Biology MCQs - MCQtimes.com

Homeostasis

How would the hypothalamus respond if its osmoreceptors noticed an increase in plasma osmotic pressure? It would send a message to:

The posterior pituitary to release more ADH

The posterior pituitary to release less ADH

The adrenal cortex to release less aldosterone

The atria to release more ANP

The hypothalamus would respond in a way that opposed the rise in osmotic pressure. Releasing more ADH would make the distal convoluted tubules of the nephrons to become more permeable to water. This would allow more water to be reclaimed from the filtrate which would act against the osmotic pressure of the plasma from rising further. It would also stimulate thirst.

Author: rikazzz Comment

Coordination and Control

The messages carried by a neuron is called:

Nerve code

Reflex arc

Nerve impulse

Brain signal

Nerve impulses are simply signals that are transmitted along nerve fibres (or neurons). It is the process by which neurons communicate with one another. The transmission of a nerve impulse along a neuron from one end to the other occurs as a result of difference in electrical charges across the membrane of the neuron. Nerve impulses can travel very quickly because they are electrical impulses.

Author: rikazzz Comment

Reproduction System

The number of haploid microspores within each ovule is

1

2

3

4

Author: rikazzz Comment

Coordination and Control

Rate of reabsorption of water from nephrons is increased by

oxytocin

vasopressin