Section 3 - Plant Nutrition and Transport Flashcards Preview

Edexcel GCSE Biology > Section 3 - Plant Nutrition and Transport > Flashcards

Flashcards in Section 3 - Plant Nutrition and Transport Deck (46)
Loading flashcards...
1

Where does photosynthesis take place? (1)

Chloroplasts

2

What pigment do chloroplasts contain? (1)

Chlorophyll

3

What does chlorophyll do? (2)

- Absorbs sunlight

- Uses its energy for photosyenthesis

4

Word equation for photosynthesis? (2)

carbon dioxide + water ---> glucose + oxygen

5

Symbol equation for photosynthesis? (2)

6CO2 + 6H20 ---> C6H12O6 + 6O2

6

Label the parts {9)

1 - Waxy Cuticle

2 - Upper Epidermis

3 - Palisade

4 - Spongy Mesophyll

5 - Xylem

6 - Phloem

7 - Lower Epidermis

8 - Guard Cells

9 - Stoma

7

Why are leaves broad? (1)

- Large surface area exposed to light

8

Where are most chloroplasts found in a leaf and why? (3)

- Palisade layer

- So they are near the top of the leaf

- To get the most light

9

How is the upper epidermis adapted for efficent photosyenthesis (2)

- It is transparent

- So light can pass through it to the palisade layer

10

Why do leaves have a network of vascular bundles (4)

- These are the transport vessels xylem and phloem

- They deliver water and other nutriets to every part of the leaf

- They take away the glucose produced by photosyenthesis

- Help to support the leaf structure

11

What is the role of the waxy cuticle (1)

reduces water loss by evaporation

12

What are stomata and how do they make gas exchange/photosyenthesis more efficent (2)

- Stomata are little holes

- Let CO2 diffuse directly into the leaf

13

Name 3 factors affecting a plant's rate of photosyenthesis (3)

- Light

- Amount of CO2

- Temperature of surrondings

14

Why does not enough light slow down the rate of photosyenthesis (3)

- Chlorophyll uses light energy to perform photosyenthesis

- It can only do it as quickly as the light energy is arriving

- If light intensity is increased, rate of photosyenthesis will steadily increase, up to a point

15

Why does too little carbon dioxide slow down photosyenthesis (2)

- Because it is a raw material needed for photosyenthesis

- Increasing conc of CO2 will increase rate of photosyenthesis up to a point

16

Why does this curve flatten out (2)

- Shows the amount of CO2 is not the limiting factor affecting photosyenthesis

- Limiting factor is temperature or light intensity or both

17

Describe the graph; how temperature affects rate of photosyenthesis (3)

- As the temperature increases, so does the rate of photosyenthesis, up to a point

- If the tempeature goes above roughly 45 degrees, enzymes will denature

- This means the rate of photosyenthesis rapidly decreases

18

Describe how to test a leaf for Starch? (5)

- Kill it by dunking it in boiling water (hold with tweezers)

- Put leaf in a boiling tube with ethanol 

- Heat the tube in a water bath (gets rid of chlorophyll)

- Rinse the leaf in cold water and add a few drops of iodine

- If starch is present, leaf will go blue-black

19

Describe an experiement to show chlorophyll is needed for photosyenthesis (5)

- Use a variegated leaf that's been exposed to light 

- Record which parts are green and which aren't (green parts contain chlorophyll)

- Test the leaf for starch (see other flashcard)

- Only the Green parts will turn blue-black

- Shows only parts that contained chlorophyll could photosyenthesise and produce starch

20

Describe an experiement to show CO2 is needed for photosyenthesis (5)

- Use a soda lime, sealed bell jar, plant and light source

- Soda lime will absorb CO2 out of the air in the jar

- Leave the plant for a day

- Test leaves for starch, won't turn blue/black

- Shows no starch has been made in the leaf, means that CO2 is needed for photosyenthesis 

21

Describe an experiement to show light is needed for photosyenthesis (4)

- Grow a plant without any light, e.g in a cupboard

- Cut a leaf and test for starch (see other flashcard)

- The leaf won't turn blue/black, no starch present

- Shows light is needed for photosyenthesis, as no starch has been made

22

If a plant can't photosyenthesise, it can't produce ..... (1)

Starch

23

Describe an experiment to measure the effect of light intensity on the rate of photosyenthesis (7)

- Use canadian pondweed

- Faster it produces oxygen, faster the rate of photosyenthesis

- Source of white light is placed 30cm away from the pondweed

- Leave pondweed to photosyenthesise for 2 minutes

- Count no. of bubbles produced

- Control temperature, time

- Repeat with light source, 40cm, 50cm, 60cm and 70cm

24

If there aren't enough mineral ions in the soil, plants suffer .............. ............

