Question

1. Describe the four different ways that heat exchange can occur between an organism and its environment. Include an explanation of how insulation, circulatory adaptations (countercurrent exchange), evaporative cooling, behavioral responses, and adjustment of metabolic heat production can help an organism balance heat loss and gain.

2. Compare and contrast the dental, stomach, intestinal, and mutualistic adaptations of the vertebrate digestive system based on the type of diet consumed.

Answer 1

1)

Conduction, covection, radiation and evaporation. These are 4 different ways of exchange of heat between organism and environment.

Conduction - transfer of energy by collision of particles.

Convection - transfer of heat by movement of fluid or gas between areas of different temperatures.

Radiation - transmission of energy in forms of waves or particles through space or material medium.

Evaporation - vaporization on surface of liquid as it changes into gas phase. Eg in sweating

Thermal insulation of body by thich layer of subcutaneous fat, body hairs, thick cuticle or leather cover of external body, gas or spaces in body.

Maintenance of high body temperature in homeothermic animals. Redistribution of superficial blood to deep vessels by mechanisms like vascular contraction in superficial vessels.

Increased sweating in response to high temperature is a method of evaporative cooling.

Change in geography of habitats from extreme climate. Eg migration of birds

Hibernation of animals is another behavioral adaptation.

Shivering of body increases body temperature in cold climate. Endotherms use metabolic heat to maintain stable internal temperature. Brown fat dissipate heat to maintain body temperature by metabolism of fat.

2)

Carnivores have sharp teeth for ripping, cutting and tearing flesh. Sharp canines are most important along with sharp incisors. Herbivores have chisel like incisors and flat pre molars and molars.

Omnivores have combined dental features of harbivores and carnivores. Stomach and intestine of omnivores are more like carnivorous animals.

Herbivores have more compartments in stomach. Cellulose undergo foregut fermentation.

In carnivorous animals single chambered stomach and cant digest cellulose.

Herbivores have longer intestine than carnivores to digest food completely.

Many herbivores have mutualistic gut flora to digest plant matter which are not seen in carnivores.