DNA damage response system

halts cell cycle progression and

recruits DNA repair machinery

when DNA is compromised

TLS Online TPP Program

#Id: 7816

#Unit 10. Ecological Principles

Animals use behavior to survive in cold temperatures

Curling up into a ball to reduce the exposed surface area. 

Penguins may huddle together to conserve heat. 

Bears hibernate, spending the winter in a deep sleep.

TLS Online TPP Program

#Id: 7817

#Unit 10. Ecological Principles

Polar bears and seals have multiple layers of fat, plumage, or fur to keep warm.

Arctic birds often have thick layers of feathers.

TLS Online TPP Program

#Id: 7818

#Unit 10. Ecological Principles

In many endotherms, shivering occurs in cold conditions whereby the body undergoes rapid muscle contractions without any locomotion.

When the body temperature falls, brown fat cells increase their metabolic rate, and hence heat production.

TLS Online TPP Program

#Id: 7819

#Unit 10. Ecological Principles

Many organisms minimize heat loss to the environment via countercurrent heat exchange

TLS Online TPP Program

#Id: 7821

#Unit 10. Ecological Principles

Supercooling – This is ability to withstand freezing

TLS Online TPP Program

#Id: 7822

#Unit 10. Ecological Principles

Glycoproteins can permit some invertebrates to withstand temperatures as low as –18°C without freezing. 

Antarctic fish also have glycoproteins in their blood and some species accumulate sodium, potassium, or chloride ions or urea, all of which lower the blood freezing point.