Required Practicals - Plant Responses

Question 1

What is the goal of the plant responses practical?

Answer 1

To investigate the effect of gravity or light on the growth of a plant (seedlings).

Question 2

What is the method for the plant responses practical?

Answer 2

-Take 2 separate plants of the same species.
-Place a bin bag over both and insert a hole at different sides.
-Make observations about where the plants are facing towards.
-Place a light source at the hole.
-Give both plants water.
-Leave the light source on for 24 hours with the bin bag still on top of the plant and afterwards record observations about the direction the plants have grown in.

Question 3

What is the independent variable for the plant responses practical?

Answer 3

Light intensity

Question 4

What is the dependent variable for the light intensity practical?

Answer 4

Height of the different seedlings

Question 5

What do we do first in the plant responses practical?

Answer 5

Place cotton wool in three petri dishes and soak them with equal volumes of water.

Question 6

What is the volume of water in the plant responses practical?

Answer 6

A control variable

Question 7

What is placed in each dish in the plant responses practical?

Answer 7

10 mustard seeds

Question 8

What do we do after placing mustard seeds in dishes?

Answer 8

Leave them in a warm place and allow them to germinate

Question 9

What do we do to the seeds every day in the plant responses practical?

Answer 9

Water them with the same volume of water.

Question 10

What is the number of seedlings in the plant responses practical?

Answer 10

A control variable

Question 11

How do we measure the height of each seedling in the plant responses practical?

Answer 11

Using a ruler

Question 12

How should the three dishes be placed in the plant responses practical?

Answer 12

In different conditions, one in full sunglight, one in partial light and one in darkness

Question 13

How often do we measure the height of each seedling in the plant responses practical?

Answer 13

Once a day for 5 days.

Question 14

Why are the results similar for full sunlight and partial sunlight in the plant responses practical?

Answer 14

Chlorophyll is very efficient at absorbing light energy so they don’t need full sunlight

Question 15

Why do plants grow towards the light source in the plant responses practical?

Answer 15

Due to phototropism

Question 16

Where does auxin concentrate in a plant?

Answer 16

On the side of the plant furthest from the light, causing this side to grow faster.

Question 17

What have seedlings in darkness grown rapidly in the plant responses practical?

Answer 17

Seedlings normally germinate underground and need to grow rapidly to reach light

Question 18

Why are seedlings yellow in the darkness in the plant responses practical?

Answer 18

They cannot carry out photosynthesis in the dark

Question 19

What does auxin do to cell growth in roots and shoots?

Answer 19

Inhibits growth in roots and increases growth in shoots.