Chapter 2: Organisms in the environment

Question 1

What is the word equation for photosynthesis?

Answer 1

Carbon Dioxide + Water —–> Glucose + Oxygen

Question 2

What substance does photosynthesis take place in?

Answer 2

Chlorophyll

Question 3

Where is chlorophyll found?

Answer 3

In Chloroplasts.

Question 4

If not all of the glucose created in photosynthesis is used immediately, what is the glucose stored as?

Answer 4

Insoluble Starch

Question 5

What does Iodine solution Test for?

Answer 5

Starch

Question 6

How do you test for starch?

Answer 6

Using Iodine Solution (Yellow = no starch, Blue = starch)

Question 7

How is a leaf adapted to its task of photosynthesis? (4 main reasons)

Answer 7

1. They have a large surface area
2. They contain Chloroplasts w/ chlorophyll to absorb light energy
3. They have stomata and air spaces to allow Carbon Dioxide to reach cells inside the leaf
4. They have veins which bring water to the cells

Question 8

What is the top layer of cells on a leaf called?

Answer 8

The upper epidermis

Question 9

What is the function of the upper epidermis?

Answer 9

To excrete a ‘waxy cuticle’ which protects the leaf from water or other unwanted particles entering it.

Question 10

What is the second layer of a leaf called? What is it’s function?

Answer 10

The palisade layer, its where most photosynthesis takes place.

Question 11

How is the ‘palisade layer’ adapted to do it’s job?

Answer 11

1. Lots of chloroplasts to absorb light energy
2. Close to the surface to maximize light reaching it
3. Compact arrangement to maximize area that can photosynthesise

Question 12

What is the third layer of cells in a leaf called? What is it’s function?

Answer 12

The spongy layer. It allows carbon dioxide to diffuse into the cells to aid photosynthesis.

Question 13

What is the last layer of a leaf called?

Answer 13

The lower epidermis

Question 14

Name the limiting factors of Photosynthesis.

Answer 14

Light Levels, Temperature and Carbon dioxide concentration.

Question 15

From 0 to a higher value, levels of light and carbon dioxide will cause the rate of photosynthesis to increase. However, past a certain point the increase will level out. Why?

Answer 15

The rate of Light/Carbon dioxide uptake is greater than the rate at which the plant can use it up.

Question 16

From 0 to a higher value, increasing Temperature will cause the rate of photosynthesis to increase. However, past a certain point the rate will suddenly fall. Why?

Answer 16

The enzymes that control photosynthesis are denatured.

Question 17

How do plants make amino acids?

Answer 17

By combining mineral ions (e.g. nitrate ions) with glucose

Question 18

How is glucose used in a plant?

Answer 18

It is combined with oxygen to produce energy which goes into chemical reactions inside cells.

Question 19

Why do we prefer to grow crops/fruit in greenhouses?

Answer 19

1. The environment can be controlled much more accurately

2. Less risk of attack from pests

Question 20

Systems that strive to take complete control over the limiting factors of plants/photosynthesis are grouped as…

Answer 20

Hydroponics

Question 21

What are the limiting factors for organisms?

Answer 21

1. Temperature
2. Nutrient Levels
3. Amount of light
4. Availability of water
5. Availability of Oxygen or Carbon dioxide

Question 22

What tool could you use to measure the distribution of plant life or small animal life?

Answer 22

A Quadrat

Question 23

What must you never ever Ever EVER do with a Quadrat?

Answer 23

Throw it! D:

Question 24

How do you choose the sample sites when using a quadrat?

Answer 24

You must choose them randomly.
A good way to do this is by dividing the area up into a grid and using a random number generator to generate co-ordinates.

Question 25

When you had finished using a quadrat to sample an area, what would you do to your results?

Answer 25

Find the mean number of organisms per sample.

Question 26

What is sampling along a transect?

Answer 26

Following a set path between two points (usually a line) and measuring the amount of an organism at regular intervals using a quadrat.

Question 27

When you sample along a transect, what are you measuring?

Answer 27

The change in the distribution of an organism along a path. This can be linked to other factors that also change along the path, such as light and ph levels or temperature.

Question 28

What is a reproducible method?

Answer 28

A reproducible method is one which can can be repeated by others and found to produce similar results each time.

Question 29

What is valid data?

Answer 29

Data that answers the question that the investigation poses.