Plant Cell And Strucutre

Question 1

Describe cell wall

Answer 1

1. Ridged structure that surrounds and supports cell

2. Made of cellulose (beta glucose)

Question 2

Describe middle lamella

Answer 2

Gives stability

Question 3

Describe plasmodesmata

Answer 3

Channel in cell wall that allows transport of substances and communication between cells

Question 4

Describe pits

Answer 4

Regions where cell wall is very thin, arranged in pairs to allow transport of substances between cells

Question 5

Describe components of chloroplast

Answer 5

1. Flattened double membrane
2. Thylakoid arranged in stacks called grana
3. Grana linked by lamellae
4. Stroma

Question 6

Describe amyloplast

Answer 6

Membrane bound organelle containing starch grains

Question 7

Describe vacuole and tonoplast

Answer 7

Tonoplast= membrane controlling what leaves/ enters

Vacuole: cell sap, keeps cell turgid, breakdown of chemicals

Question 8

Describe xylem vessels

Answer 8

1. Transport water and mineral ions, provide support
2. No cytoplasm and no end walls so form tube structure
3. Found in bundles
4. Thickend by lignin
5. Substances move in/out through pits where no lignin

Question 9

Describe sclerenchyma fibres

Answer 9

1. Only provide support
2. Dead cells thickend with lignin
3. Don’t contain pits
4. Longer than they are wide and do have cell end walls

Question 10

What is the function of Phloem

Answer 10

Transport organic solutes from source to sink

This is translocation

Question 11

Describe Phloem

Answer 11

1. Not for support
2. Sieve tube elements joined end to end
3. Cell wall ends have holes in to allow solutes to pass
4. No nucleus, thin layer of cytoplasm
5. Rely on companion cells to carry out functions for both themselvs and sieve tube (provide energy for active transport)

Question 12

What do xylem vessels and phloem tissue do?

Answer 12

Group Into vascular bundles

Question 13

On a cross section, where is each component

Answer 13

Outer most: sclerenchyma
Middle: phloem tissue
Inner most: xylem

Question 14

What is the function of starch

Answer 14

Storage for excess glucose, broken down when need energy

Question 15

What are the two components of starch

Answer 15

1. Mixture of two polysaccharides of alpha glucose

2. Amylose and Amylopectin

Question 16

Describe the structure of Amylose

Answer 16

1. Unbranded chain of Alpha glucose
2. Coiled structure making it compact and good for storage
3. You can fit more in a small space

Question 17

Describe the structure of amylopectin

Answer 17

1. BRANCHED chain of alpha glucose
2. Side branches allow for enzymes to hydrolyse glycosidic bonds quickly
3. So energy quickly released

Question 18

Describe the properties of starch

Answer 18

1. Insoluble in water so doesn’t cause water to enter cell by osmosis
2. Good for storage

Question 19

Describe the structure of cellulose

Answer 19

1. Long, unbranched chain of beta glucose joined by 1,4 glycosidic bonds
2. Chains linked together by hydrogen bonds
3. To form strong threads called microfibrils
4. Strong so structural support

Question 20

How can plant fibres be useful for humans

Answer 20

Long tubes are very strong so can be used to make rope or fabric

Question 21

Describe how the arrangement of cellulose makes plant fibres strong

Answer 21

1. The cell wall contains cellulose microfibrils in a net-like arrangement
2. The strength of microfibrils and their arrangement gives plant fibres strength

Question 22

Describe how the secondary thickening of cell walls gives strength

Answer 22

1. When structural plant cells like xylem finish growing they produce a secondary cell wall
2. This is thicker and strengthen by lignin
3. Growth of this called secondary thickening

Question 23

Define tensile strength

Answer 23

Maximum load it can take before breaking

Question 24

Outline sustainability

Answer 24

Using renewable sources to meet needs of present gen without messing up planet

Question 25

Define renewable resources

Answer 25

1. Can be used indefinitely without running out 2. Such as plants that can be regrown 3. Without causing significant long-term damage

Question 26

Give an example of an unsustainable practice and a sustainable one

Answer 26

Sustainable: replacing a tree after cutting one down Unsustainable: using fossil fuels

Question 27

Explain how plant fibres can contribute to sustainability

Answer 27

1. Making rope and fabric (not out of plastic) 2. Less fossil fuel used up, regrown to maintain supply 3. Biodegradable by microbes 4. Cheaper and easier

Question 28

How can starch contribute to sustainability

Answer 28

1. Starch found in all plants, potatoes especially rich 2. Bioplastics made from starch rather than oil 3. More sustainable as less oil and crops can be regrown 4. Fuel called bioethanol made from starch