When it is said that mutation is the ultimate source of genetic variation it means that it creates several new combinations which is similar to meiosis and fertilization because <span> new alleles and genes appear. It is just about some common points.</span>
Ans.
Cell-to-cell communication allows signalling of essential substances between the plant cells, which are surrounded by cell walls. The molecules used by plants for long-distance signalling are known as hormones, such as auxin, ethylene, and gibberelin.
These hormones are secreted by one plant cell and received by another plant cell, where it exerts it affect. Thus, the correct answer to be fill in the blank is 'option A). hormones.'
Answer:
a. amount of a pesticide that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace.
Explanation:
Pesticides are chemical substances used to get rid of or kill pests that attack crops on farmlands. These pesticides, although help the farmer to get rid of his pest problem and likely have an increase in yield, are dangerous to human and animal health if consumed.
As set up by the Environmental Protection Agency (EPA), pesticide tolerance is the amount or quantity of pesticide chemical that can be applied to a food and how much of the pesticide that is permitted to remain on the food in the marketplace.