B4 Plant Organisation & Transport 📚🛵

Question 1

What is the tissue that covers the whole plant?

Answer 1

Epidermal Tissue

Question 2

Where does most of the photosynthesis happen in the plant?

Answer 2

Palisade Mesophyll Tissue

Question 3

What part of the leaf contains big air spaces?

Answer 3

Spongy Mesophyll tissue

Question 4

What things does the Spongy mesophyll tissue contain?

Answer 4

Is in the leaf and contains big air spaces for gasses to diffuse in and out of the cell

Question 5

What transports water and mineral ions in plants?

Answer 5

Xylem and Phloem

Question 6

Through what does the Xylem and Phloem transport things like food?

Answer 6

Through roots, stems and leaves

Question 7

Where is the meristem tissue found?

Answer 7

In the shoots and roots of the plant

Question 8

What is the meristem tissue?

Answer 8

Found at the roots and shoots of the plant, this has the ability to differentiate into many other plant cell types allowing the plant to grow

Question 9

What is the order of tissues / organs in the leaf top to bottom?

Answer 9

Epidermal tissue, Palisade mesophyll, Spongy mesophyll, Epidermal tissue (covered by tiny whole called stomata and guard cells)

Question 10

What is the Epidermal tissue covered by to prevent water loss?

Answer 10

Waxy cuticle to prevent water lose through evaporation

Question 11

How is the upper epidermis adapted to allow maximum light pass?

Answer 11

It is transparent allowing the sun light to reach the palisade mesophyll tissue below

Question 12

Where is the palisade mesophyll layer located in the leaf?

Answer 12

Near the top under the upper epidermis to receive maximum light

Question 13

What does the palisade layer contain allowing it to photosynthesis?

Answer 13

Chloroplasts

Question 14

What do the xylem and phloem tissues do.

Answer 14

The Xylem and Phloem cells produce a network of vascular bundles where minerals and water are delivered through the entire leaf. They also take away the glucose produced by photosynthesis. They also help support the plant’s structure

Question 15

What is the lower epidermis covered with?

Answer 15

Little holes called stomata

Question 16

What do the stomata do?

Answer 16

The stomata located in the lower epidermis (bottom of the leaf) allow CO2 to diffuse directly into leaf, and also let O2 out. The opening and closing of the stomata are controlled by guard cells.

Question 17

What does the air spaces in the spongy mesophyll do?

Answer 17

Increases the rate of diffusion of gasses

Question 18

What do Phloem cells transport?

Answer 18

Transport food substances that are mainly dissolved sugars made in the plant for immediate use like in growing regions or for storage.

Question 19

What is cell sap?

Answer 19

Cell sap is a liquid that’s made up of the substances being transported and water.

Question 20

What direction does the transportation of food take place in the Phloem?

Answer 20

In Both directions

Question 21

What is the process of transporting food through the phloem called?

Answer 21

Translocation

Question 22

What is the structure of phloem tubes?

Answer 22

They are made up of elongated living cells with small pored in the end walls to allow cell sap to flow through

Question 23

In what direction do the xylem tubes transport water ?

Answer 23

Up ^

Question 24

What is the structure of xylem tubes?

Answer 24

Made up of dead cells joined end to end with no end walls between them and a holder down the middle. The xylem tubes are strengthen by a material called lignin.

Question 25

What is the job of xylem tubes?

Answer 25

They carry water and mineral ions from the roots to the stems and leaves

Question 26

What is the movement of water from the roots through the xylem and out of the leaves called?

Answer 26

The transpiration stream

Question 27

What is transpiration?

Answer 27

Is the loss of water from the plant

Question 28

Where and how does transpiration happen?

Answer 28

Most of the transpiration is at the leaves and is caused by evaporation and diffusion

Question 29

What does the evaporation cause in the transpiration process?

Answer 29

The evaporation causes a shortage meaning more eater is drawn up through the xylem vessels to replace it. Meaning more water is drawn up from the roots and so there is a constant stream of water through the plant.

Question 30

What causes the water to diffuse out of the plant and into the air around it?

Answer 30

Due to there being more water inside the plant than outside in the air, the water escapes from the leaves through the stomata by diffusion.

Question 31

What are the 4 main things affecting the rate of transpiration?

Answer 31

Light intensity, Temperature, Air flow and Humidity

Question 32

How does light intensity affect the rate of transpiration?

Answer 32

The brighter the light, the greater the transpiration rate. Stomata begin to close when it gets dark, as no CO2 is taken because photosynthesis can't happen in the dark. When the stomata are closed very little water can escape.

Question 33

How does temperature affect the rate of transpiration?

Answer 33

The warmer = the faster the rate of transpiration - When it is warm, the water particles have MORE ENERGY to evaporate and diffuse out of the stomata.

Question 34

How does Air Flow affect the rate of transpiration?

Answer 34

The better the air flow (stronger winds) the greater the transpiration rate - This is because when there is poor air flow, the water vapour is just surrounding the leaf without moving. Meaning there is a high concentration of water particles outside the leaf as well as in - so diffusion is quite slow. - Good air flow means the water is being swept away maintaining a low concentration of water outside the leaf - meaning diffusion happens quickly from an area of high concentration to and area of low concentration

Question 35

How does Humidity affect transpiration rate?

Answer 35

The drier it is around the leaf, the quicker transpiration happens. - Dry = low water amount outside of leaf, high to low concentration meaning diffusion is faster - Wet = high water amount outside of leaf, meaning high concentration to high concentration meaning diffusion is slow

Question 36

How can you estimate the rate of transpiration?

Answer 36

You can do this by measuring the uptake of water by a plant assuming the water uptake is directly related to water loss by leave's transpiration.

Question 37

How do you set up a Potometer?

Answer 37

1) Set up the potometer, then record the starting position of the air bubble. 2) Start a stopwatch and record the distance moved by the bubble per unit time e.g hour 3) Making sure to keep the conditions constant throughout the experiment e.g temperature and air humidity

Question 38

What is a MASS potometer?

Answer 38

The mass potometer measures loss of mass through transpiration.

Question 39

What is the MOVING BUBBLE potometer?

Answer 39

The moving bubble potometer measures the water uptake by a plant, by measuring how far an air bubble has moved in a certain time like 1 hour.

Question 40

What are Guard Cells adapted to do?

Answer 40

Guard cells are adapted for has exchange and controlling water loss within a leaf.

Question 41

When do guard cells allow the stomata to OPEN?

Answer 41

When the plant has lots of water the guard cells fill with it and go plump and turgid. This makes the stomata open so that gases can be exchanged for photosynthesis.

Question 42

When does the guard cells make the stomata CLOSE?

Answer 42

When the plant is short of water, the guard cells lose water and become flaccid making the stomata close to reduce the amount of water vapour escaping.

Question 43

How does the opening and closing work in a stomata with guard cells?

Answer 43

Thin out wall and thickened inner walls make the opening and closing work.

Question 44

When is another example of when guard cells close the stomata not relating to too little/much water?

Answer 44

They also close at night, because they are sensitive to light this is to save water without loosing out on photosynthesis.