Answer:
Option A
Explanation:
Thyroid is primarily caused by lack of iodine but there are other reasons as well that lead to increased size of the thyroid gland. Some of these reason is
a) over- or underproduction of thyroid hormones
b) Nodules in the glans
Some times, due to overstimulation immune system itself attack the thyroid gland thereby producing excess thyroxine and hence causing the thyroid to swell
Thus, Option A is correct
Answer:
External fertilization usually occurs in aquatic environments where both eggs and sperm are released into the water Most external fertilization happens during the process of spawning where one or several females release their eggs and the male(s) release sperm in the same area, at the same time.
Typically, frogs lay eggs. This process usually occurs through external fertilization, where the female releases her eggs from her body into water. Then, the male releases his sperm to fertilize them In this case, the eggs are fertilized inside the female's body before they are released.
Answer:
It becomes something like that
It becomes firm/turgid if it were an animal cell it would've burst but the cell wall prevents it from doing so.
Answer:
The correct answer is allopatric speciation.
Explanation:
Allopatric speciation occurs when a geographical barrier comes between a species population living in the same area. This geographical barrier separates the population into two different geographical area which do not have the same condition.
So as both the separated population get different habitat environment to live so they evolve differently from each other. So natural selection and genetic drift works differently in both the population which brings genetic changes in the population and helps in creating a new species.
