plant structures

Question 1

what is the word equation for photosynthesis

Answer 1

carbon dioxide+water=glucose+oxygen

Question 2

what is the balanced chemical equation for photosynthesis

Answer 2

6CO2+6H2O→C6H12O6+6O2.

Question 3

how does light affect rate of photosynthesis

Answer 3

as the light level increases, rate of photosynthesis also increases. after a certain point , rate of photosynthesis doesnt increase as CO2 or the temperature is a limiting factor

Question 4

how does CO2 have an affect on the rate of photosynthesis

Answer 4

as CO2 increases, rate of photosynthesis also increses. after a certian point, rate of photosynthesis doesnt increase as light level or the temperature is a limiting factor

Question 5

how does temperature have an affect on the rate of photosynthesis

Answer 5

increasing temp will increase rate of photosynthesis upto a certain point. after that, enzymes will become denatured

Question 6

what are some adaptations of root hairs

Answer 6

they have root hair cell which will increase the surface area so it can absorb more water and mineral ions

Question 7

what are phloem tubes

Answer 7

-tubes made of living cells
-does translocation
-it has end walls

Question 8

what do phloem tubes mainly transport

Answer 8

sucrose

Question 9

what are xylem tubes

Answer 9

-made of dead cells
-does transpiration
-it has no end walls

Question 10

what doe xylem tubes mainly transport

Answer 10

water and mineral ions

Question 11

what is the process of transpiration

Answer 11

-this is the loss of water from the plant
-the plant loses a small amount of water so more water will then be absorbed
-this water will be absorbed in the roots and will be transported throughout the plant via xylem tubes

Question 12

what is stomata and why is it used

Answer 12

these are tiny pores on the surface of a plant. they allow CO2 to diffuse in and oxygen to diffuse out of the plant

Question 13

how does the stomata open

Answer 13

guard cells become swollen with water (turgid) which will open the stomata

Question 14

how does the stomata close

Answer 14

water in the guard cells will evaporate which means that the guard cells become flaccid.

Question 15

what is the palisade layer in leaves

Answer 15

this layer has lots of chloroplasts. they are near the top of the leaf so they can get the most light

Question 16

what is the upper epidermis in the leaves

Answer 16

this is a transparent layer above the palisade layer so the light can pass through it and get absorbed in the palisade layer

Question 17

what is a waxy cuticle in the leaves

Answer 17

it is a layer at the surface of the leaf and it helps to reduce water loss

Question 18

what is the spongy mesophyll in the leaves

Answer 18

this contains lots of airspaces which will increase the rate of diffusion of gases

Question 19

what is the lower epidermis in the leaves

Answer 19

this is found at the bottom of the leaf and it contains lots of stomata

Question 20

how are plants in the desert adapted

Answer 20

-thick waxy cuticles: to reduce water loss by evaporation
-small leaves or spines: reduces surface area for water loss
-fewer stomatas: reduces water loss

Question 21

what are auxins

Answer 21

they are plant growth hormones and they control growth at the shoots and roots

Question 22

how are shoots positively phototrophic

Answer 22

auxins build up in the side which is shade from the son. this makes the cells on the shaded side grow faster so the shoot will then grow towards the light

Question 23

how are shoots negatively gravitrophic

Answer 23

auxins build up on the lower side of shoot due to gravity. this makes the lower side grow faster, making it grow upwards

Question 24

how are roots positively gravitrophic

Answer 24

auxins build up in the lower side of the root. but in the roots, more auxins means less growth. so, the top side of the roots grow faster making it grow downwards

Question 25

how are roots negatively phototrophic

Answer 25

auxins build up on the shaded side of the root. in the roots, more auxins mean less growth. this means the upper half will grow faster making it grow downwards

Question 26

how do you use plant hormones to produce seedless fruit?

Answer 26

applying gibberellins to unpollinated flowers means that the fruits will grow without seeds

Question 27

how can plant hormones be used to control seed germination

Answer 27

seeds dont germinate unless they have been through certain conditions. but if they are treated with gibberellins, they can germinate in conditions they normally dont

Question 28

how can plant hormones be used to control the ripening of fruit

Answer 28

if you add ethene to the fruit, it will ripen on the way to the market

Question 29

how are plant hormones used to grow plants from cuttings?

Answer 29

if you add rooting powder, which contains auxins, it will grow rapidly.

Question 30

how are plant hormones used as selective weedkillers

Answer 30

weeds are broadleaved. selective weedkillers have auxins which only affect broad leaved plants

Question 31

how are plant hormones used to control flower and fruit formation

Answer 31

gibberellins stimulate seed germination. they can be used to make plants flower earlier or in conditions they dont usually flower