According to the Cholodny–Went model of phototropism, the tips of grass coleoptiles have specialized functions such as

a) Production of auxin

b) Perception of a unilateral light stimulus

c) Lateral transport of IAA in response to the phototropic stimulus

Which of the following given above functions is correct?

#Question id: 3562

#Unit 8. Inheritance Biology

In cats, blood-type A results from an allele (IA) that is dominant over an allele (iB) that produces blood-type B. There is no O blood type. Two heterozygous was intercross. What is the probability of first offspring blood-type B?

#Question id: 13142

#Unit 10. Ecological Principles

The Norway rat (Rattus Norvegicus), a widespread pest, was controlled for about a decade by the anticoagulant warfarin. This chemical substance, placed in food pellets, is absorbed by the intestinal tract and inhibits the clotting of blood. After a population decline for about 10 years, rat populations increased and stabilized. In one European population, as illustrated in the graph below, the percentage of rats resistant to warfarin has remained fairly stable over a number of years.

Resistance to warfarin is governed by a dominant autosomal gene, R. More than 15 percent of the resistant animals are heterozygous at this locus (Rr). The table below indicates the response to warfarin and relative reproductive fitness of individuals that are homozygous or heterozygous for the dominant gene (R). The RR individuals have a 20-fold increase in vitamin K requirement over individuals.

#Question id: 19871

#Unit 13. Methods in Biology

#Question id: 28644

#Unit 2. Cellular Organization

CDK activity is high in which phase of the cell cycle?

#Question id: 19096

#Unit 6. System Physiology – Plant