deficiency symptoms

25

Name the 4 mineral ions plants need (4)

- Nitrates

- Phosphates

- Potassium

- Magnesium (small amounts)

26

Why do plants need nitrates and what happens if there is a deficency (3)

- Nitrates contain nitrogen for making amino acids and protein

- These are needed for cell growth

- If a plant can't get enough; it will be stunted and will have yellow older leaves

27

Why do plants need magnesium and what happens if there is a deficency (3)

- Needed in small amounts

- Required for making chlorophyll, needed for photosyenthesis

- Plants without enough magnesium have yellow leaves

28

Name the two main transport systems in plants (2)

- Xylem

- Phloem

29

Why do plants and animals need transport systems to move substances around their bodies but unicellular don't (4)

- Unicellular, substances can diffuse directly in and out across the cell membrane

- Diffusion rate is quick because of the short distances

- Multicellular, direct diffusion is too slow, large distances

- So multicellular need transport systems to move substances quickly

30

What is the xylem and what does it transport (3)

- Vascular tissue

- Carries water and mineral salts

- From the roots to the leaves in the transpiration stream

 

31

What is the phloem and what does it transport (4)

- Vascular tissue

- Transports amino acids, surcrose and other sugars

- From where they are made in the leaves to other parts of the plant

- By translocation

32

How are root hairs adapted to absorbing water from soil (3)

- Millions of microscropic hairs on each branch of a root

- Gives the plant a big surface area for absorbing water from the soil

- By osmomis

33

Draw a root hair cell and label it (5)

34

Outline 2 substances taken in by root hair cells (2)

- Minerals (by active transport)

- Water (by osmosis)

35

What is transpiration (2)

- Transpiration is the process of water movement through a plant

- Caued by evaporation and diffusion of water from a plant's surface

36

Explain how transpiration helps a plant lose/obtain water (6)

- Transpiration is caused by the evaporation and diffusion of water from a plant's surface

- Most transpiration happens at the leaves

- Water escaping from the leaves through the stomata by diffusion causes a slight shortage of water in the leaf

- More water is drawn up from the rest of the plant through the xylem to replace it

- Means more water is drawn up from the roots

- Constant transpiraton stream of water through the plant

37

What 4 factors affects the rate of transpiration (4)

- Light intensity

- Temperature

- Wind Speed 

- Humidity

38

How does light intensity affect the rate of transpiration (2)

- Brighter the light, greater the transpiration rate

- Stomata begins to close as it gets darker, meaning very little water can escape

39

How does temperature affect the rate of transpiration (2)

- The warmer it is, the faster transpiration happens

- When it's warm, water particles have more energy to evaporate and diffuse out of the stomata

40

How does wind speed affect the rate of transpiration (3)

- The higher the wind speed, the greater the transpiration rate

- If it's windy, water vapour is swept away, maintating a low conc of water in the air outside the leaf

- Therefore diffusion happens faster, inreasing the transpiration rate

41

How does humidity affect the rate of transpiration (4)

- The drier the air around a leaf, the faster transpiration happens

- If the air is humid, diffusion happens slower

- This is because there's a lot of water in the air, making less of a difference between the inside and outside of a leaf

- Diffusion (and therefore transpiration) happens faster with a high conc in one place, and a low conc in the other

42

Describe an experiment to measure transpiration (9)

- Use a potometer to estimate transpiration rate

- Cut a shoot underwater to prevent air from entering the xylem

- Cut it at a slant to increase surface area for water uptake

- Insert the shoot underwater, so no air can enter

- Remove apparatus from water, but keep the end of a capillary tube submerged in a beaker of water, watertight and airtight

- Dry the leaves, shut the tap

- Remove the end of the capillary tube from the beaker of water until one air bubble has formed, then put it back into water

- Start a stopwatch and measure distance moved by the bubble per hour

- Keep conditions constant, e.g temperature and humidity

 

43

Experiement to show how light intensity affects transpiration rate (3)

- Use previous experiment as a control, vary light intensity and compare results

- Use a lamp to increase the intensity of light that hits the plant; this should increase the transpiration rate

- To decrease the light intensity, put the potometer in a cupboard, decreasing transpiration rate

44

Experiement to show how temperature affects transpiration rate (2)

- Vary temperature by putting the potometer in a room that's warmer or colder than the control experiement room

- An increase in temperature should increase rate of transpiration, a decrease should lower it.

45

Experiement to show how humdity affects transpiration rate (3)

- Increase humiditiy of air around the plant

- By spraying water in a clear plastic bag before sealing it around the plant

- Should decrease the rate of transpiration

46

Experiement to show how wind speed affects transpiration rate (3)

- Use a fan

- Increases wind speed

- Increase the transpiration rate