Plant tissues organs and structures

Question 1

3 examples of plant organs

Answer 1

stems, roots, leaves

Question 2

what do plant organs work together to make

Answer 2

plant organ systems

Question 3

purpose of organ systems

Answer 3

transporting substances

Question 4

list 5 main tissues that make up a leaf

Answer 4

1.Epidermal tissue
2. Palisade Mesophyll tissue
3. Spongy Mesophyll tissue
4. Xylem & Phloem
5. Meristem tissue

Question 5

describe what epidermis tissue is made of

Answer 5

Thin outer layer of flattened cells. Covered with a waxy cuticle to reduce water loss

Question 6

describe the function of upper epidermis

Answer 6

Transparent and at the very top of the leaf to absorb sunlight for photosynthesis

Question 7

3 main function/description of palisade mesophyll tissues

Answer 7

.Layer of cylindrical cells
. Lots of chloroplasts
.Main site of photosynthesis

Question 8

3 main function/description of spongy mesophyll tissues

Answer 8

.Layer of rounded cells
.contains chloroplasts
. lots of air space for gas exchange

Question 9

Where is the meristem tissue found and what is its purpose

Answer 9

Found on root & shoot tips.
Differentiates by mitosis into different plant cells
Lots of stem cells
helps the plant grow

Question 10

Characteristics and function of Phloem vessels

Answer 10

.made of columns of elongated LIVING cells
.transports sucrose/other minerals (from phototsynthesis) from leaves to entire plant
. Transports both up and down

Question 11

Characteristics and function of Xylem vessels

Answer 11

.made of DEAD cells joined end to end
. runs from roots up to the stem and leaves
.Strengthened through Lignin
. Carries water and dissolved minerals
. ONLY transports upwards

Question 12

Structural Differences between Xylem and Phloem 4

Answer 12

Xylem- dead elongated cells
Phloem- alive elongated cells

Xylem- no cytoplasm
Phloem- small cytoplasm

Xylem- cells firm a continuous tube
Phloem- cells connected via sieve plates

Xylem- wall reinforced with lignin
Phloem- no reinforcement

Question 13

How are guard cells adapted to open and close stomata when the plant has lots of water

Answer 13

. guard cells go turgid
. cell swells causing the stomata to open so gases can be exchanged for photosynthesis

Question 14

How are guard cells adapted to open and close stomata when the plant is short of water

Answer 14

. Guard cell goes flaccid
. causes stomata to close
. helps stop water vapour from escaping
.reduces gas exchange

Question 15

2 ways guard cells reduce water loss

Answer 15

Guard cells are light sensitive so close at night
.Found in the undersides of leaves so it is shaded and cooler

Question 16

define transpiration stream
what occurs in the leaves

Answer 16

the constant movement of water through the xylem from roots to leaves,
where evaporation then occurs through stomata

Question 17

define translocation

Answer 17

the movement of dissolved sugars made in the leaves to the rest of the plant

Question 18

what is transpiration caused by

Answer 18

the evaporation and diffusion of water vapour

Question 19

how does the transpiration (loss of water) cause a constant transpiration stream

Answer 19

.creates a water shortage on the leaves so more water is drawn up from the roots .there is a constant transpiration stream through the xylem vessels

Question 20

transpiration is a side effect of what

Answer 20

the stomata during gas exchange

Question 21

what and why is gas exchange needed

Answer 21

oxygen and carbon dioxide is needed for the process of aerobic respiration and photosynthesis.

Question 22

how does water diffuse out the plant
(diffusion gradient)

Answer 22

because there is more water inside the plant then in the air outside

Question 23

4 main ways that effects the transpiration rate

Answer 23

light intensity
temperature
water availability/ humidity
air flow

Question 24

how does light intensity affect the transpiration rate (opening and closing) of stomata

Answer 24

.Brighter the light, greater transpiration rate
.stomata closes when it gets dark because there is no light therefore very little water escapes

Question 25

how does temperature affect the transpiration rate (opening and closing) of stomata

Answer 25

. warmer it is, faster transpiration rate . warm means the water particles have more KE to evaporate/diffuse out the stomata

Question 26

how does water availability/humidity affect the transpiration rate (opening and closing) of stomata

Answer 26

humidity -. drier the air, faster the transpiration rate water availability- diffusion happens faster when there is more high concentration in the leaf compared to the surroundings .lack of water causes guard cells to turn flaccid so the stomata closes. .

