He is incorrect because a catalyst is a substance that speeds up a chemical reaction so if there is no reaction to begin with a catalyst will not due anything.
Explanation:
members of the same species battle each other to protect their young
When your body temperature rises because of an infection, it's called a fever<span>. </span>Fevers<span> are caused by chemicals called pyrogens flowing in the bloodstream. Pyrogens make their way to the hypothalamus in the brain, which is in charge of regulating body temperature.</span>
The right answer is C. I think, a. and d. are obviously not serious. B is not true, because Ag and Au are in the same group in the periodic table and therefore have the same number of electrons in the last level. So, they form ions with the same charge. C is true beacause Ag and Au have different numbers in the periodic table and different amount of protons and neutrons in their nucleuses.
The production of egg and sperm cells follows a certain sequence of events.
The correct order of those events are:
MEIOSIS, CELL DIFFERENTIATION, MATURE GAMETES.
Meiosis is defined as the process wherein a single cell is divided twice to produce four cells that contains half the original amount of genetic information.
Cell differentiation is defined as the process wherein the less specialized cell becomes a more specialized cell. The haploid cells are the end result of meiosis. They must undergo cell differentiation before they can become mature gametes.