Arrange the steps of natural selection to describe the evolution of armor among stickleback fish in freshwater lakes. a. Marine stickleback fish had heavy armor.
b. Some freshwater environments became closed systems of lakes with few or no predators.
c. Marine sticklebacks carrying the recessive low-armor Eda mutation spread into freshwater habitats.
d. In freshwater lakes, sticklebacks with less armor produced more offspring than sticklebacks with more armor.
e. A mutation in the Eda gene gave rise to the low-Eda allele, resulting in variation in armor plating.
f. Most stickleback populations in lakes evolved a predominance Of light armor.

then that particular organisms become extinct.

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.

what in the weirdo : o

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.