JAMB Biology Past Questions & Answers - Page 9

41.

The alternate form of a gene is

A.

Alternate type

B.

Dominant character

C.

Recessive character

D.

Allele

Correct answer is D

In genetics, an allele is one of two or more versions of a gene that are found at the same place on a chromosome. Alleles can come in different versions, with each version bringing about different phenotypic traits. For example, a gene for flower color may have one allele that produces red flowers and another allele that produces white flowers. Therefore, the alternate form of a gene is an allele.

42.

What are the primary products of photosynthesis?

A.

Carbon dioxide and water

B.

Glucose and oxygen

C.

Glucose and carbon dioxide

D.

Oxygen and water

Correct answer is B

The primary products of photosynthesis are glucose and oxygen. During photosynthesis, plants use sunlight, water, and carbon dioxide to produce glucose, a simple sugar that serves as the main source of energy for the plant. Oxygen is also produced as a byproduct of photosynthesis and is released into the atmosphere.

43.

Which component of blood is responsible for carrying oxygen to the body tissues?

A.

Platelets

B.

White blood cells

C.

Red blood cells

D.

Plasma

Correct answer is C

Red blood cells, also known as erythrocytes, are responsible for carrying oxygen to the body tissues. They contain a protein called hemoglobin, which binds to oxygen in the lungs and transports it to other parts of the body.

44.

What is the primary source of variation in a population?

A.

Gene flow

B.

Mutation

C.

Natural selection

D.

Genetic drift

Correct answer is B

The primary source of variation in a population is mutation. Mutation is a spontaneous change in the DNA sequence of an organism's genome. It introduces new genetic variations by altering the existing genetic information.

45.

Which of the following statements about the heart is true?

A.

The heart is responsible for the production of red blood cells

B.

The heart pumps oxygenated blood to the lungs

C.

The heart receives blood from the kidneys and filters waste products

D.

The heart is a muscular organ that contracts to circulate blood throughout the body

Correct answer is D

The heart is a vital organ in the circulatory system responsible for pumping and circulating blood throughout the body.