Answer:
The answer is A
By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
Answer:
If an organism has a beneficial trait, they have a higher chance of survival, and if they can survive they can reproduce too.
Example: Speckled moths camouflage with the bark of trees and are not easily seen by predators. Black moths do not camouflage with the bark of trees and are easily seen by predators, therefore the black moths are eaten. Because the black moths have been eaten they cannot reproduce and pass on the trait for black wings to their offspring, but the speckled moths are able to reproduce because they survived and are able to pass on the speckled wing trait to their offspring.
There are four main types of tissue: muscle, epithelial, connective and nervous. Each is made of specialized cells that are grouped together according to structure and function. Muscle is found throughout the body and even includes organs such as the heart. Our outer layer of skin is epithelial tissue.
DNA structure. DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C).
