<span>There are two major theories that will explain on research on colour vision. They are 1. the trichromatic theory also known as the Young-Helmholtz theory 2. opponent-process theory. These two theories explain processes that operate at different levels of the visual system.</span>
Answer:
The correct answer is - option B. They are small because they lack a nucleus.
Explanation:
Red blood cells or erythrocytes are specialized cell that produce in bone marrow and have specific role such as carrying oxygen from lungs to deliver it to the various organs and carry out carbon dioxide.
In mammals these cells lack cell organelles such as nucleus and mitochondria, a major factor that determined its smaller size. The size of RBC are move through narrow vessels throughout a organism because of its specific size and shape that provide it space for hemoglobin and allow to be flexible and bend to move through narrow vessels.
Thus, the correct answer is : option B. They are small because they lack a nucleus.
Answer:
While Americans constitute the 5% of the world population, they use around the 24% of the world's energy.
Then, if the 100% of the population were like the Americans, we have:
5%*x = 100%
x = 100%/5% = 20
the whole population is 20 times the population of the US, then the total energy used is 20 times the energy used in the US.
Then the energy that the 100% of the population would use is equal to:
20*24% = 480%
Sowe actually would need like 5 Earths.
So none of the options is matches this, but this may be because this question is about some specific resources and not for the specific energy used. The closest option is 200%
A is the answer to this question
Soil conservation involves protecting the soil layers and preventing erosion. Soil conservationists are very concerned with the topsoil, but take all layers into account.
