Article Questions

Describe how scientists developed an evolutionary ‘tree of mammals’ (3)

• Fossil records

• Molecular phylogeny

• DNA sequencing

• Amino acid sequences

Explain how small mammals benefit from hibernating during periods of cold weather (4)

• Larger SA:V

• Heat is lost more easily

• Hibernating reduces heat loss

• Reduced metabolism

Explain how decreasing physiological activity could lead to a reduction in body temperature and metabolism (3)

• Reduced rate of respiration

• Respiration releases heat

• Less thermal energy carried around the body

• Less ATP generated for muscle contractions

Explain how a single copy of mRNA could lead to production of many different proteins (4)

• Splicing (introns removed)

• Post-transcriptional changes (exons removed/reordered)

• Modifying order of polypeptide chains

• Change tertiary structure of protein

• Changing function/role

Explain how decreasing body temperature from 37 to 32 would cause a decrease in metabolic activity (5)

• Reduction in thermal energy

• Reduction in kinetic energy for enzymes

• Fewer enzyme substrate collisions

• Products formed decrease

• Reduction in respiration

One function of hypothalamus (1)

• Thermoregulation