JAMB Biology Past Questions & Answers

1.

Which of the following structures in the ear is responsible for transmitting sound vibrations to the auditory nerve?

A.

Eardrum

B.

Ossicles

C.

Cochlea

D.

Auditory canal

Correct answer is C

The cochlea is a spiral-shaped structure in the inner ear that is filled with fluid and lined with cells with very fine hairs. These hairs move when the fluid in the cochlea moves, thereby converting sound vibrations into nerve signals that the brain can interpret. Therefore, the correct answer is 'Cochlea.' The eardrum and ossicles help to transmit sound vibrations to the cochlea, but it is the cochlea that transmits these vibrations as signals to the auditory nerve.

2.

Which of the following is a difference between plant and animal cells?

A.

Plant cells have a nucleus, while animal cells do not

B.

Plant cells have a cell membrane, while animal cells have a cell wall

C.

Plant cells contain chloroplasts for photosynthesis, while animal cells do not

D.

Plant cells have a central vacuole, while animal cells have multiple small vacuoles

Correct answer is C

One of the main differences between plant and animal cells is that plant cells contain chloroplasts for photosynthesis, while animal cells do not. However, plant cells contain chloroplasts, which are organelles responsible for photosynthesis, enabling plants to convert sunlight into energy-rich molecules. Animal cells lack chloroplasts and obtain energy through other means, such as consuming organic matter.

3.

Digestive enzymes are responsible for

A.

Breaking down food into smaller molecules

B.

Absorbing nutrients into the bloodstream

C.

Regulating the pH of the digestive tract

D.

Transporting food through the digestive system

Correct answer is A

Digestive enzymes play a vital role in the process of digestion by breaking down food into smaller molecules that can be easily absorbed and utilized by the body. Digestive enzymes are produced by various organs in the digestive system, including the salivary glands, stomach, pancreas, and small intestine.

4.

Which of the following options best describes adaptation for survival in organisms?

A.

Adaptation is the inherited trait that increases an organism's chances of survival and reproduction in its environment

B.

Adaptation is the process by which organisms acquire new characteristics during their lifetime

C.

Adaptation refers to the ability of an organism to change its environment to better suit its needs

D.

Adaptation involves the development of new traits in response to changes in the environment

Correct answer is A

The statement that best describes adaptation for survival in organisms is that it is the inherited trait that increases an organism's chances of survival and reproduction in its environment. It refers to the process by which populations of organisms evolve and become better suited to their environment over time.

5.

Ecological succession refers to

A.

The movement of organisms from one habitat to another

B.

The competition among species for limited resources

C.

The process of natural selection in a population

D.

The gradual and predictable change in a community over time

Correct answer is D

Ecological succession can be primary or secondary. Primary succession occurs in areas where no previous community existed, such as on bare rock or after a volcanic eruption. Secondary succession occurs in areas where a previous community has been disturbed, such as after a forest fire or human disturbance. Throughout the succession process, the community gradually changes in terms of species composition, population sizes, and community interactions, leading to a more stable and mature ecosystem.