The human body - cells - ch 3

Question 1

How many cells in the human body?

Answer 1

100 trillion

Question 2

Are these cells visible to the eye?

Answer 2

No

Question 3

What is the cell surrounded by?

Answer 3

membranes

Question 4

Describe the function of a membrane?

Answer 4

1. Holds the contents of the cell together
2. Identifies the type of cell to other cells to selectively allow substances, such as those produced by the body or drugs introduced into it to pass into and out of the interior of the cell.

Question 5

Name two major parts of a cell?

Answer 5

cytoplasm and nucleus

Question 6

What does cytoplasm consist of?

Answer 6

1. mainly of water
2. Enzymes
3. Salts
4. Organelles such as mitochondria and ribosomes and certain organic molecules.

Question 7

What are the principal acitivities of cytoplasm?

Answer 7

1. To dissolve waste created by the cell
2. Move materials around inside the cell
3. Permits the cells to carry out their specialised functions such as transmitting impulses or storing fats and is therefore vital to effective functioning of the human body.

Question 8

What are the various organelles such as mitochondria responsible for?

Answer 8

Maintenance of the cells

Question 9

What is the role of the mitochondria in the cytoplasm?

Answer 9

Cellular respiration which generates energy to enable the cell to function.

Question 10

Name the series of channels in the cytoplasm?

Answer 10

endoplasmic reticulum

Question 11

What is the role of endoplasmic?

Answer 11

The synthesis, folding, alteration and transport of proteins

Question 12

What is the role of the nucleus cell?

Answer 12

To act as the centre for administration and information and regulates activities of the cell.

Question 13

Name the materials in a human nucleus?

Answer 13

Chromosomes (deoxyribonnucleic acid or DNA)

Question 14

Whats the role of a chromosome?

Answer 14

To control cell growth and reproduction

Question 15

How many chromosomes are in each cell?

Answer 15

46, 23 matched pairs except for the egg cells in the female and sperm cells in the male.

Question 16

How many female egg cells and male sperm cell chromosomes are there at time of conception?

Answer 16

23 chromosomes each

Question 17

What is the role of the large amount of genes contained in the chromosomes?

Answer 17

1. Genes contain information about the composition of particular cells in the body to instruct them to grow in a certain way.
2. Genes pass inherited materials to offspring corresponding to various biological traits.

Question 18

Give 3 examples of heriditary traits?

Answer 18

Blood type, hair and eye colour

Question 19

What is it called if something goes wrong with a gene or the way it behaves?

Answer 19

Mutation

Question 20

Can a mutation cause defects or illnesses in the body?

Answer 20

Yes

Question 21

If a mutation exists in an ovum or a sperm cell or both can it be passed on or inherited by a child

Answer 21

Yes

Question 22

Can diseases occur due to a defect in a single gene or in a set of genes?

Answer 22

Both