In which oceanic zone do clams and crabs survive by burrowing in the sand?

Mesopelagic zone

Explanation:

The Mesopelagic zone, also referred to as the Twilight zone, is the second oceanic zone from the top, lying just bellow the Epipelagic zone. It is occupying the waters at depths between 200 meters and 1,000 meters. The sunlight is only managing to reach the top few meters of this zone, while the rest is not receiving any sunlight, thus this zone is not supporting the plant species because they need sunlight for the process of photosynthesis. There are lot of animal species that live in this zone though, and they are ll very well adapted for it, often having hard shells or heavily scaled bodies, larger lungs and heart, and very well developed gills. Some of the animals that live in here are the crabs and the clams. They have developed all the needed characteristics to live in this zone. Because they are prey to lot of larger animals, both the crabs and the clams have started to use the soft sediments at the bottom as cover, digging themselves below it, and mostly managing to evade trouble and end up as food for the other species.

they fuse to form they have half as many chromosomes as a somatic cell of the same individual. b

question#1

ans:

cell is the basic unit of organization of all living things. cells are often called the building block of life and it is the smallest unit of life. the study of cell is called cell biology. cell consists of cytoplasm enclosed within membrane, which contain bio-molecules such as proteins and nucleic acid.

two third of cell is water, which means that two-third of your whole body is water. the rest is the mixture of molecules, mainly proteins, lipids and carbohydrates.

question#2

ans:

organ:

an organ is a group of tissues specialized to form a functional unit. an example is the heart in animals.

organ system:

an organ system is a group of several organs whose functions are synchronized to release an effective action in a living organism. an example is digestive system.

question#3

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#4

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#5

our body works because of the interactions that happen between organs and organ systems.  

for example:  

the heart to regulate blood flow throughout the body. the blood carries oxygen and nutrients to the cells and carries carbon dioxide and waste away from the cells. body systems work together in maintaining a constant internal environment. when this balance is disrupted, the body systems may not function properly, and human health can suffer.   you start to feel bad.