Chapter 3 and 4

Stabilizing selection favours _______________ phenotype and acts against both extreme phenotypes

Which ONE is the example for directional selection?

• Birth weight of human babies

• Number of dark-colored moths during the industrial revolution increases

• Small beak size and large beak size finches in the Galápagos Islands increase in number.

• Faster racehorses are bred for better performance.

State ONE difference between stabilizing selection and directional selection

Bottleneck effect occurs when a sudden decrease in the original population size due to natural ___________ or human action. The small surviving population will have a different allele frequency or gene pool from the original population.

After few generations, both founder and bottleneck effect will lead to alleles may be over represented, under represented or __________. Both could lead to speciation.

When an apoenzyme associates with its coenzyme, what is the resulting active complex called?

• enzyme-substrate complex

• active site of enzyme

• holoenzyme

• cofactor

Prosthetic groups can bind tightly and permanently to the active sites of the enzymes. Coenzymes and metal ions bind loosely and ___________ to the active site of the enzyme.

Alanine inhibits pyruvate kinase in glycolysis by changing the conformation of the active site of enzyme. Which type of inhibitor is alanine?

• competitive inhibitor

• metal ion

• non-competitive inhibitor

• coenzyme

Give two differences between alanine and competitive inhibitors.