

D.

Sex-linked traits are not influenced by hormonal factors

Correct answer is A

Sex-linked traits are traits that are determined by genes located on the sex chromosomes (X and Y chromosomes in humans).

28.

Which of the following statements best describes the role of competition in the process of adaptation?

A.

Competition leads to the selection of individuals with favorable traits for survival and reproduction

B.

Competition ensures equal distribution of resources among individuals in a population

C.

Competition leads to the development of new traits and adaptations in a population

D.

Competition reduces the need for adaptations as individuals coexist peacefully

Correct answer is A

When individuals within a population compete for limited resources such as food, water, or mates, those individuals with favorable traits that enhance their ability to acquire resources are more likely to survive and reproduce.

29.

Which of the following describes the inheritance of traits from parents to offspring?

A.

Adaptation

B.

Evolution

C.

Natural selection

D.

Genetics

Correct answer is D

Genetics is the field of biology that studies the inheritance of traits from parents to offspring. Genetics encompasses various concepts and principles, including the study of genes, DNA, chromosomes, genetic inheritance patterns, genetic mutations, and genetic variations.

30.

Which of the following is the most inclusive level of classification in the Linnaean system?

A.

Kingdom

B.

Phylum

C.

Domain

D.

Class

Correct answer is A

The most inclusive level of classification in the Linnaean system is the kingdom.