Following statements are regarding to the Surveillance mechanisms in cell cycle regulation.

A. Surveillance mechanisms known as checkpoint pathways establish dependencies among cell cycle events and ensure that the next cell cycle event does not occur prior to the completion of a preceding event.

B. In response to DNA damage, two related protein kinases, ATM and ATR, are recruited to the site of the damage, where they activate signaling pathways that lead to cell cycle arrest, repair, and under some circumstances, apoptosis.

C. The spindle assembly checkpoint pathway, which causes initiation of anaphase, utilizes Mad2 and other proteins to regulate APC/CCdc20, which targets securing and mitotic cyclins for ubiquitinylation.

D. The spindle position checkpoint pathway prevents mitotic CDK inactivation when the spindle is mispositioned. In this pathway, localized activators and inhibitors and a sensor that shuttles between them allow cells to sense spindle position.

Which of the following statement is incorrect?

#Question id: 3268

#Unit 11. Evolution and Behavior

A population of insects is in Hardy-Weinberg equilibrium for a gene with alleles A = orange and a = yellow eyes. There are 91% orange and 9% yellow individuals in the population. If the fitness of the yellow phenotype suddenly drops to zero, what will be the allele frequency in the next generation?

#Question id: 3269

#Unit 11. Evolution and Behavior

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of

#Question id: 3270

#Unit 11. Evolution and Behavior

Heterozygote advantage should be most closely linked to which of the following?

#Question id: 3271

#Unit 11. Evolution and Behavior

Consider hemophilia A, a clotting disorder caused by an X-linked recessive allele with a frequency (q) of approximately 1 in 10,000. The frequency of the disease among females and among male respectively

#Question id: 3272

#Unit 11. Evolution and Behavior

Calculate the frequencies of the XO and X+ alleles respectively for this population.

#Question id: 3273

#Unit 11. Evolution and Behavior

The number of forward mutations is equal to the number of reverse mutations then

a) Population is in equilibrium for forward and reverse mutation rates

b) The population is being in Hardy–Weinberg equilibrium

c) No further change in allelic frequency