Cytokinin signals to nuclear-localized response regulators  by transferring the phosphate group to an aspartate on the receiver domain of the ARR. The ARR response regulators are encoded by multigene families, They fall into two basic classes:

I) Type-A ARRs

II)Type-B ARRs

a) The products of which are made up solely of a receiver domain

b) Receiver domain also include an output domain containing DNA-binding  transcription activation sites

c) Which negatively regulate cytokinin signaling by interacting with other proteins in a manner dependent on the phosphorylation state

d) Which are activated by phosphorylation, which enables them to regulate the transcription of a set of target genes

e) Which are targeted by F-box proteins called KISS ME DEADLY (KMD) proteins negatively regulates the cytokinin response

Which of the following are the correct explanation of the given ARRs types  classes of response regulator?

#Question id: 4634

#Unit 11. Evolution and Behavior

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?

#Question id: 4635

#Unit 11. Evolution and Behavior

Which statement about natural selection is most correct?

#Question id: 4636

#Unit 11. Evolution and Behavior

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?

1. Well-adapted individuals leave more offspring than do poorly adapted individuals.

2. A change occurs in the environment.

3. Genetic frequencies within the population change.

4. Poorly adapted individuals have decreased survivorship.

#Question id: 4637

#Unit 11. Evolution and Behavior

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?

A) The amount of available food may have increased.

B) The number of predators may have decreased.

C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive.

Choose correct combination,

#Question id: 4639

#Unit 11. Evolution and Behavior

If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of the

#Question id: 4640

#Unit 11. Evolution and Behavior

During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?