The first day of last menstrual cycle.
Ultraviolet rays cause sun burns
Answer:
Evolution in nature by natural selection only modifies the structures present in the ancestors and favors the better adapted structures.
Explanation:
An engineer can design the bones and muscles of the forelimbs of given organisms as per their needs and give rise to new unique structures for each of these organisms.
On the other hand, evolution in nature allows the modification of existing traits by the accumulation of variations. The adaptive variations in the traits are then favored by natural selection. Therefore, forelimbs of mammals such as horses, whales, and bats have evolved by modification of the forelimbs present in their common ancestors.
The limitation of modification of existing structures does not allow the formation of a completely new structure.
Answer:
A. The ways that the continents fit together
Explanation:
hope it helps .
<span>8. Chitinase is an enzyme that breaks down the chitin molecules in an insect's exoskeleton. The sequence of amino acids in the chitinase is an example of which level of protein structure?
==> primary
9. The amount of energy needed for a reaction to take place is the activation energy. Enzymes can lower the activation energy of a chemical reaction. Which of the following describes a way that this could happen?
==> Molecules can be brought together so they will bond more easily.
10. What is one way that RNA differs from DNA?
==> It is single-stranded.
11. Which molecule do mammals use to store extra glucose in their muscles?
==> glycogen
12. Which molecule do plants use to store extra glucose?
==> starch
13. Which element is present in all amino acids, but not necessarily in fats or carbohydrates?
==> nitrogen
14. Which statement best describes the role of DNA in the body?
==> It contains genetic information.
15. Which statement best explains how enzymes speed up chemical reactions?
==> Enzymes lower the activation energy of a reaction.</span><span>
</span>
