chapter 2 - organization and maintenance of the organism

Question 1

*state the function of the cytoplasm in plant and animal cells:

Answer 1

where many chemical reactions take place, which keep the cell alive, by providing energy and making substances the cell needs.

Question 2

*state the function of the nucleus in plant and animal cells:

Answer 2

1- controls the type and quantity of enzymes produced by the cytoplasm.
2- determines what the cell will be.
3- regulates chemical changes which take place in the cell.
4- controls cell division.
5- contains genetic material (DNA), which determines how the cell will grow an work.

Question 3

*state the function of the cell membrane in plant and animal cells:

Answer 3

1- stops cell contents from escaping.
2- controls what substances enter and leave the cell.
3- maintains the structure and chemical reactions of the cytoplasm.

Question 4

*state the function of the cell wall in plant cells:

Answer 4

1- made of cellulose which makes it tough and so prevents the cell from bursting.
2- not selective like the cell membrane, it allows water and dissolved substances to pass through.
3- under a microscope, cells appear to be sharing the same cell wall.

Question 5

*state the function of vacuoles in plant cells:

Answer 5

1- stores food.

2- makes the cell firm and turgid.

Question 6

*state the function of chloroplasts in plant cells:

Answer 6

absorb light energy for photosynthesis.

Question 7

what is the function of ribosomes?

Answer 7

*present in the cytoplasm of both plants and animal cells.

protein synthesis.

Question 8

what is the function of endoplasmic reticulum?

Answer 8

*present in the cytoplasm of both plants and animal cells.
Rough ER are flattened cavities which carry ribosomes.
produce, store and transport proteins.
*all cells except prokaryotes have ER.

Question 9

*what is the function of mitochondria?

Answer 9

• present in the cytoplasm of both plants and animal cells.
• produce energy from food substances by aerobic respiration.
• cells with higher rates of metabolism require large numbers of mitochondria to provide sufficient energy.
• all cells except prokaryotes have mitochondria.

Question 10

*describe the structure of ciliated cells:

Answer 10

extension of the cytoplasm at the surface of the cell forms tiny hairs called cilia which are in a continuous flicking motion.

Question 11

*what is the function of ciliated cells:

Answer 11

movement of mucus in the trachea and bronchi.