Tissues in flowering plants

Question 1

What does dermal tissue form?

Answer 1

It forms the covering on a plant

Question 2

Name an example of dermal tissue

Answer 2

epidermis

Question 3

What is the main function of dermal tissue?

Answer 3

To protect the plant

Question 4

Dermal tissue may have secondary functions, depending on its location.
Give two examples.

Answer 4

1. Root hairs are extensions of the epidermis near the tip of the root and are designed to absorb water and minerals.
2. The epidermis of leaves and most stems are coated with a way cuticle to prevent water loss from the plant.

Question 5

Where is ground tissue found?

Answer 5

It occupies the area between the dermal and vascular tissues in a plant

Question 6

List 3 functions of ground tissue.

Answer 6

It carries out a range of functions such as:

1. photosynthesis
2. Storage of food and wastes
3. gives strength and support to a plant

Question 7

What does vascular tissue consist of?

Answer 7

Xylem and phloem

Question 8

What is the main function of vascular tissue?

Answer 8

To transport materials throughout the plant

Question 9

Name the types of cells that xylem is made up of

Answer 9

Xylem is made up of two types of cells: vessels and tracheids

Question 10

What happens to the living contents of tracheids and vessels before they reach maturity?

Answer 10

They die

Question 11

When do the living contents of tracheids and vessels die?

Answer 11

before they reach maturity

Question 12

Why is xylem a dead cell?

Answer 12

As the living contents of tracheids and vessels die before they reach maturity

Question 13

Describe the appearance of xylem tracheids (4)

Answer 13

1. They are long, sloping or tapering cells
2. whose insides are hollow at maturity.
3. They overlap and
4. allow water to pass from tracheid to tracheid through thin parts of the wall called pits.

Question 14

How do xylem tracheids pass water to each other?

Answer 14

They overlap and allow water to pass from tracheid to tracheid through thin parts of the wall called pits.

Question 15

Where are xylem tracheids found?

Answer 15

They are the only type of xylem found in coniferous trees such as pine trees.

Question 16

Define lignin

Answer 16

Lignin is a strengthening material found in some plant cell walls

Question 17

Describe the structure of xylem vessels

Answer 17

They are tubular structures formed when a number of cells join end-to-end.

Question 18

How do xylem vessels differ from tracheids?

Answer 18

They are wider than tracheids and their end walls break down to form a continuous tube.

Question 19

What do xylem vessels have in their walls? What is their purpose?

Answer 19

They have pits in their walls to allow water to pass from one vessel to another.

Question 20

How are vessels better than tracheids?

Answer 20

They are more efficient at transporting water than tracheids

Question 21

Where are xylem vessels commonly found?

Answer 21

They are very common in flowering plants

Question 22

What are cells that contain lignin said to be?

Answer 22

Lignified

Question 23

What do tracheids and vessels have in common in terms of their structure?

Answer 23

They both have thick, lignified cell walls that gives them strength

Question 24

What definite pattern is most common for lignin?

Answer 24

spiral

Question 25

Give the functions of xylem (2)

Answer 25

1. It transports water and mineral salts from the roots to the leaves.
2. It also gives mechanical support to the plant (due to lignin)

Question 26

Where is xylem found in plants?

Answer 26

It is found in roots, stems, leaves and flowers. It is often found in vascular bundles.

Question 27

What is phloem composed of?

Answer 27

Sieve tubes and companion cells

Question 28

How is phloem a living cell?

Answer 28

As companion cells are alive, phloem is a living cell

Question 29

describe the structure of sieve tubes

Answer 29

They are long, tubular structures.

Question 30

When do sieve tubes form?

Answer 30

when individual cells, called sieve-tube elements, join end-to-end.

Question 31

Why do the end walls develop pores?

Answer 31

The end walls develop pores, which allow the passage of materials from one element to another.

Question 32

Why are end walls called sieve plates?

Answer 32

The end walls are called sieve plates because they resemble plates with numerous pores in them.

Question 33

The end walls develop pores, which allow the passage of materials from one element to another.
What happens to these elements?

Answer 33

The cytoplasm of each element remains, although the nucleus degenerates.

Question 34

What are the cell walls of sieve tubes made of?

Answer 34

cellulose but lignin is not present

Question 35

What does each sieve tube element have accompanying it?

Answer 35

Each sieve tube element has an accompanying companion cell on its outside.

Question 36

What do companion cells contain?

Answer 36

These have a nucleus and dense cytoplasm

Question 37

Where is phloem located?

Answer 37

Found in the roots, stems, leaves and flowers

Question 38

Summarise all 4 differences between xylem and phloem

Answer 38

Xylem:

1. Carries water and minerals
2. Is dead
3. Has lignin
4. has no companion cells

Phloem:

1. Carries food
2. Is living
3. Has no lignin
4. Has companion cells

Question 39

What must be labelled on a diagram for vessels? (5)

Answer 39

cell wall, lignin, pit, remains of old end wall, hollow lumen

Question 40

What must be labelled on a diagram for tracheids? (4)

Answer 40

Lignin, cell wall, pit and hollow lumen

Question 41

What must be labelled on a diagram for LS of phloem? (6)

Answer 41

Companion cell, sieve tube element, hollow lumen, cell wall, sieve plate, sieve tube

Question 42

What must be labelled on a diagram for the TS (transverse section) of phloem? (3)

Answer 42

Companion cell, sieve tube (element) and sieve plate