B8 Plant Nutrition

Question 1

Why can you use a starch test as evidence that photosynthesis had been happening?

Answer 1

Starch is converted into glucose, glucose is a product of ohotosynthesis

Question 2

Chlorophyll

Answer 2

A green pigment needed for photosynthesis

Question 3

Why does a leaf need to be boiled before tested for starch?

Answer 3

The hot water kills the leaf and ‘opens’ the cells (breaks the cell membrane). It also allows for the ethanol to be absorbed

Question 4

Why does the leaf need to be put in ethanol before tested for starch?

Answer 4

Ethanol dissolves the chlorophyll and makes the leaf white. This makes it easier to test as you can see the blue black color better

Question 5

Adaptions of leaves to make them good at absorbing light

Hint there’s 6

Answer 5

1) The leaf stalks bend throughout the day - to get the most sunlight possible
2) leaves arranged in mosaic pattern - maximize sunlight absorption and surface area of sun contact
3) broad and flat leaves - increase surface area
4) mesophyll cells contain chlorophyll - light can penetrate the palisade mesophyll on sunny days
5) palisade mesophyll has the most chloroplasts - it’s closer to the surface so this maximizes photosynthesis
6) thin upper epidermis and transparent - easier gas exchange

Question 6

Adaptions of leaves to make them good at gas exchange

Hint there’s 3

Answer 6

1) thin leaves - easier gas exchange, faster diffusion
2) waxy cuticle penetrated by many stomata - to allow carbon dioxide and oxygen to pass in or out
3) air spaces between spongy mesophyll cells - air spaces are wet, allowing gases to dissolve and diffuse for easy gas exchange. Increase surface area for has exchange.

Question 7

Some adaptions that make leaves good at transport

Answer 7

Leaves have veins containing xylem and phloem - helps transport water and glucose

Question 8

Xylem

Answer 8

Transports water and minerals

Question 9

Phloem

Answer 9

Transports sugars

Question 10

Photosynthesis

Answer 10

The fundamental process in which plants manufacture carbohydrates from raw materials using energy from light

Question 11

Cuticle

Answer 11

The transparent layer on top of the leaf

Question 12

Upper epidermis

Answer 12

The single layer of flat cells covering the top surface of the leaf

Question 13

Palisade layer of cells

Answer 13

The layer of long cylindrical cells just under the upper epidermis

Question 14

Spongy mesophyll

Answer 14

The layer of cells with air-spaces between them

Question 15

Stomata

Answer 15

The pores on the underside of the leaf

Question 16

Guard cells

Answer 16

The cells that control the opening and closing of the stomatal pores

Question 17

Vascular bundle

Answer 17

The place that contains conducting tissues in the leaves

Question 18

Xylem

Answer 18

The ‘pipe’ that conducts water and minerals in the leaf

Question 19

Phloem

Answer 19

The ‘pipe’ that conducts food (sugar and glucose) in the leaf

Question 20

What do plants need to grow healthily?

Answer 20

water, carbon dioxide, light energy and small quantities of minerals

Question 21

Elements needed in plants

Answer 21

Nitrogen

Magnesium

Question 22

Nitrogen in plants

Answer 22

Mineral ions: nitrate and ammonium
These ions are needed by the plant so that it can convert the glucose made in photosynthesis into amino acids which are needed for making proteins. Proteins are needed for the growth of plants

Question 23

Magnesium in plants

Answer 23

Mineral ions: magnesium
These ions are needed in the manufacture of chlorophyll. Chlorophyll is needed to absorb light energy in the process of photosynthesis

Question 24

Pros of using fertilizers

Answer 24

1) they give nitrates to the soil to help the plants produce proteins and grow healthily.
2) allow farmers to grow crops close together and increase productivity

Question 25

Cons of using fertilizers

Answer 25

1) only half of fertilizers put on land is taken up by plants. The rest runs off and leaches into ground water and eventually rivers, ponds and lakes. Can cause eutrophication–> kills aquaitc life
2) gets into drinking water. Nitrate in water can cause “Blue baby syndrome” and cancer in stomach. It can also get into certain foods, e.g vegetables. Nitrate moves through soil very slowly and can be a problem even after 20 years
3) manufacturing them requires energy from fossil fuels–> pollution

Question 26

Eutrophication

Answer 26

When a body of water has a high abundance of nutrients and causes algae to grow on the surface.

Question 27

Word equation for photosynthesis

Answer 27

Carbon dioxide+ water –> glucose + oxygen

*sunlight above the –>

Question 28

Symbol equation for photosynthesis

Answer 28

6CO2 + 6H20–> C6H12O6 + 6O2

*chlorophyll/ light above –>

Question 29

Pigments

Answer 29

The colored substances in leaves that absorb light energy. The main pigment in leaves is chlorophyll