They protect the skin from attacks by predators, parasites and other injuries.
The answer is lipids.
<span>The macromolecules with the highest number of carbon-hydrogen (C-H) bonds are the lipids. The one of the main functions of the lipids is energy storage, therefore, they contain many C-H bonds which contain potential energy. Although carbohydrates can also store energy, they contain much oxygen .
So, he will need mostly black and red balls for a model of lipids.</span>
Transpiration is the process in which moisture is carried through plants from roots to little pores on the bottom of leaves, where it changes to vapor and is discharged to the atmosphere<span>.
</span>Leaf surfaces are dotted with pores called stomata.<span> It is a tiny opening or pore that is used for gas exchange. They are mostly found on the under-surface of plant leaves.</span>
Answer:
A zygote is the union of the sperm cell and the egg cell . Also known as a fertilized ovum, the zygote begins as a single cell but divides rapidly in the days following fertilization. After this two-week period of cell division, the zygote eventually becomes an embryo.
Explanation:
Answer:
The correct answer is A.
Explanation:
Diffusion is the net movement of a substance from a region of higher concentration to a region of lower concentration. The difference in concentration between two environments creates a concentration gradient which is what drives diffusion. Therefore, this movement does not require aid such as extra energy molecules for active transport or integral membrane proteins for directed movement, hence the answer is not B nor C. If the cell is in equilibrium with its environment, it means that the concentration of substances inside the cell is equal to the concentration outside the cell, and any movement that takes place will be random movement of substances across the plasma memberane. Movement in the cell will not cease as the cell is still active. Therefore, the answer cannot be D either.
