JAMB Biology Past Questions & Answers - Page 33

161.

The host of liver fluke are ______?

A.

pig and snail

B.

pig and sheep

C.

sheep and snail

D.

pig

Correct answer is C

Liver fluke (Fasciola hepatica) is a parasite affecting a range of livestock and other species. Final hosts in which it can develop to sexual maturity include livestock such as sheep, cattle, horses, goats, alpacas and deer. People can be infected by eating water cress growing along creeks in fluke-infested country.

162.

Carbon (iv) oxide is added to the atmosphere when ________?

A.

plants build-up organic compounds

B.

plants absorb mineral salts

C.

sugars are completely broken down in animals

D.

there is thunderstorm

Correct answer is C

No explanation has been provided for this answer.

163.

The most efficient respiratory structure used by free living protozoan is ________

A.

body surface

B.

gills

C.

buccal cavity

D.

spiracle

Correct answer is A

Protozoa do not have any organellae for the process of respiration. The limiting permeable membrane (body surface) acts as a respiratory surface.
The free molecular oxy¬gen from the surrounding media enters into the body by diffusion. Presence of a cyto¬chrome system has been demonstrated in protozoa.

164.

Gregor Mendel is regarded as the father of ______

A.

variation

B.

genetics

C.

mycology

D.

natural selection

Correct answer is B

Gregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance.

He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits.

165.

Erythrocytes are known as ________

A.

white blood cell

B.

red blood cells

C.

phagocytes

D.

leucocytes

Correct answer is B

A red blood cell(erthyrocytes), which (in humans) is typically a biconcave disc without a nucleus.

Erythrocytes contain the pigment haemoglobin, which imparts the red colour to blood, and transport oxygen and carbon dioxide to and from the tissues.