Answer:
A food chain is a representation of what eats what in an ecosystem.
A combination of food chains is termed as a food web.
Example of two food chains in a food web are :
Example No 1:
Plant----- Grasshopper------ Frog---snake--- bacteria
Example No 2:
Plant---- rabbits---- fox---- bacteria
In a food chain, producers are usually plants and algae which are able to make their own food. Consumers feed on the plants. In example no 1, grasshoppers are primary consumers, frogs are secondary consumers, snakes are tertiary consumers.
In example no 2,plants are producers, rabbits are primary consumers and foxed are secondary consumers.
Decomposers are organisms that feed on the dead organisms in a food chain. In both the examples of food chain, bacteria are the decomposers.
The two differences you see when comparing the four chambers of the heart is that the arteries have a thicker wall and veins have thin walls and that the arteries carry oxygenated blood away from the heart which means they get more pressure than veins.
Answer: population
hope this helped
Answer:
a. heart development.
Explanation:
As the third week of fetal development starts, the process of formation of blood vessels begins. Also, the splanchnic mesoderm in the head end of the embryo forms heart on days 18 and 19. Since it develops heart, this part of the mesodermal cells is called the cardiogenic area. The underlying endoderm sends the induction signals to these mesodermal cells to form a pair of endocardial tubes that gradually develop into a single primitive heart tube.
This primitive heart begins to beat by the end of the third week of development. Therefore, any drug that affects fetal development during the first 20 days of the pregnancy might affect the development of the heart.
