Cells know how to differentiate through a process called gene expression. It’s a specific combination of genes that are turned on and off.
<span>Human weight at the time of birth is influenced by stabilizing selection. Stabilizing selection, also known as negative selection, purifying selection or normalizing selection, is a type of natural selection in which genetic diversity decays according to a particular value of the character. This is the most common mechanism of action of natural selection.</span>
Answer:
D. By diffusion across a capillary wall
Explanation:
D is the best answer because gas exchange takes place in our lungs. Our lungs have alveoli which have a network of tiny blood vessels called capillaries, here the O2 diffuses the capillary wall to enter the bloodstream, and similarly CO2 diffuses out and we exhale it our from our lungs.
1. The energy left in the Quaternary consumer level is 0.06283 kcal.
2. 0.65 units of energy is still available at the tertiary consumer level.
<u>Explanation:</u>
Energy flow in an ecosystem obeys the ten percentage law According to which ten percentage of energy from a trophic level gets transferred to the next trophic level. In the given question plants belong to the trophic level , producers and it transfers 10 percentage of its energy to the primary consumer level.
In the question 1 the energy that the producers have is 628.3 kcal. Ten percentage of this i.e 62.83 kcal gets transferred to the primary consumer level. Ten percent of that which is 6.283 kcal gets transferred to the secondary consumer level. Ten percent of 6.283 kcal i.e 0.6283 kcal energy is transferred to the tertiary consumer level.
Thus the Quaternary consumer level gets ten percentage of 0.6283 kcal i.e 0.06283 kcal. In question B the initial energy at the primary level is 650 units. Ten percentage of 650 i.e 65 units reach the primary consumer level. Ten percentage of this 65 units then reaches the secondary consumer level. Thus the secondary consumer level has ten percent of 65 i.e 6.5 units of energy.
So the energy that reaches the tertiary consumer level is ten percentage of 6.5 i.e 0.65 units.