Ventilation maintains a steep concentration gradient, blood at the exchange surface usually has lower O2 and higher CO2 content than the air (of for fish, the water) at the exchange surface. This is what allows for diffusion of O2 into the blood and CO2 out of the blood. Multicellular organisms have a greater number of cells so will have a higher energy demand than single cellular organisms, this demand can only be met by allowing the cells to respire, a ventilation system brings oxygen molecules which are a raw product of respiration into the hemoglobin of the blood to be transported to tissues. As surface area : volume ratio is very low so if there was no ventilation system and the organism instead relied on exchange of materials through the exposed skin it would be very difficult to met the high energy demand as less O2 and CO2 would be able to be exchanged.
The first reason is that Thats because the seeds will remain dormant until they have the resources they need for eg: some seeds are frozen in winter so that they wont germinate until they have enough resources in spring .
A role in ones environment is a niche
Answer:
The answer is option D. The retina is interrupted by the optic nerve.
Hope it helps........ pls mark as brainliest
Answer: Hope This Helps!
Explanation:
Apart from analysis of genome sequence data, bioinformatics is now being used for a vast array of other important tasks, including analysis of gene variation and expression, analysis and prediction of gene and protein structure and function, prediction and detection of gene regulation networks, simulation environments