Which one of the following components of urine in a healthy human does not differ much in concentration from that of blood plasma?

• NH₄ ⁺

• K⁺

• Na⁺

• SO₄ ^2-

The apoplast is located

• outside the plasma membrane

• in the entire cytosol

• on both sides of plasma membrane

• in the plastidial content

The aleurone synthesises and secretes digestive enzymes that hydrolyse nutrients stored in the endosperm, in the presence of

• auxin

• gibberellin

• cytokinin

• ethylene

ATP synthesis in cell requires

• H⁺ gradient across the membrane

• K⁺ gradient across the membrane

• PO₄ ^3- gradient across the membrane

• Ca²⁺ gradient across the membrane

15.

Which one of the following acts solely as an inhibitory neurotransmitter?

• Norepinephrine

• Gamma ($\mathrm{\gamma }$) amino butyric acid

• Acetylcholine

• Dopamine

Which one of the following is called intra-specific chemical messenger?

• Pheromones

• Prostaglandins

• Corticotrophin

• Catecholamines

Grittiness of pear fruit is caused by

• sclereides

• raphides

• collenchyma

• dead parenchyma cells

Which one of the following secretes glucagon?

• Beta ($\mathrm{\beta }$) cells of islets of Langerhans

• Alpha ($\mathrm{\alpha }$) cells of islets of Langerhans

• Acidophilic cells of adenohypophysis

• Basophilic cells of adenohypophysis

Osteoid refers to

• the smallest bone of the body

• young hyaline matrix of true bone in which calcium salts are deposited

• membranous ossification of cranium

• the largest bone of the body

The bundle of axons in the central nervius system is known as

• nerve

• ganglion

• tract

• neuron