model answers of chapter 2

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1-complete the following:

2-what the function of:

it gives the plant extra support and protection.
it traps the sunlight to help the plant to make its food through photosynthesis,also it gives the plant its green colour.
when it is very hot the sweat evaporates taking the heat away leaving the body cold.
it carries oxygen to all body cells.
if protect the body as it keep grems & dirts away,also it prevent too much water to be evaporated.
it supports the body,it help the movement of the body as muscles are attached to the bones {the skeletal system}, also it protects important organs such as THE SKULL protect the BRAIN, THE RIBS protect the HEART & LUNGS.
in movment
it transmits nerve signals from the brain and the spinal cord to all body parts for coordination.

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3-give the reason for:

as it is the source of energy by breaking down the food which is made by phtotsynthesis & combining it with oxygen in the mitochondria.
as plant cell contain cell wall & chloroplasts which are not found in the animal cell.
as they work together to move the body.
through the release of SWEAT as when it evaporates it takes the heat awy leaving the body cold.
as the nucleus is the control center of the cell ,it contains the chromosomes which carry all the instructions for the cell.
as they join to overlap to cover the surface of the body.
which give it extra surface area to be able to carry more oxygen to the cells.
as the tissue is made up from similar cells that have the same function that work together to perform a certain function.
they support the body,they help with muscles in movment of the body,bones protect important organs as the brain & the heart ,the ribs.
due to the presence of large amount of calcuim in the bones.

4- state (t) or (f) & then correct the wrong answer:

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5-DEFINE:

cilia is hair like structure cell that is located in the trachea of the respiratory system to sweep dirts and germs away from entering the body.
it islocated in the inner ear,when it vibrates it bends to transmits signals to the brain.
it is where hairs are formed ,,hairs hold the warm next to your body.
these fibers are made up of protiens that when move s make sthe whole cell shorter.
it is a stiff hard memebrane surrounding the plant cell only which give it more support and protection.
DNA is a coiled twistted ladder structure inside the nucleus of the cell.it is formed from chromosomes that carry all the instructions of the cell.the DNA makes the genes where each gene carry a unit information about the cell.