2.6.7- Plant Tissues And Organs

Question 1

Define what an organ is.

Answer 1

A collection of tissues that work together to perform a function or related functions.

Question 2

Describe what the phloem is.

Answer 2

Tissue that carries the products of photosynthesis in solution within plants.

Question 3

Describe what the xylem us.

Answer 3

Tissue that carries water and mineral ions from the roots to all parts of the plant.

Question 4

Explain what re epidermal tissue is.

Answer 4

Consists of flattened cells that form a protective covering on the leaves, stems and roots of a plant. Apart from guard cells, they lack chloroplasts.

Question 5

Xylem and phloem are present in ________ _________.

Answer 5

Vascular bundles.

Question 6

What two things are present in vascular bundles?

Answer 6

Xylem and phloem.

Question 7

Some epidermal cells can be impregnated with…

Answer 7

A waxy substance that forms a cuticle.

Question 8

How can the waxy substance that’s impregnated into come epidermal tissue cells be important to the plants?

Answer 8

It can help plants in dry places as these cuticles will reduce water loss.

Question 9

Describe what the vascular tissue of plants is.

Answer 9

It is concerned with transport and consists of xylem and phloem- both of which are present in vascular bundles.

Question 10

What do xylem vessels do?

Answer 10

Carry water and minerals from the roots to all parts of the plant.

Question 11

Explain the function of phloem sieve tubes in plants.

Answer 11

Transfer the products of photosynthesis (mainly sucrose) in solution from the leaves to parts of the plant that don’t photosynthesise- eg; roots, flowers and growing shoots.

Question 12

Meristematic tissue contains _______ cells.

Answer 12

Stem.

Question 13

Where is meristematic tissue found?

Answer 13

At the tips of the roots and shoots and at the cambium it vascular bundles.

Question 14

What does the rest of the plant tissue derive from?

Answer 14

Meristematic tissue?

Question 15

By what process does the rest of the tissue within a plant derive from the meristematic tissue in plants?

Answer 15

Differentiation.

Question 16

List five characteristics of meristems.

Answer 16

• thin walls with little cellulose
• no chloroplasts
• no vacuole
• can divide by mitosis
• can differentiate into any cell (pluripotent).

Question 17

Vascular tissue derives from meristematic tissue by _______ and ________.

Answer 17

Mitosis and differentiation

Question 18

Explain how cambium cells can differentiate into xylem vessels.

Answer 18

Lignin is deposited in their cell walls to reinforce and waterproof them (also killing the cells) and the ends of the cell breaks down so that xylem forms continuous columns with wide lumens in order to carry water and dissolved minerals.

Question 19

Explain how cambium cells can differently into phloem sieve tubes or companion cells.

Answer 19

Sieve tubes lose most of their organelles and sieve plates develop between them.
Companion cells retain their organelles and continue metabolic functions to provide ATP got active loading of sugars into the sieve tubes.

Question 20

what are the four plant organs?

Answer 20

Leaf
Root
Flower
Stem

Question 21

What is the main function of the leaf?

Answer 21

Photosynthesis.

Question 22

What are the three main functions of the root?

Answer 22

Anchorage in soil, absorption of mineral ions and water and storage (eg. Carbohydrates stored by carrot and parsnips).

Question 23

What are the five main functions of the stem?

Answer 23

Support, holds the leaves up to expose them to more sunlight, transport water and minerals, transport the products of photosynthesis, storage f the products of photosynthesis (eg. Potato tubers store starch).

Question 24

What is the function of the flower?

Answer 24

Sexual reproduction.

Question 25

What is a meristem?

Answer 25

An area of unspecialised cells within a plant that can divide and differentiate into other cell types.