Answer:
Option (D)
Explanation:
The Paleozoic Era refers to the time, from about 540 million years ago to 250 million years ago. During this era, there occurred drastic changes on earth. was a time of great change on Earth.
Life first originated in water, and with time the evolutionary process occurred and gave rise to the formation of numerous varieties of living species that dwelled in both the land as well as in water.
During this Paleozoic era, the primitive aquatic plants appeared, which were gradually widely spread over the large seas and oceans. There also occurred marine organisms such as trilobites, for the first time during the Cambrian period of the Paleozoic era. By the Ordovician period, these aquatic plants and animals were abundant, due to which it was commonly referred to as the age of aquatic plants and animals.
By the end of this era, there occurred a heavy mass extinction event, that wiped out almost 75-80% of all the living species on earth.
The Paleozoic era most aptly describes the metamorphic rocks as mot of the metamorphic rocks found on earth belongs to this era.
Thus, the correct answer is option (D).
Answer:
Coevolution.
Explanation:
Coevolution may be defined as the process of evolution of two species together. The coevolution was first coined by Peter H. Raven and Paul R. Ehrlich.
The co evolution effects the evolution of the species and reciprocally effect each other. For example: the insect and the flowering plant both evolve with each other and may sometime develop the mutual relationship each other.
Thus, the correct answer is option (b).
Not to be too picky, but the question ought to say a positively charge ion rather than atom.
I will assume that is what you mean. An ion, using ordinary means, will be positive if it loses electrons (which are negative).
An ion can never gain protons. Left alone, the nucleus will remain unchanged for the rest of eternity. D is wrong.
C is wrong. If electrons are gained, the ion will go negative.
B is wrong for the same reason D is. An ion can't gain protons and it can't lose them.
A is the answer.
Cells are found in everything on the earth.
See it as matter, matter is everywhere. Everywhere or anything you look at is matter.
A compound consists of two or more elements.
