The flow of air and water in or out of the mesophyll layer of a leaf is controlled by the

A. stomata

B. lenticels

C. air space

D. guard cell

Fungi are heterotropic because they

A. have no leaves

B. lack roots

C. are filamentous

D. lack chlorophyll

The major site of photosynthesis in the leaf is the

A. palisade parenchyma

B. mesophyll parenchyma

C. upper epidermis

D. lower epidermis

5 cm³ dilute sodium hydroxide solution and 5 cm³ one percent copper sulphate solution are added to a solution of food specimen. The purple colour which is observed shows the presence of

A. glucose

B. starch

C. fat

D. protein

The blood vessel which carries blood from the alimentary canal to the liver is the

A. hepatic artery

B. hepatic vein

C. hepatic portal vein

D. mesenteric artery

Gaseous exchange in Aves occurs in the

A. tracheoles

B. bronchi

C. air sacs

D. trachea

In the absence of oxygen, the pyruvic acid produced during glycolysis is converted to CO₂ and

A. water

B. glycerol

C. ethanol

D. citric acid

The excretory organ in insects is the

A. kidney

B. malpighian tubule

C. flame cell

D. nephridium

The structure labelled 5 is the

A. sweat gland

B. sebaceous gland

C. blood vessel

D. nerve fibre

Melanin and keratin are produced in the part labelled

A. 2

B. 3

C. 4

D. 5