Practice Questions

TLS Online TPP Program

#Question id: 14900

polymer-trapping model explains symplastic loading in plants, This model states that the sucrose diffussion takes place through cell to cell via plasmodesmata; which of the following prediction about the diffusion mechanism is INCORRECT?

#Unit 6. System Physiology – Plant

Sucrose, synthesized in the mesophyll, diffuses from the bundle sheath cells into the intermediary cells through the abundant plasmodesmata
In the intermediary cells, raffinose is synthesized from sucrose and galactinol, Because of its smaller size, raffinose is able to diffuse back into the mesophyll
Plasmodesmata between the intermediary cells and sieve elements must be wider and allow passage of raffinose and stachyose
Raffinose is able to diffuse into the sieve elements. As a result, the concentration of transport sugar rises in the intermediary cells and the sieve elements.

More Questions

TLS Online TPP Program

#Question id: 16113

#Unit 7. System Physiology – Animal

Which of the behavioural components may not contribute by reducing the exposure of skin to the cold?

TLS Online TPP Program

#Question id: 16114

#Unit 7. System Physiology – Animal

Which of the following hormones are thermogenic?

TLS Online TPP Program

#Question id: 16115

#Unit 7. System Physiology – Animal

Cold environmental temperatures:

TLS Online TPP Program

#Question id: 16116

#Unit 7. System Physiology – Animal

Which of the following hormones acts synergistically with sympathetic nervous system?

TLS Online TPP Program

#Question id: 16117

#Unit 7. System Physiology – Animal

Thyroid hormones are thermogenic, their actions on target tissues result in heat production by following mechanisms:

i. stimulation of Na+-K+ ATPase

ii. increased O2 consumption

iii. increased metabolic rate

iv. increase in the number and activity of mitochondria

which of the following combinations are correct regarding heat production?

TLS Online TPP Program

#Question id: 16118

#Unit 7. System Physiology – Animal

Following statements are regarding to the heat production by the activation of sympathetic nervous system.

A. Activation is stimulation of β receptors in brown fat, which increases metabolic rate and heat production.

B. Activation is stimulation of α2 receptors in brown fat, which increases metabolic rate and heat production.

C. Stimulation of α1 receptors in vascular smooth muscle of skin blood vessels, producing vasoconstriction. Vasoconstriction reduces blood flow to the surface of the skin.

D. Stimulation of α1 receptors in vascular smooth muscle of skin blood vessels, producing vasodilation. Vasodilation reduces blood flow to the surface of the skin.

Which of the following combination is correct?