2.5 The ultrastructure of plant cells

Question 1

Plant cells, unlike animal cells, are what?

Answer 1

rigid structures

Question 2

What make plant cells rigid structures?

Answer 2

they had a cell wall surrounding the cell-surface membrane

Question 3

Plant cell walls are made of what?

Answer 3

cellulose, a complex carbohydrate

Question 4

Cell walls are what so that substances can pass into and out of the cell?

Answer 4

freely permaable

Question 5

The cell walls of a plant cell gives the cell its what?

Answer 5

shape

Question 6

What makes a plant cell rigid?

Answer 6

The contents of the cell press against the cell wall

Question 7

What does the rigidity of the plant do?

Answer 7

support both the individual cell and the plant as a whole

Question 8

The cell wall, other than making the cell rigid, acts as a what?

Answer 8

a defence mechanism, protecting the cointents of the cell against invading pathogens

Question 9

Not all plant cells have cellulose cell walls. True or false

Answer 9

False

Question 10

What are vacuoules?

Answer 10

membrane lined sacs in the cyotoplasm containing cell sap

Question 11

What do vacuoules contain?

Answer 11

cell sap

Question 12

Many plant cells have large permanent vacuole which are very important for what?

Answer 12

the maintenance of turgor, so that the contents of the cell push against the cell wall and maintain a rigid framework for the cell

Question 13

What is the result of the maintenance of the turgor from large permanent vacuoles

Answer 13

the contents of the cell are pushed against the cell wall and maintains a rigid framework for the cell

Question 14

The membrane of a vacuoule is called the what?

Answer 14

tonoplast

Question 15

The membrane of a vacuoule is what kind of permeable and why?

Answer 15

selectively- some small molecules can pass through it but others cannot

Question 16

If vacuoules appear in animal cells, describe them

Answer 16

they are samll and transient (not permanent)

Question 17

What are chloroplasts responsible for?

Answer 17

photosynthesis in plant cells

Question 18

Where are chloroplasts found

Answer 18

in the green parts of the plant

-leaves stems but not in roots

Question 19

What kind of structure does chloroplasts have?

Answer 19

double membrane structure (similar to mitochondria)

Question 20

What is the stroma in chloroplasts?

Answer 20

the fluid enclosed in the chloroplast

Question 21

What contains the chlorophyll pigments

Answer 21

the grana (several thylakoids stacked together)

Question 22

Chloroplasts also have an internal network of what and what do they do?

Answer 22

network of membranes, which form flatted sacs called thylakoids

Question 23

several thylakoids stacked together are called?

Answer 23

granum (plural grana)

Question 24

the grana are joined by?

Answer 24

membranes called lamellae

Question 25

starch produced by photosynthesis is present as?

Answer 25

starch grains (found inside chloroplast)

Question 26

like mitochondria, chloroplasts also contain..

Answer 26

DNA and ribosomes

Question 27

Chloroplasts and mitochondria have their own DNA and ribosomes, so therefore are able to?

Answer 27

make their own proteins

Question 28

The internal membranes of chloroplasts provide what?

Answer 28

the large surface area needed for the enzymes, proteins and pigment molecules necessary in the process of photosynthesis

Question 29

2a) Many different oganisms have cell walls including fungi and bacteria. What is unique about plant cell walls?

Answer 29

-plant cell walls contain cellulose

Question 30

2b) Give three functions of plant cell walls

Answer 30

• prevent cells bursting
• allows turgidity
• idea that keeps plants upright
• protects content of cells from invading pathogens

Question 31

3) Describe the similarities and differences between a human cell and a plant root cell

Answer 31

• Both have a nucleus, cell surface membrane, mitochondria, ribosomes, golgi body, endoplasmic reticulum
• only plants have chloroplase, cell wall and large (central vacuoules)
• centrioles present in animal cells not not flowering plants