Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis) that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics. In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species

By examining the phylogenetic tree diagrammed in the figure above, what conclusion can you draw about the species G. microti?

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?