Cells

Question 1

What is the nucleus involved in?

Answer 1

• controls normal cell activities
• responsible for cell reproduction
• repairs worn-out parts of the cell

Question 2

What does the nucelus contain?

Answer 2

• instructions for protein synthesis
• the organism’s genetic material

Question 3

What happens when a cell does not have a nucleus?

Answer 3

• the cell will have a shorter lifespan e.g. red blood cell
• reproduction is not possible

Question 4

What takes place in the cytoplasm?

Answer 4

• most life processes take place
• chemical reactions take place e.g. metabolism

Question 5

What is the job of the cell surface membrane?

Answer 5

• regulates the movement of substances in and out of the cell

Question 6

What cannot enter the cell and why?

Answer 6

• large molecules such as proteins, carbohydrates and lipids
• they cannot enter as they are too large to enter the cell
• things that do not dissolve in lipids (fats) e.g. water
• charged molecules e.g. ions

Question 7

What can enter the cell and why?

Answer 7

• small molecules such as oxygen and carbon dioxide
• they are small enough to easily diffuse into the cell
• things that dissolve in lipids (fats)

Question 8

How do substances that dissolve in water enter the cell?

Answer 8

• proteins become channels for small molecules that dissolve in water

Question 9

What is the cell surface membrane made up of?

Answer 9

• it is made up of lipids and proteins

Question 10

What is the purpose of the cell wall?

Answer 10

• to provide shape and support to the cell

Question 11

Why can all things pass through the cell wall?

Answer 11

• it is fully permeable

Question 12

What are some characteristics of the cell wall?

Answer 12

• they are rigid and distinct
• they enclose the whole cell
• they are made up of cellulose

Question 13

What do chloroplasts do?

Answer 13

• to trap light
• to combine carbon dioxide and water to make food

Question 14

What are chloroplasts?

Answer 14

• they are the site of photosynthesis

Question 15

What does the mitochondrion do?

Answer 15

• it is involved in cellular respiration
• they are also involved in the release of energy from food

Question 16

What does the mitochondria synthesize?

Answer 16

• adenosine triphosphate (atp)

Question 17

What is the endoplasmic reticulum?

Answer 17

• it is an extension of nuclear membrane into cytoplasm
• it is a network of membranes
• there are two types of endoplasmic reticulum (ER)
• rough and smooth ER

Question 18

What does the smooth ER do?

Answer 18

• synthesizes lipids, cholesterol and steroids
• converts harmful substances into harmless ones
• this process is called detoxification

Question 19

What does the rough ER have and what does it do?

Answer 19

• it has ribosomes
• ribosomes attached produce proteins for secretion outside the cell

Question 20

What do free lying ribosomes do?

Answer 20

• they produce proteins for use inside the cell

Question 21

What is the golgi body?

Answer 21

• series/stack of membrane-bound sacs

Question 22

What does the golgi body do?

Answer 22

• modifies products from the ER and secretes them (secretory vesicles)

Question 23

What is the difference between the vacuole of an plant cell and that of an animal cell?

Answer 23

• animal cells have many small vacuoles that are usually not permanent
• plant cells have a large, central vacuole

Question 24

Why is there a difference in the vacuole of a plant cell and animal cell?

Answer 24

• animals are able to replenish their water supply regularly
• plants need to go long periods of time without water so their vacuoles need to store more water for long periods of time

Question 25

What is the function of a root hair cell?

Answer 25

• absorbing water and mineral salts from soil

Question 26

What is the adaptation in the root hair cell and why is it useful?

Answer 26

• narrow and long protrusion
• to increase surface area of cell

Question 27

What is the result of the adaptation of the root hair cell?

Answer 27

• efficient absorption of water and mineral salts from soil

Question 28

If adaptation of root hair cell was missing?

Answer 28

• plant wilts
• plant becomes unhealthy and susceptible to diseases

Question 29

What is the function of red blood cell?

Answer 29

• transport oxygen from lungs to all parts of the body

Question 30

What is the adaptation of the red blood cell?

Answer 30

• circular
• biconcave
• contains hemoglobin
• does not have a nucleus

Question 31

What is the result of adaptation of red blood cell?

Answer 31

• diffusion rate of oxygen in and out of cell increases
• more oxygen carried per cell
• increases surface area to volume ratio

Question 32

What would happen is the adaptation of the red blood cell was missing

Answer 32

• lack of oxygen in cells
• cellular respiration affected

Question 33

Phrases associated with each structure

Answer 33

• nucleus: double membrane, contains many enzymes
• cell membrane: single membrane, partially permeable, transport
• mitochondria: double membrane, respiration, contains many enzymes
• chloroplasts: double membrane, pigmented, photosynthesis, contains many enzymes
• rough endoplasmic reticulum: single membrane, ribosomes, protein synthesis
• cell wall: non living, permeable, support
• large central vacuole: support, cell sap, storage, single membrane
• smooth endoplasmic reticulum: single membrane, lipid synthesis
• red blood cell: pigmented, transport
• xylem vessel: non living, transport, support
• root hair cell: absorption