There are a few different types of cell-cell interactions. Some of these interactions are meant for big molecules that enter and exit the cell called, endocytosis (entering the cell) and exocytosis (exiting the cell). For smaller particles like amino acids, water, ions and other solutes there are different types of direct contact between the cells called gap junctions.
The leaves are green in color due to the presence of chlorophyll pigment in them. These pigments are responsible for food making process in plants known as photosynthesis.
The organelle in the plant cell that is the site of photosynthesis and contains chlorophyll pigment is called CHLOROPLAST.
Chloroplasts are found in the plants and contain DNA like mitochondria. These are also the site of ATP production.
Answer:
If a whole specie of organisms has to survive, they should must possess the ability to reproduce and adopt to environmental conditions in better way.
For example: If a disaster occurs or a condition of unfavorable weather occurs, the specie will survive even if only few members remain alive. Because those members will reproduce and regrow the community.
The reason is this that reproduction is not important for the survival of one organism, like organism will still survive even if he do not reproduce, but if a whole specie has to survive and continue, reproduction is most important trait.
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D. They transport oxygen to all the cells of the body