There could be many answers to this question, but a possible one is embryo!!
Answer:
Deleterious alleles appear sporadically in a population
Explanation:
A population with a deleterious allele will have no or few individuals that have the ability to pass along these traits. These alleles appear less in a population because of selective pressure but they are not always absent. The alleles appear less often but are are not always passed on and the others that are genetically fit are able to pass along their genes. The reason the population equilibrium is not zero is because these alleles do appear but they are not necessarily passed along. These individuals may not be able to reproduce or reach the age of reproduction.
Deleterious alleles appear more often, making individuals less fit genetically, i.e. they pass fewer copies of their genes to future generations. Put another way, natural selection purges the deleterious alleles.
Answer/Explanation:
Types of reproductive isolation include: temporal, ecological, mechanical, and behavioural.
A snail with a flat disc-like shell will not be able to mate with a snail having a conical shell - this is an example of mechanical isolation, where the animals are physically unable to mate due to incompatible body shapes and sizes.
The reproductive organs of male bush babies do not match with the reproductive organs of females of other bush baby species. - this is another example of mechanical isolation, as the sexual organs will physically not allow reproduction between these species
The mating call of a cricket is not recognized by a cricket of other species - this is an example of behavioural isolation, which results from incompatible mating rituals. I.e. the animals do not respond to each others mating behaviours
The signals sent by a male firefly are not recognized by the female firefly of other species. - this is also an example of behavioural isolation.
Temporal isolation is where species cannot interact because they do not have the same mating seasons or are not active at the same type of day. ?Ecological isolation occurs when two species do not come into physical contact to one another because they access different areas of the habitat. E.g. mating zones, food sources or nesting sites.
What is the word that describes the path of the sun, moon and zodiac as they "move" across the sky? Ecliptic is the answer.
