Answer:
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions.
Step-by- step-Explanation:
- Archaebacteria are very similar to Bacteria with respect to their cell size,prokaryotic organisation,circular DNA etc.
- Archaebacteria very similar to Gram-positive bacteria on the basis of cell structure.
- Both bacteria and Archaebacteria have several similar Metabolic Pathways.
- Unlike Bacteria Archaebacteria are habitants of extreme climates like hot springs and ice capped continents.
Thus Archaebacteria are much alike to Eubacteria.
Answer:
The behavior of chromosomes during meiosis and fertilization is responsible for most of the variation that arises in each generation. Three mechanisms contribute to genetic variation arising from sexual reproduction: independent assortment of chromosomes, crossing over, and random fertilization.
Because mostly some microorganism may be very small and harmful that can affect humans or animals just by the experience of the microorganism.