Following statements are regarding to the mechanism of thick filament regulation.

A. In vertebrate smooth muscle, phosphorylation of the myosin regulatory light chain (LC) activates contraction.

B. At Ca2+ concentrations of more than 10−6 M, the regulatory light chain is not phosphorylated, and the myosin adopts a folded conformation.

C. When the Ca2+ level rises, Ca2+ binds calmodulin (CaM), which undergoes a conformational change (CaM*). The CaM*-Ca2+ complex binds and activates myosin light chain kinase (MLC kinase), which then phosphorylates the myosin LC. This phosphorylation event unfolds the myosin II, which is now active and can assemble into bipolar filaments to participate in contraction.

D. When the Ca2+ levels drop, the myosin LC is dephosphorylated by myosin light-chain (MLC) phosphatase, which is dependent on Ca2+ for activity, causing muscle relaxation.

Which of the following combination is correct?

#Question id: 3502

#Unit 9. Evolution & Diversity of Life Forms

Sexual dimorphism (SD) is a pattern that is seen throughout the animal kingdom and differences between the sexes in coloration are common in many organisms. Following some statement are given

A) There are many mechanisms that drive the evolution of SD, the most accepted mechanism being sexual selection

B) Mate choice is an important proximate mechanism of sexual selection, often the sex with the higher reproductive investment is the ‘choosy’ sex

C) Larger species are more sexually dimorphic than smaller species

D) Terrestrial species tend to be more sexually dimorphic than arboreal species

Which of the following above statement is correct?

Which one of the following is correct?

#Question id: 3503

#Unit 9. Evolution & Diversity of Life Forms

Following figure shown mate choice, following some statement is given

A) Male mate choice

B) More variance of matting success in female

C) Polygyny

D) More variance of matting success in male

E) Female mate choice

F) Polyandry

#Question id: 3504

#Unit 9. Evolution & Diversity of Life Forms

Bird has a choice of four food resource with following character . assume all resource are equally abundant Following sequence of preference for resource ?

#Question id: 3505

#Unit 9. Evolution & Diversity of Life Forms

Patterns of relatedness are different in hymenopterans, which are haplodiploid. Which of the following value of relatedness R1, R2, R3 and R4 respectively in figure?

#Question id: 3506

#Unit 9. Evolution & Diversity of Life Forms

An altruist provides help worth 9 units of fitness to a recipient, at a personal cost of 2 unit of fitness. As per kin-selection theory, the minimum value of genetic relatedness between the actors and the recipients that is necessary to maintain altruism in the population is

#Question id: 3507

#Unit 9. Evolution & Diversity of Life Forms

Rank the following from most general to most specific:

A. gametic isolation

B. reproductive isolating mechanism

C. pollen-stigma incompatibility

D. prezygotic isolating mechanism