Answer AND Explanation:
<u>FACTORS THAT CAUSE GENETIC VARIATIONS</u>
- Crossing over. At the chiasmata during prophase I of meiosis, breakage may occur and exchange of genetic information may take place. New gene combinations which result in variations.
- Independent assortment. The arrangement of homologous chromosomes at the equator of the spindle during metaphase of the first meiotic division is random. These homologous chromosomes segregate into different daughter cells which contain different genetic combinations which brings about variation
- Fertilisation permits parental genes to be brought together in different combinations. This is the cause of variations in members of the same family.
- Mutation is the spontaneous change in the genetic makeup of an organism. These changes may be inherited by the offspring therefore beginning variation.
This is a process called transcription and translation.
Information to synthesize a particular protein is found in DNA in the cell nucleus. This information is copied (transcribed) onto messenger RNA or mRNA in short. The copying process is called transcription.
mRNA then leaves the nucleus and enters the cytoplasm where it attaches to a ribosome. Transfer RNA or tRNA then begins to read (translate) the information on the attached mRNA. This is the process of translation.
tRNA then fetches amino acids that correspond to this information and brings them to the ribosome where they are linked together into a chain. This chain of amino acids is the primary structure of the protein.
The organisms in a pond and the physical factors <span>influencing them best describe "an ecosystem" since this is a self-contained environment will multiple organisms. </span>
