JAMB Biology Past Questions & Answers - Page 40

196.

The correct sequence of the movement of urea during urine formation is

A.

glomerulus → Bowman's capsule → convoluted tubule → Henle's loop → collecting tubule

B.

glomerulus → Bowman's capsule → convoluted tubule → Henle's loop → convoluted tubule → collecting tubule

C.

convoluted tubule → glomerulus → Nettle's loop → Bowman's capsule→collecting tubule

D.

convoluted tubule → Bowman's capsule → Henle's loop → glomerulus → collecting tubule

Correct answer is A

The kidneys filter unwanted substances from the blood and produce urine to excrete them.

There are three main steps of urine formation: glomerular filtration, reabsorption, and tubular secretion.

These processes ensure that only waste and excess water are removed from the body.

197.

The sequence of the one-way gaseous exchange mechanism in a fish is

A.

mouth → operculum → gills

B.

mouth → gills → operculum

C.

operculum → gills → mouth

D.

gills → operculum → mouth

Correct answer is B

Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gills. In some fish, capillary blood flows in the opposite direction to the water, causing counter-current exchange. The gills push the oxygen-poor water out through openings in the sides (opercula) of the pharynx.

198.

I. Stomata → Spirogyra

II. Alveoli → Earthworm

III. Malpighian tubule → Mammal

IV. Contractile vacuole → Protozoa

Which of the above structures is correctly matched with the organisms in which it is found?

A.

II

B.

I

C.

IV

D.

III

Correct answer is C

Stomata allow a plant to take in carbon dioxide, which is needed for photosynthesis. They also help to reduce water loss.

The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

The Malpighian tubules are tubular structures that are free floating in the haemolymph and function as excretory and osmoregulatory organs of insects. 

 Contractile vacuoles (in the cells of the lower organisms) protect a cell from absorbing too much water and potentially exploding by excreting excess water.

200.

The order of passage of food in the digestive system is

A.

ileum → caecum →large intestine → rectum

B.

ileum → colon → caecum → rectum

C.

large intestine → ileum → caecum → rectum

D.

colon → caecum → ileum → rectum

Correct answer is A

No explanation has been provided for this answer.