B2 - plants

Question 1

what does having a large surface area do?

Answer 1

maximises absorption of light; for optimum absorption of carbon dioxide

Question 2

what does having A thin, flattened blade do

Answer 2

So that water and gases have a limited distance to diffuse

Question 3

why do some plants have Vascular tissue in the midrib and veins

Answer 3

Branches of the xylem, to transport water and minerals to the leaf; branches of the phloem, to transport glucose and other products of photosynthesis to other parts of the plant

Question 4

why do some plants have Air spaces between cells within the leaf

Answer 4

For the diffusion of gases

Question 5

Q: What are the two types of transport systems in plants?

Answer 5

A: Xylem and Phloem

Question 6

Q: What does the xylem transport in plants?

Answer 6

A: Water and minerals

Question 7

Q: What does the phloem transport in plants?

Answer 7

A: Sugars and amino acids dissolved in water

Question 8

Q: How are the xylem and phloem distributed in the root?

Answer 8

A: The xylem forms a central column for support, and the phloem is outside the xylem.

Question 9

Q: How are the xylem and phloem arranged in the stem?

Answer 9

A: They are grouped into vascular bundles.

Question 10

Q: What is the main organ of photosynthesis in plants?

Answer 10

A: The leaves

Question 11

Q: What is the function of the palisade mesophyll in leaves?

Answer 11

A: It absorbs light efficiently for photosynthesis.

Question 12

Q: What are the characteristics of the palisade mesophyll cells?

Answer 12

A: They are packed with chloroplasts, column-shaped, and arranged closely towards the upper surface of the leaf.

Question 13

Q: What is the function of the spongy mesophyll in leaves?

Answer 13

A: It allows for efficient gas exchange.

Question 14

Q: How do gases enter the leaf for photosynthesis?

Answer 14

A: Through small pores called stomata.

Question 15

Q: What process causes water to be lost from the leaf?

Answer 15

A: Transpiration

Question 16

Q: What is transpiration?

Answer 16

A: The process where water evaporates from the leaf, leading to the movement of water through the plant.

Question 17

Q: What is the role of xylem in plant transport?

Answer 17

A: It transports water and minerals from the roots to the leaves.

Question 18

Q: What are vessels in the xylem?

Answer 18

A: Specialised cells that lose their end walls to form a continuous, hollow tube.

Question 19

Q: What is lignin and what does it do?

Answer 19

A: Lignin strengthens and supports the plant by strengthening the xylem cells.

Question 20

Q: What is the process of transport in the phloem called?

Answer 20

A: Translocation

Question 21

Q: What substances does the phloem transport?

Answer 21

A: Food substances like sugars and amino acids produced by photosynthesis.

Question 22

Q: What are sieve tubes in the phloem?

Answer 22

A: Specialised cells for transport that have no nuclei and perforated ends to allow cytoplasm flow.

Question 23

Q: What are companion cells in the phloem?

Answer 23

A: Cells that provide energy for the transport in sieve tubes.

Question 24

Q: What is diffusion and how does it relate to plants?

Answer 24

A: Diffusion is the movement of substances from an area of high concentration to low concentration. It helps smaller plants like mosses take in substances.

Question 25

Q: What is osmosis? `

Answer 25

A: The movement of water from an area of higher water potential to lower water potential across a semi-permeable membrane.

Question 26

Q: What happens during transpiration?

Answer 26

A: Water evaporates from the leaf surface, and a continuous column of water is drawn up through the xylem to replace it.

Question 27

Q: What is the purpose of transpiration?

Answer 27

A: It provides water for photosynthesis, transports mineral ions, cools the leaf, and keeps cells turgid.

Question 28

Q: What are root hairs and what is their function?

Answer 28

A: Single-celled extensions of epidermal cells that absorb water and minerals from the soil.

Question 29

Q: How does water enter root hair cells?

Answer 29

A: By osmosis, as the soil water has a higher water potential than the root hair cell cytoplasm.

Question 30

Q: How do minerals enter root hair cells?

Answer 30

A: By active transport.

Question 31

Q: What factors affect the rate of transpiration?

Answer 31

A: Temperature, humidity, air movement, and light intensity.

Question 32

what is epidermal

Answer 32

type of plant tissue that covers the surface of a plant

Question 33

pallisade mesophyll

Answer 33

tissye in the leaf where photosynthesis takes place

Question 34

spongey mesophyll

Answer 34

tissue in the leaf with air spaces betweem cells

Question 35

xylem

Answer 35

narrow tubes in the roots stems and leaves which transport water and mineral ions up from the root

Question 36

pholem

Answer 36

other tubes that run up along the xylem but carry dissolved sugars instead.

Question 37

meristem

Answer 37

type of tissue found at growing tips of roots and shoots containing stem cells so they can differentiate into different sorts of plant cells

Question 38

guard cell

Answer 38

In pairs guard cells form the stoma on leaves - the holes through which gases are exchanged, they can open and close the stoma as required by a plant.

Question 39

comparison of transport i the xylem and pholem

Answer 39

Xylem physcial process transports water and minerals transports upwards phloem requires energy transports Products of photosynthesis; includes sugars and amino acids dissolved in water transports Upwards and downwards

Question 40

does temprature increase or decrease transporation rate

Answer 40

Increases An increase in temperature increases evaporation, so the rate of diffusion of water from inside the leaf to outside increases

Question 41

does humidity increase or decrease transporation rate

Answer 41

Decreases A decrease in humidity reduces the concentration of water molecules outside the leaf, so the rate of diffusion of water from inside the leaf to outside increases

Question 42

does air movement increae or decrease transporation rates

Answer 42

Increases An increase in air movement removes water vapour from outside the leaf, so the rate of diffusion of water from inside the leaf to outside increases

Question 43

does light intensity increase or decrease transporation rates

Answer 43

Increases An increase in light intensity generally increases the number of open stomata, so the rate of diffusion of water from inside the leaf to outside increases