Deoxyribonucleic acid (DNA) is the hereditary material that lies within the nucleus of all cells in humans and other living organisms. Most of the DNA is placed within the nucleus and is called nuclear DNA.
A chromosome is made up of two chromatids which are joined by the centromere. The chromatids separate from each other during mitosis to form two new chromosomes. The DNA making up a chromosome is dispersed as chromatin.
Under a microscope, chromatids look like little dots and chromosomes are lines.
Answer:
Ribosomes, Cell membrane
Explanation:
Ribosomes can be described as structures which are involved in the production of proteins. Ribosomes are hence known to be the protein manufacturing units of a cell. As enzymes are also proteins,they will be synthesized in the ribosomes.
Cell membrane can be described as the membrane which is present outside the cell or which separates the cell from the external environment.
For an enzyme to pass through the external environment, it will have to pass through the ribosomes and the cell membrane.
Answer:
1. Sexual Reproduction
2. Genetic variations
Explanation:
Human reproduces through sexual reproduction. Sexual reproduction is the process of production of new progeny by the formation of male and female gametes (sperms and egg respectively) and fusion of gametes. During gamete formation, crossing over adds new gene combinations to the gametes. The genetic variations make the progeny of sexual reproduction different from each other and from the parents.
Chewing a saltine cracker is a physical change
