Biology - From Big to Small

Question 1

Nucleus

Answer 1

Controls the activity of the cell (by making proteins)
Contains the chromosomes - strands of DNA which carry the genes (each gene codes for a protein)

Question 2

Cell membrane

Answer 2

Boundary between the cytoplasm and the cell’s surroundings. Controls what substances enter and leave the cell

Question 3

Cytoplasm

Answer 3

Jelly-like liquid where chemical reactions occur

Question 4

Mitochondria

Answer 4

Carries out some reactions of aerobic respiration, producing ATP (energy carrier molecule)

Question 5

Ribosomes

Answer 5

Synthesise (assemble) proteins from amino acids

Question 6

Chloroplasts

Answer 6

Absorb light energy and use it to carry out the chemical reactions of photosynthesis, making biological molecules for plant cells

Question 7

Cell wall

Answer 7

Made of cellulose (a carbohydrate) in plants. Helps to keep plant cells in a fixed shape (and so keeps the plant upright)

Question 8

Vacuole

Answer 8

Filled with a watery liquid called cell sap; stores dissolved sugars, mineral ions and other substances

Question 9

Which of the 5 kingdoms are multicellular?

Answer 9

Plants and animals

Question 10

Cells

Answer 10

This is the smallest functional unit of life that contains a number of organelles, structures that carry out specific processes the cells need to survive

Question 11

Tissues

Answer 11

These are groups of similar cells which work together to carry out the same function (job)

Question 12

Example of tissues

Answer 12

Human muscle tissue

Question 13

Organs

Answer 13

These are made of several different tissues working together to carry out a more complex function

Question 14

Example of organs

Answer 14

In humans, muscle is one of the tissues making up the heart organ

Question 15

Organ systems

Answer 15

These are made up of several difference organs working together to carry out a complex function essential to life

Question 16

Example of organ systems

Answer 16

Circulating blood around the body

Question 17

What is the level of organisation in the body?

Answer 17

Atoms, molecules, organelles, cells, tissues, organs, organ systems and the human (organism)

Question 18

What chemical is used to test for simple sugars like glucose?

Answer 18

Benedict’s Solution

Question 19

How is Benedict’s solution used to test for simple sugars?

Answer 19

Mix with the food sample in a test tube and heat for 5 minutes in a hot water bath.

Question 20

What colour changes occur with Benedict’s solution if sugars are present in the samples you are testing?

Answer 20

A range of colours depending on the concentration of sugars e.g. Blue (none), green/yellow (traces of reducing sugar), orange/red (moderate), brick red (large amount of reducing sugar)

Question 21

What chemical is used to test for starch?

Answer 21

Iodine solution

Question 22

How is iodine solution used to test for starch?

Answer 22

Add a few drops of it with a food sample in a test tube

Question 23

What colour changes occur with iodine solution if starch is present in the samples you are testing?

Answer 23

Light orange/brown if not present or black/blue if present

Question 24

What chemical is used to test for protein?

Answer 24

Biuret solution

Question 25

How is Biuret solution used to test for protein?

Answer 25

Add 2cm³ water and shake it to a food sample in a test tube, add an equal volume of dilute potassium hydroxide and shake again, then add two drops of 1% copper sulphate solution

Question 26

What colour changes occur with Biuret solution if
protein is present in the samples you are testing?

Answer 26

Blue if not present or pale/purple if present

Question 27

What chemical is used to test for fats?

Answer 27

Ethanol emulsion

Question 28

How is ethanol emulsion used to test for fats?

Answer 28

Add 2cm³ water to the food sample in a test tube, add a small volume of absolute ethanol and shake, add an equal volume of water

Question 29

What colour changes occur with ethanol emulsion if fats are present in the samples you are testing?

Answer 29

Colourless if not present or milky-white if it present