The Leaf

Question 1

What does plant organisation differ from animal organisation?

Answer 1

It doesn’t. Plants are organised in the same way other multicellular organisms are

Question 2

How exactly are plants organised?

Answer 2

Plant cells group together to form tissues. Plant tissues group together to form organs. Organs in a plant work together to form an organ system

Question 3

List examples of plant organs? What happens when organs like these bunch together

Answer 3

Leaf, stem and roots are all organs of the plant. Not specifically the ones listed above, but when plants organs come together, they group in order to carry out various functions that plants need to carry out in order to survive + grow

Question 4

What’s one example of a function plants need to survive and grow

Answer 4

The transport of substances in and around the plant

Question 5

What is the leaf and name some of the tissues that it contains

Answer 5

A leaf is an organ made up of several different plant tissue. Leaves contain spongy and palisade mesophyll as well as stomata, epidermis and xylem + phloem.

Question 6

There are five main plant tissues you need to know. List them.

Answer 6

Epidermal tissue, palisade mesophyll, spongy mesophyll, meristem tissue and xylem + phloem

Question 7

What are the four layers that make up the leaf?

Answer 7

The upper epidermis, the lower epidermis, the palisade layer and the spongy layer

Question 8

What is the role of epidermal tissue?

Answer 8

It covers the whole plant

Question 9

What is the function of the palisade mesophyll?

Answer 9

It’s the part of the leaf where photosynthesis happens. This tissue contains lots of chloroplasts which are helpful to carry out photosynthesis with.

Question 10

What is the function of the spongy mesophyll?

Answer 10

It contains air spaces so that gases and diffuse in and out of this layer (found in leaf)

Question 11

What are the xylem and phloem used for?

Answer 11

They transport things such as water, mineral ion, and food around the plant (via, shoots, roots and leaves

Question 12

What is a meristem?

Answer 12

It’s a type of cell that is undifferentiated. It’s like a plant stem cell. It can be found in the shoots and roots. It’s able to change differentiate. This means that they can grow into different type of cells, allowing the plant to develop and grow. These cells will never lose the ability to differentiate:

Question 13

Where is the waxy layer located? What’s it’s job?

Answer 13

It’s the very top layer of the leaf. It’s water proof, which also prevents water loss by evaporation. It’s an epidermal tissue

Question 14

Where are the palisade mesophyll located. What’s it’s job? What does it have to make it more efficient at its job?

Answer 14

It’s located underneath the waxy cuticle and it’s job is to help with photosynthesis. It has chlorophyll to help with that. It is also near the top of the leaf which means it can access light better there.

Question 15

Give one way in how the upper epidermis helps with photosynthesis

Answer 15

The upper epidermis is totally transparent, allowing light to pass through it, reaching a palisade layer where photosynthesis can happen

Question 16

What is the purpose of the spongy mesophyll. What does it have to help with said purpose?

Answer 16

It’s less densely packed compared to the palisade layer, and this layer is filled with air spaces. It’s job is to carry out diffusion of gas and air spaces make that easier. It also has a large SA to help with efficient gas exchange

Question 17

What do guard cells do?

Answer 17

They open and close stomata to help control water loss

Question 18

How will hot, dry days influence guard cells?

Answer 18

Evaporation rate will increase so amount of water lost is increased. Plants need to adapt to the conditions

Question 19

What are the purpose of the stomata?

Answer 19

They allow gases to move in and out of the leaf through them (they are holes)

Question 20

What are all the jobs of xylem and phloem?

Answer 20

Form a network of vascular bundle (vascular is responsible for transport) to move water and nutrients around the entire leaf. They also take the glucose made from photosynthesis to the rest of the leaf. They also help with structure of the leaf

Question 21

Some of the tissues of the leaf have adapted for gas exchange. Elaborate

Answer 21

Lower epidermis: full of holes (stomata) which lets CO2 in (directly). Opening and closing of the stomata rely on environmental conditions.
Air spaces in spongy mesophyll tissue helps increase rate of diffusion

Question 22

The leaf also has adapted to its conditions with 4 adaptions. Why have the leaves adapted?

Answer 22

They’ve adapted because it means that the plant can carry out as much photosynthesis as possible whenever there is light available.

Question 23

What are the four adaptions that leaves have taken? Elaborate.

Answer 23

They are broad (so they have a big surface area for light to fall on)
They contain chlorophyll (in the chloroplasts so they can absorb light energy)
They have air spaces (which allow CO2 in to get to the cell, also allows O2 to leave the leaf)
They have veins (have plenty of water to the cells of leaves)

Question 24

What have leaf tissue cells adapted to?

Answer 24

Maximise and make gas exchange efficient.