Answer:
Chromosomes are systemized structures of proteins and DNA. It have a string like shape, mainly located within the nucleus of both plant and animal cells. DNA is concentrated in the chromosomes. In 1902, Sutton and Boveri proposed that chromosomes has a part in heredity opposing Mendel's theory of segregation and independent assortment.
One major function of the chromosome is to keep the DNA from being altered or negatively influenced during cell division. It ensures accurate distribution of the DNA during the breaking down of genetic material. In mitosis, the chromosomes are duplicated and dispersed to daughter cells so that each cell attains a diploid set of chromosomes totally of the same nature to that of its parent cell. In meiosis, the resultant cells would attain a chromosome from each chromosome pair this will lead to half the number of chromosomes. This process is important for the offspring being produced to have the same characteristics of the parents which would results from the fusion of the sperm and egg of the parents.
The earthworm has a closed circulatory system, and there are 3 main vessels: <span>aortic arches, dorsal blood vessels, and ventral blood vessels.
aortic arches: It functions as the heart of the earthworm
dorsal blood vessels: Responsible to carry blood to the front of the body
ventral blood vessels: Responsible to carry blood to the back of the body
hope this helps</span>
