Topic 6: Plant Structures and Their Functions

Question 1

explain how photosynthesis contributes to a plant’s biomass

Answer 1

1. photosynthesis gives glucose

2. the glucose is used to make larger complex molecules which contributes to the biomass.

Question 2

is photosynthesis endothermic or exothermic!

Answer 2

endothermicy

endothermic reactions is a reaction that takes in heat

Question 3

what is the word equation for photosynthesis?

Answer 3

carbon dioxide + water → glucose + oxygen

Light and chlorophyll above arrow

Question 4

where inside the cell does photosynthesis happen

Answer 4

chloroplasty

Question 5

what does chloroplast contain

and what does this dooo

Answer 5

it contains chlorophyll

chlorophyll absorbs light

Question 6

what are the 3 limitations to photosynthesis

Answer 6

1. carbon dioxide concentration
2. light intensity
3. temperature

Question 7

which one limiting factor if it is too much will affect the rate of photosynthesis

and why

Answer 7

temperature

because if it is too hot the enzyme will get denatured and will not be able to fit the substrate.

Question 8

at what temperature do plant enzymes get denatured

Answer 8

45 degrees celsius

Question 9

what is ze effect of temperature on photosynthesis!

Answer 9

LOW temp → LOW rate of photosynthesis
HIGH temp (45C +) → NO photosynthesis (enzymes denatured)

Question 10

what is the effect of light intensity on photosynthesis

Answer 10

LOW light → LOW rate of photosynthesis

Question 11

what is ze effect of CO2 concentration on photosynthesis

Answer 11

LOW CO2 → LOW rate of photosynthesis

Question 12

explain the interactions between the 3 limiting factors

Answer 12

once a limiting factor has reached its peak (except heat ) the rate of photosynthesis depends on the other two limiting factors.

Question 13

what is the relationship between light intensity and distance from the light source.

Answer 13

they are inversely proportional

light intensity decreases in proportion to SQUARE of distance ( inverse square law )

Question 14

what is the formula for light intensity

Answer 14

light intensity = 1/d^2

units for light intensity: arbitrary units

Question 15

what is the equation for photosynthesis

Answer 15

6CO2 + 6H20 → C6H12O6 +6O2

Question 16

explain how the structure of the root cells is adapted to absorb water and mineral ions from the soil

Answer 16

each root cell has millions of microscopic root hair cells which give it a higher surface area for absorption

Question 17

how are mineral ions transported into the root hair cell

Answer 17

active transport

Question 18

how is water transported into the root hair cell

Answer 18

osmosis

Question 19

what cells are phloem tubes made up of

Answer 19

elongated living cells

with small pores in end walls

Question 20

what do phloem tubes transport

Answer 20

food aka sucrose

Question 21

where in the plant is sucrose made

Answer 21

in the leaf via photosynthesis

Question 22

what are the 2 destinations of sucrose flowing through the phloem

Answer 22

immediate use

or stoooorage

Question 23

what do xylem tubes transport

Answer 23

water and mineral ions

Question 24

what cells are xylem tubes made up off

Answer 24

dead cells
joined end to end no end walls

Xed out like dead lol

Question 25

what is a xylem tube strengthened by

Answer 25

lignin (glue)

Question 26

what is the movement of water up a plant called

Answer 26

transpiration stream

Question 27

what is the movement of sucrose through the plant called

Answer 27

translocation stream

Question 28

where does the water move from and to in the transpiration stream

Answer 28

``` soil root hair cell via osmosis xylem leaves evaporation ```

Question 29

what is the difference between the direction between the phloem and the xylem

Answer 29

``` phlOem = bOth directions (up and down) xYlem= xY to the skY (up only) ```

Question 30

what causes the transpiration stream to be ongoing

Answer 30

the constant evaporation of water from the leaves makes 3shtana so water is constantly being drawn up to replace it

Question 31

selective weed killers

Answer 31

weed killers have been developed from auxins which will only affect the broad leaved plants eventually killing them by disrupting their normal growth

Question 32

growing from cuttings with root powder

Answer 32

adding rooting powder to a cutting it contains auxins which will produce roots rapidly and start to grow as a new plant

Question 33

producing seedless fruit

Answer 33

if gibberelins are applied to unpollinated flowers of some plants the fruits will grow but the seeds wont

Question 34

controlling seed germination

Answer 34

lots of seeds wont germinate till they have been through certain conditions. seeds can be given gibberelins so that they can germinate at any time of the year that they wouldnt normally.