plant form and function

Question 1

where are stomata found on a leaf

Answer 1

They are on the bottom because no direct sunlight, so less evaporation

Question 2

what are stomata and what are their functions

Answer 2

opening in plants that allows CO2 in and reduces water loss across their stomata

Question 3

how do plants reduce water loss across their stomata

Answer 3

When there isn’t enough water guard cells will close to reduce water loss.

Plants also have trichome which are hair like projections on the epidermis of the lead. They trap water droplets and this reduces transpiration

Question 4

what are the steps in the opening of the stoma?

Answer 4

1. when sunlight hits the leave it activates potassium ions to go into the stoma (through active transport so ATP is needed)
2. osmosis occurs, so also goes into the guard cells
3. reaches a limited epansion in length
4. so the guard cells start also bulging outwards

Question 5

how does the stoma close at night

Answer 5

diffusion of water and K+ ion out of the cell causes the guard cells to shrivel

Question 6

transpiration vs translocation

Answer 6

transpiration is the evaporation of water through leaves.

Translocation is the transportation of sugar in plants

Question 7

what is the function of phloem?

Answer 7

allows for rapid sucrose transport from leaves to stem and roots

Question 8

what is phloem made of?

Answer 8

sieve tubes that are living cells with perforated cross walls and no nucleus, ribosomes or cytoskeleton

Question 9

why do sieve tubes lack so much?

Answer 9

so it’s not blocking water and sugar

Question 10

describe companion cells and their function

Answer 10

have a nucleus and are next ot the sieve tube. give sugar to the sieve tube

Question 11

how does sucrose translocation occur?

Answer 11

sucrose is either pushed up or down depending on tugor pressure

Question 12

true or false. the plant expends its own energy for transpiration to occur

Answer 12

false. uses 0 of its own energy

Question 13

cohesion vs adhesion

Answer 13

cohesion is attraction between water mols

adhesion is water attraction to structures around them

Question 14

what are the steps of translocation?

Answer 14

1. active transport of sucrose from companion cell to sieve tube
2. sucrose diffusion across plamsodesmata
3. osmosis of water
4. tugor pressure increases.
5. sucrose pushed up or down

Question 15

what is transpiration

Answer 15

one way transfer of water and minerals when the plant expends o energy of its own. uses energy of sun as evaporation process

Question 16

where does transpiration occur

Answer 16

through dead xylem

Question 17

tracheid’s and vessels. explain the similarities and differences

Answer 17

the both transport water in all vascualr plants, but vessels are only found in flowering plants

Question 18

why are vessels better than tracheid’s

Answer 18

because they have no cross walls, so water goes through it easier

Question 19

a newly discovered plant has no stomata. Would you predict the plant to have a cuticle on the surface if its leaves? Why?

Answer 19

wouldn’t have a cuticle, so that it can breathe, but is more vulnerable to water loss

-NON-VASCULAR PLANTS DON’T HAVE CUTICLE

Question 20

which one would have greater adhesion: tracheid or vessels? why?

Answer 20

tracheids because it has more SA for adhesion

Question 21

what is meristem tissue?

Answer 21

tissue that consists of cells that are capable of growth throughout the life of a plant.

Question 22

what it a terminal bud and what is the advantage

Answer 22

meristem tissue found at the top of a plant. allows for growth in length.

Question 23

axillary buds description and advantage

Answer 23

(armpit of plant) meristem tissue on sides of plant.

Advantage: more SA for sun exposure, more photosynthesis; flower can come out of it and allow for sexual reproduction therefore more genetic variation

Question 24

what is root meristem and what is the advantage?

Answer 24

meristem tissue found in roots, increased absorption of water and minerls

more stability / mechaninal support
less likely to tip over in a storm

Question 25

why do some plants grow in width?

Answer 25

because of a cylinder of meristem tissue in between the xylem and phloem called vascular cambium

Question 26

do monocots have cambium?

Answer 26

no, they lost cambium; was in common ancestor of plants.

Question 27

how do growth rings form?

Answer 27

xylem has thick walls filled with ligning therefore keeps theri shape. growth ring represents a years woth of grouth, outer ring is newest because its next to cambium.

Question 28

what is the bark of a tree

Answer 28

dead phloem because phloem has thin cell walls they get squashed and die.

Question 29

how seasonal changes affect growth rings.

Answer 29

fires can cause scar tissure on inside of xylem. if growht is very wide means climate was ideal. lots of sunlight and water.

Allows us to know how much CO2 was in the air. Dark and light parts represent seasonal changes. Dark part is growth that happens in summer. Light is growth in the spring. Dark in summer because cells are more compact, less rain.

Question 30

What type of information is provided by growth
ring analysis?

Answer 30

ires can cause scar tissure on inside of xylem. if growht is very wide means climate was ideal. lots of sunlight and water.

Allows us to know how much CO2 was in the air. Dark and light parts represent seasonal changes. Dark part is growth that happens in summer. Light is growth in the spring. Dark in summer because cells are more compact, less rain.