Plants

Question 1

Function of epidermal tissues

Answer 1

It is a protective tissue that covers the entire surface of the plant. the epidermis protects the plant from the infection and water loss

Question 2

Function of palisade mesophyll

Answer 2

For photosynthesis. The cells in here are packed tightly together and contain chloroplasts to maximize energy production during photosynthesis

Question 3

Function of spongy mesophyll

Answer 3

Allows for the interchange of gases (Co2) that are need for photosynthesis

Question 4

Function of xylem

Answer 4

It transports water from the roots to the stems and leaves, but it also transports nutrients. Also provides mechanical support and storage

Question 5

Function of phloem

Answer 5

It moves food substances that the plant has produced by photosynthesis to where they are needed for processes.

Question 6

Function of meristem tissue

Answer 6

A meristem is a collection of undifferentiated cells that can divide and become other specialized types of cells in the plant. Meristem tissue is important because it allows for plants to grow and repair damaged tissue

Question 7

Structure of the root

Answer 7

In the root, the xylem forms a central column. It forms a solid support. The phloem is towards the centre, outside the xylem

Question 8

Function of the root

Answer 8

Roots absorb water and nutrients from the soil. They anchor the plant firmly. They help in storing food and nutrients. Roots transport water and minerals to the plant

Question 9

How are root hair cells adapted to their function

Answer 9

Root hair cells have a very large surface area due to them being very long and having hair like projections. This allows more active transport of mineral ions to take place so the plant is able to take in as many important mineral ions as possible

Question 10

Effects of factors on the rate of transpiration

Answer 10

Several factors can affect the rate of transpiration, including temperature, humidity, air movement, and light intensity. Warmer temperatures generally lead to higher transpiration rates, while higher humidity levels decrease the rate of water loss.

Question 11

How does a potometer work

Answer 11

As water is
transpired
from the leaves, the shoot absorbs water from the potometer.

The distance the air bubble moves in a certain period of time can be used to calculate the rate of water uptake.

The apparatus is set up under water to prevent the entry of any unwanted air bubbles.

Question 12

Effect of wind on on the rate of transpiration

Answer 12

The faster the wind speed, the higher the rate of transpiration. This is because the movement of air across the surface of leaves causes evaporation of water from the mesophyll cells, and this loss of water must be replaced by water moving up the xylem vessels from the roots.

Question 13

Effect of humidity on the rate of transpiration

Answer 13

The higher the humidity, the lower the rate of transpiration as there is a lower concentration gradient so less evaporation

Question 14

Effect of temperature on the rate of transpiration

Answer 14

The higher the temperature, the faster the rate of transpiration as the particles have more kinetic energy so faster moving particles escape more easily

Question 15

Effect of light on the rate of transpiration

Answer 15

The higher the light intensity, the faster the rate of transpiration as light opens up the stomata.

Question 16

Role of guard cells

Answer 16

Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata

Question 17

Role of stomata

Answer 17

Stomata regulate gas exchange between the plant and environment and control of water loss by changing the size of the stomatal pore

Question 18

What is translocation and how are sugars transported around the plant

Answer 18

Translocation is the movement of materials in plants from the leaves to other parts of the plant. Nutrients, mainly sugars, are created in the leaves during photosynthesis. These are then transported throughout the plant through phloem, which are a long series of connected cells.

Question 19

Role of phloem tissue in translocation

Answer 19

Phloem tissue transports organic substances in plants. These organic substances include sugars, such as sucrose, and some minerals.

Question 20

Explain physical plant defence adaptations

Answer 20

Cellulose wall form a physical barrier between the cells and the pathogens, protecting it from infection

Question 21

Explain chemical plant defence adaptations

Answer 21

Produce compounds that have anti-microbial properties that can defend the plant from disease causing agents.

Question 22

Explain mechanical plant defence adaptations

Answer 22

A impenetrable barrier of bark and waxy cuticle. Others include hard shells thorns and spines.

Question 23

What is tobacco mosaic virus

Answer 23

Infects tobacco through contact with other plants(either naturally or by the hands of the farmers). It infects the chloroplasts and turns it from green to a yellow/white mosaic pattern. This reduces the plants ability to photosynthesize and grow properly. There is no cure for this disease.

Question 24

What is rose black spot

Answer 24

Caused by a fungus that which infects roses and causes black/purple spots on the leaves. Reduces the plants ability to photosynthesize. Transmitted through the air of the water and also through contact of gardeners.

Question 25

Define a tropism

Answer 25

A tropism is a growth in a plant in response to a stimulus. The stimulus could be a change in the direction of light or a water source