plant transport

Question 1

Define the term homeostasis

Answer 1

ability to maintain a constant stable internal environment

Question 2

suggest one reason homeostasis is important to plants

Answer 2

for metabolism or for enzyme activity

Question 3

explain the role of the cuticle in relation to homeostasis

Answer 3

prevent (reduce) water loss

Question 4

in which of the labelled parts is the rate of photosynthesis highest

Answer 4

palisade (cells), highest concentration of chloroplasts (chlorophyll)

Question 5

suggest two ways in which a leaf is well adapted for photosynthesis

Answer 5

large surface area / thin / presence of air spaces

Question 6

with regard to the stomata ,name
1. the gas
2. the cells which control their opening

Answer 6

1. C02 2. guard cells

Question 7

like the stomata, the lenticels also function in gaseous exchange. on what part of the plant are they located?

Answer 7

stem

Question 8

state one example of a plant which uses modified leads as a means of storing food

Answer 8

onion / daffodil / tulip / garlic

Question 9

by what process does water enter the root hairs

Answer 9

osmosis

Question 10

name two irish scientists who first described the upward movement of water in plants

Answer 10

Henry Dixon / John joly

Question 11

describe in detail the upward movement of water in plants

Answer 11

root pressure pushes water / in xylem / cohesion or water molecules stick together / continuous column /adhesion or water molecules tick to xylem walls

Question 12

give two structural differences between xylem and phloem

Answer 12

xylem has pits and phloem does not / xylem has lignin and phloem does not / phloem has companion cells and xylem does not / xylem has vessels or tracheids and phloem does not

Question 13

biuret

Answer 13

to test for protein

Question 14

Benedict’s solution

Answer 14

to test for reducing sugars

Question 15

why would you use a coverslip in relation to plants

Answer 15

to prevent cells from drying out or to protect the objective lens from water or from stain

Question 16

why do you apply methylene blue to the cells

Answer 16

to stain the cells or to make (the cells) easier to see

Question 17

name the vascular tissue through which the products of photosynthesis are transported in plants

Answer 17

phloem

Question 18

structural features of phloem

Answer 18

sieve tubes / companion cells / sieve plates

Question 19

what do you understand by the term turgor in plant cells

Answer 19

pressure of cell contents against the cell wall

Question 20

how do plant cells remain turgid for a considerable period of time

Answer 20

by taking in as water as they lose / by osmosis

Question 21

what happens to a plant if many of its cells lose turgidity

Answer 21

wilt or lose righty or droop

Question 22

explain how water enters root hairs and then passes to the vascular tissue

Answer 22

osmosis

Question 23

in which of the vascular tissues will water now rise through the plant

Answer 23

xylem

Question 24

give two features of xylem that facilates upward movement

Answer 24

narrow / continous tube (no end walls or open ended) / or pits / no cell contents /attraction of h20 to walls /thick walls

Question 25

name and briefly explain any two processes involved in upward movement of water in plants

Answer 25

root pressure, h20 in pushes h20 up

Question 26

suggest a way in which turgor is of value to plants

Answer 26

support

Question 27

name hte tissue inplant stems through which water rises to the leaves

Answer 27

xylem

Question 28

give one way in which xylem is adapted for the trasnport of water

Answer 28

narrow or continous lumen

Question 29

give a precise location of xylem in the tissue

Answer 29

in vascular bundles / next to phloem

Question 30

state another function for xylem

Answer 30

support or other transport function

Question 31

describe the principle features of the cohesion-tension model

Answer 31

water molecules stick together / due to h-bonding / continous chain of water molecules / water tends to adhere to xylem walls / transpiration or water loss pulls the column of water up

Question 32

the cohesion-tension model of transport attempts to explain water movement in plants against a particular force. Name this force

Answer 32

gravity

Question 34

In order to allow photosynthesis and other metabolic reactions to occur plants need to be able to acquire and transport

Answer 34

Water, oxygen, carbon dioxide and minerals

Question 35

What are the adaption of root hairs for absorption

Answer 35

Thin walls, not covered by cuticle and very numerous or large surface area

Question 36

How does water enter the cytoplasm of root hairs

Answer 36

By osmosis

Question 37

What does xylem transport

Answer 37

Water and materials

Question 38

What are the two types of upwards water movements in plants

Answer 38

Root pressure and transpiration

Question 39

Explain the term root pressure

Answer 39

As water is drawn into the roots by osmosis, the build up of water causes a pressure this root pressure pushes water up and through the xylem

Question 40

Explain transpiration

Answer 40

Transpiration is the loss of water by evaporation from the leaves and other aerial parts of the plant

Question 41

Where does transpiration take place

Answer 41

Most transpiration takes place through openings in the leaves called stomata

Question 42

What happens when the leaf cells lose water

Answer 42

They become less turgid and will wilt

Question 43

What helps the stomata reduce water lose

Answer 43

Guard cells

Question 44

Does diffusion require energy

Answer 44

No

Question 45

Does active transport require energy

Answer 45

Uses energy in form of atp

Question 46

How are roots modified so plants can store food

Answer 46

Some dicots produce large roots that penetrate into the soil, and absorb water or in some plants eg carrots the tap roots become swollen and fleshy with stored food

Question 47

How do modified stems allow plants to store food

Answer 47

Potato plants have underground stems that become swollen with stored starch

Question 48

How do modified leaves allow plants to store food

Answer 48

Onions,garlic and tulips produce bulbs a bulb contains an underground stem that is reduced in size, swollen fleshy leaves are modified to store food and are attached to to this stem

Question 49

What are lenticels

Answer 49

Lenticels are openings in the stems of plants that allow gas exchange

Question 50

What is the cohesion tension model

Answer 50

The cohesion tension model in plants explains how water can be transported to great heights in some plants against the force of gravity

Question 51

What is the main factor in the process of stomata opening and closing

Answer 51

The concentration of carbon dioxide in air spaces in leafs

Question 52

name the tissue in plant stems through which water rises tot he leaves

Answer 52

xylem

Question 53

give one way in which this tissue is adapted for the transport of water

Answer 53

narrow or continuous lumen

Question 54

give a precise location of this tissue in the stem

Answer 54

in vascular bundles

Question 55

state one function of xylem

Answer 55

support

Question 56

the cohesion tension model of transport attempts to explain water movement in plants against a particular force

Answer 56

gravity

Question 57

explain how water enters root hairs and then passes to the vascular tissue

Answer 57

cell to cell by osmosis, soil water more is more dilute

Question 58

name and briefly explain any two processes involved in the upwards movement of water in plants

Answer 58

root pressure : water in root pushes water up transpiration : water out pulls water up

Question 59

conditions for highest transpiration rate

Answer 59

hottest temperature or sunniest

Question 60

what is the advantage to plants having most of their stomata on the underside of the leaves

Answer 60

reduces water loss by transpiration

Question 61

what is the disadvantage to plants having most of their stomata on the underside of the leaves

Answer 61

wilting

Question 62

how do plants respond to wilting

Answer 62

close stomata / reduce stomata in size