Answer: Option A) Oxygen may not have been able to accumulate in the atmosphere
Explanation:
Ozone, O3, is an allotrope of oxygen having three atoms in the molecule instead of the usual two present in molecular oxygen. Ozone is generated from oxygen, and is the only form in which oxygen can exist in the atmosphere.
The mutation must occur in the egg cell
Answer B burning fossil fuels in vehicles, power stations, and factories
Explanation:
Answer: it’s fertilization
Explanation: Fertilization in flowering plants happens through a process called pollination. ... Fertilization occurs when one of the sperm cells fuses with the egg inside of an ovule. After fertilization occurs, each ovule develops into a seed. • Each seed contains a tiny, undeveloped plant called an embryo.
Answer:
A) They form chemical bonds with other atoms
Explanation:
In chemistry, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.