4.2.3.1 Plant Tissues

Question 1

What is organisation like in plants?

Answer 1

• Cells are the basic units of life
• Groups of the same type of cells work together to form tissues
• Groups of tissues work together to form organs
• The root, stem and leaves form a plant organ system that transports substances in and around plants
• The whole plant is an organism

Question 2

Function of Plant Organs: Flower

Answer 2

• Attracts pollinators
• Involved in reproduction

Question 3

Function of Plant Organs: Stem

Answer 3

• Supports plant - contains thickened material called lignin
• Contains vessels for transport of nutrients in plants

Question 4

Function of Plant Organs: Leaf

Answer 4

Contains pigment chlorophyll in chloroplasts to carry out photosynthesis to make food for the plant

Question 5

Function of Plant Organs: Root

Answer 5

• Anchors plants in soil
• Absorbs and stores nutrients

Question 6

Where is meristematic tissue found in plants?

Answer 6

Found at thetips of roots and shootsand around the vascular tissue in stems

Question 7

What are meristems?

Answer 7

Groups ofundifferentiatedstem cells that divide to produceallthedifferent types of cells that make up a plant

Question 8

How long are plants capable of producing new tissue?

Answer 8

• Throughout its life
• Unlike animal cells

Question 9

What can plants that are resistant to disease do?

Answer 9

Can be quickly and economically cloned using their meristematic tissue

Question 10

How can rare plants be protected from extinction?

Answer 10

• Can be cloned
• Use seed banks

Question 11

Apical meristem:

Answer 11

• Causes primary growth i.e. lengthening of the plant
• Occurs at tips of roots and shoots
• Produces new leaves and flowers

Question 12

Lateral meristems:

Answer 12

• Causes secondary growth i.e. widening of the plant
• Occurs at the cambium
• Produces bark on trees

Question 13

Layers of a leaf/leaf tissue: Waxy cuticle

Answer 13

Waxy substance and reduces water loss from evaporation

Question 14

Layers of a leaf/leaf tissue: Upper epidermis

Answer 14

• Thin and transparent to allow light to pass through
• Has no chloroplasts stopping it from blocking light
• Prevents water loss by evaporation
• Any damage to the outer layer may not damage photosynthesising cells

Question 15

Layers of a leaf/leaf tissue: Palisade mesophyll

Answer 15

• Regular shaped cells packed with chloroplasts
• 80% of photosynthesis takes place here
• Max absorption of light for photosynthesis

Question 16

Layers of a leaf/leaf tissue: Spongy mesophyll

Answer 16

• Irregular shaped cells to increase the surface area for gas exchange
• Air spaces, stomata
• Some chloroplasts
• 20% of photosynthesis takes place here

Question 17

Layers of a leaf/leaf tissue: Lower epidermis

Answer 17

CO2 diffuses into these cells and is exchanged with O2 during the day

Question 18

Guard cells:

Answer 18

• cells swell and open the stomata
• control gas exchange and water loss of the plant

Question 19

Stomata:

Answer 19

open and close to allow gas exchange and water loss of the plant within the environment

Question 20

What are all the layers of a leaf/plant tissue?

Answer 20

• Waxy cuticle
• Upper epidermis
• Palisade mesophyll
• Spongy mesophyll
• Lower epidermis
• Meristem tissue

Question 21

Layers of a leaf/leaf tissue: Meristem tissue

Answer 21

• Found at the tips of the roots and shoots
• Stem cells found here (unspecialised cells) go through mitosis to increase length of plant

Question 22

Diagram to show the layers of a plant:

Answer 22