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)
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1
Q

Where does photosynthesis take place? (1)

A

Chloroplasts

2
Q

What pigment do chloroplasts contain? (1)

A

Chlorophyll

3
Q

What does chlorophyll do? (2)

A
  • Absorbs sunlight
  • Uses its energy for photosyenthesis
4
Q

Word equation for photosynthesis? (2)

A

carbon dioxide + water —> glucose + oxygen

5
Q

Symbol equation for photosynthesis? (2)

A

6CO2 + 6H20 —> C6H12O6 + 6O2

6
Q

Label the parts {9)

A

1 - Waxy Cuticle

2 - Upper Epidermis

3 - Palisade

4 - Spongy Mesophyll

5 - Xylem

6 - Phloem

7 - Lower Epidermis

8 - Guard Cells

9 - Stoma

7
Q

Why are leaves broad? (1)

A
  • Large surface area exposed to light
8
Q

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

A
  • Palisade layer
  • So they are near the top of the leaf
  • To get the most light
9
Q

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

A
  • It is transparent
  • So light can pass through it to the palisade layer
10
Q

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

A
  • 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
Q

What is the role of the waxy cuticle (1)

A

reduces water loss by evaporation

12
Q

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

A
  • Stomata are little holes
  • Let CO2 diffuse directly into the leaf
13
Q

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

A
  • Light
  • Amount of CO2
  • Temperature of surrondings
14
Q

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

A
  • 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
Q

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

A
  • Because it is a raw material needed for photosyenthesis
  • Increasing conc of CO2 will increase rate of photosyenthesis up to a point
16
Q

Why does this curve flatten out (2)

A
  • Shows the amount of CO2 is not the limiting factor affecting photosyenthesis
  • Limiting factor is temperature or light intensity or both
17
Q

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

A
  • 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
Q

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

A
  • 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
Q

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

A
  • 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
Q

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

A
  • 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
Q

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

A
  • 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
Q

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

A

Starch

23
Q

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

A
  • 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
Q

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

A

deficiency symptoms

25
Q

Name the 4 mineral ions plants need (4)

A
  • Nitrates
  • Phosphates
  • Potassium
  • Magnesium (small amounts)
26
Q

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

A
  • 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
Q

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

A
  • Needed in small amounts
  • Required for making chlorophyll, needed for photosyenthesis
  • Plants without enough magnesium have yellow leaves
28
Q

Name the two main transport systems in plants (2)

A
  • Xylem
  • Phloem
29
Q

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

A
  • 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
Q

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

A
  • Vascular tissue
  • Carries water and mineral salts
  • From the roots to the leaves in the transpiration stream
31
Q

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

A
  • 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
Q

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

A
  • 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
Q

Draw a root hair cell and label it (5)

A
34
Q

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

A
  • Minerals (by active transport)
  • Water (by osmosis)
35
Q

What is transpiration (2)

A
  • Transpiration is the process of water movement through a plant
  • Caued by evaporation and diffusion of water from a plant’s surface
36
Q

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

A
  • 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
Q

What 4 factors affects the rate of transpiration (4)

A
  • Light intensity
  • Temperature
  • Wind Speed
  • Humidity
38
Q

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

A
  • Brighter the light, greater the transpiration rate
  • Stomata begins to close as it gets darker, meaning very little water can escape
39
Q

How does temperature affect the rate of transpiration (2)

A
  • 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
Q

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

A
  • 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
Q

How does humidity affect the rate of transpiration (4)

A
  • 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
Q

Describe an experiment to measure transpiration (9)

A
  • 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
Q

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

A
  • 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
Q

Experiement to show how temperature affects transpiration rate (2)

A
  • 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
Q

Experiement to show how humdity affects transpiration rate (3)

A
  • 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
Q

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

A
  • Use a fan
  • Increases wind speed
  • Increase the transpiration rate