Root hairs are developed from the

A. root apex

B. epidermis of root

C. vascular bundles

D. endodermis

E. pericycle

In a dicot leaf, guard cells differ from other epidermal cells because they

A. have no definite shape

B. lack nuclei

C. are smaller

D. contain chloroplast

E. lack vacuole

Which of the following structure is NOT found in the female agama lizard?

A. Pre-anal pads

B. Eardrum

C. Gular fold

D. Nasal scale

E. Nuchal crest

Herbs differ from shrubs because they

A. do not produce fruit

B. are useful to herbalist

C. do not become woody

D. are only annual

E. are only perennials

If an organic compound has its hydrogen: oxygen ratio as 2:1, it is likely to be

A. a protein

B. a cabohydrate

C. a fat

D. a fatty acid and glycerol

E. an amino acid

Which of the following elements are necessary for the formation of chlorophyll in a plant?

A. magnesium and iron

B. Calcium and potassium

C. Calcium and sulphur

D. Potasium and sulphur

E. Phosphorus and potassium

Which of the following statements is NOT true of mammalian erythrocytes?

A. They have haemoglobin

B. they appear yellow when looked at singly

C. They are disc shaped

D. The cell are more numerous than leucocytes

E. They have nuclei at maturity

In woody plants, grass and water vapour are transported across the stems by the

A. xylem fibres

B. medullary rays

C. sieve tubes

D. phloem fibres

E. phloem parenchyma

Which of the following substance is not found in urine?

A. Water

B. Sodium chloride

C. Nitrogenous compounds

D. Calcium chloride

E. Nitrogenous salts

The kidneys of all vertebrates act as osmoregulators. This means that they

A. keep the composition of the plasma constant

B. regulate osmotic processes

C. control the volume of blood entering the kidneys

D. decrease the osmotic pressure of the blood

E. increase the osmotic pressure of blood