Firstly light is an external stimuli. in plants - shoots are positively phototrophic while roots are negatively phototrophic.
Answer:
pre-zygotic reproductive isolation
Explanation:
<em>The molecules regulate the pre-zygotic reproductive isolation mechanism.</em>
<u>Reproductive isolation generally refers to the variety of biological processes that sustain the formation of new species of biological organisms. </u>
Some of these processes <em>act to prevent fertilization or the formation of zygotes between organisms that are not of the same species</em> (pre-zygotic mechanisms) while others <em>ensure that the product of fertilization is invalid</em> in case the former fails (post-zygotic mechanisms).
Some pre-zygotic mechanisms ensure that there exists no form of mating among organisms that are not of the same species due to incompatible reproductive organs, but where this fails, another pre-zygotic mechanism will act so that that the mating will not lead to fertilization and there will not be formation of zygotes.
The prevention of fertilization between organisms with compatible reproductive organs but of different species is carried out by molecules. These molecules ensure that there are locks and keys in place to prevent the fertilization of the egg by the sperm.
When you upload a photo, I will comment the answer.
The prokaryotic cell is 17 times larger as compared to the virus particle.
Both values first need to be converted to the same unit.
5.0 um = 5.0 x
m
300 nm = 3.0 x
m
Dividing both values:
5.0 x
m/3.0 x
m
= 16.667
Hence, the prokaryotic cell is approximately 17 times bigger than the virus particle.
More on unit conversion can be found here: brainly.com/question/25356892?referrer=searchResults