Question 27

how does air flow affect the transpiration rate (opening and closing) of stomata

Answer 27

the stronger the winds, greater transpiration rate

Question 28

Starting from the roots what’s the first method of transpiration

Answer 28

Water gets absorbed by osmosis intro the root hair cell

Question 29

Second method from transpiration (through the xylem)

Answer 29

Water molecules pull other water molecules in a continuous column of water up the xylem

Question 30

Third method of transpiration (xylem to leaf)

Answer 30

Water will move by osmosis from the xylem into the leaf cells

Question 31

Forth/fifth method of transpiration

Answer 31

The water evaporates from the cells Water vapour leaves through stomata This creates a concentration gradient because there is more water in the xylem then in the leaf cells

Question 32

what does a potometer do

Answer 32

Measure the rate of transpiration by measuring the uptake of water because (the water uptake is directly related to the water loss- transpiration)

Question 33

As a first step to measure transpiration why was the root cut at a slant underwarter

Answer 33

To ensue the xylem vessel is water filled and to avoid air bubbles Larger surface area so more water uptake

Question 34

What is applied to the joints of the plant shoot when inserted into the potometer? And why

Answer 34

Vaseline, to make sure the setup is airtight and to prevent air from entering.

Question 35

How does water move through the capillary tube in a potometer?

Answer 35

As the plant transpires, water is pulled up through the xylem, causing an air bubble to move along the capillary tube.

Question 36

What measurements are recorded in a potometer experiment?

Answer 36

The starting position of the air bubble and the distance it moves over time.

Question 37

How is the rate of water uptake calculated in a potometer experiment?

Answer 37

Using the formula: rate = volume of water uptake / time (e.g., mm³/min).

Question 38

What is the aim of the practical (leaves on a washing line)

Answer 38

To investigate water loss from leaves by transpiration

Question 39

Why are leaves hung on a washing line

Answer 39

To allow air to circulate all the leaves equally for a fair testing

Question 40

What is the dependent variable in this experiment (washing line)

Answer 40

The mass of each leaf over time

Question 41

How is water loss calculated

Answer 41

By finding the percentage mass loss

Question 42

Which treated leaf is expected to have the greatest mass loss and why (Vaseline)

Answer 42

The leaf with no Vaseline applied Because the stomata is not blocked allowing constant transpiration Water evaporates and is lost into the air

Question 43

A leaf has Vaseline only applied to it’s upper surface what change in mass is expected

Answer 43

The leaf will still lose water, similar results to the untreated leaf However it will be less wilted then the untreated Most stomata are on the lower surface so transpiration still occurs

Question 44

What are the expected results of a leaf with both surface covered with vaseline

Answer 44

The leaf would lose very little water Both surfaces are covered therefore all the stomata are blocked preventing transpiration So no water loss Any water loss would be due to exposed parts on the leaf

Question 45

Expected results of a leaf with the lower surface covered (Vaseline)

Answer 45

Similar percentage mass loss to the leaf with both sides treated Blocks majority of stomata on lower surface

Question 46

Why is it important to compare percentage mass loss rather than just mass loss by each leaf

Answer 46

Because each leaf may have different starting masses Therefore percentage loss takes Ina count the starting mass as well the final so it is more accurate comparing.

Question 47

Some potential errors in this experiment (washing line)

Answer 47

Variation in leaf size/shape Uneven Vaseline layer Environmental variation e.g. humid

Question 48

What is the aim of the stomata imprints practical

Answer 48

To observe and count the number of stomata on a leafs surface

Question 49

What are the equipment’s needed for this experiment (stomata imprint) 6

Answer 49

.leaves .clear nail varnish .sharp tweezers .microscope slide .pipette . Microscope

Question 50

What is the first step in this experiment (stomata imprint)

Answer 50

Painting a small patch of nail varnish on the leafs top side

Question 51

Why must the nail varnish be fully dry before removing it

Answer 51

To ensure a complete and accurate imprint of the stomata

Question 52

Why should the observation be done over high power on the microscope (stomata imprint)

Answer 52

To clearly see and count individual stomata’s

Question 53

What’s the last step of the experiment (stomata imprint)

Answer 53

Repeat steps ….. but for the underside surface of the leaf

Question 54

Why is it necessary counting a mean of the number of stomata’s counted (stomata imprint)

Answer 54

Stomata distribution varies across a leaf, mean gives a more reliable result.

Question 55

Give 1 example each of sources and sinks

Answer 55

Sources: leaves Sinks: meristems

Question 56

Why are companion cells always found next to sieve tubes

Answer 56

Because when transporting substances the sieve tube is completely dependent on the companion cell which provides energy

Question 57

What are sugars converted to for storage

Answer 57

Starch

Question 58

What do plant cells use amino acids for

Answer 58

Building proteins