From Big to Small

Question 1

Nucleus function

Answer 1

1. Controls the activity of the cell
2. Contains chromosones - strand of DNA which carry the genes

Question 2

Cell membrane function

Answer 2

1. Acts as a boundary between cytoplasm and cell surroundings
2. Controls which substances enter and exit the cell

Question 3

Cytoplasm function

Answer 3

1. Jelly-like liquid where chemical reactions occur

Question 4

Mitochondria function

Answer 4

1. Carries out respiration producing ATP

Question 5

Ribosomes function

Answer 5

1. Synthesise proteins from amino acids

Question 6

Chloroplasts function

Answer 6

1. Absorb light energy and use it to carry out photosynthesis

Question 7

Cell wall funtion

Answer 7

1. Made of cellulose
2. Helps to keep plant cells in fixed shape

Question 8

Vacoule function

Answer 8

1. Filled with cell sap
2. Stores dissolved sugar and mineral ions

Question 9

State the levels of organisation

Answer 9

Organelles —> Cells —> Tissues —> Organs —> Organ system —> Organism

Question 10

Cell definition

Answer 10

Cells contain a number of organelles, structures that carry out different processes in order for the cell to survive

Question 11

Tissue definition

Answer 11

Tissues are a group of similar cells which work together to carry out the same function.

Question 12

Organ definition

Answer 12

Organs are made up of several different types of tissues working together to carry out a more complex function.

Question 13

Organ system definition

Answer 13

Organ systems are made up of several different organs working together to carry out an essential function to life.

Question 14

Elements making up carbohydrates

Answer 14

carbon, hydrogen and oxygen

Question 15

Smallest units of carbohydrates

Answer 15

glucose and fructose

Question 16

What is starch used for?

Answer 16

To store glucose in plants

Question 17

What is glycogen used for?

Answer 17

To store glucose in animals and fungi

Question 18

What are lipids made up of?

Answer 18

Carbon, hydrogen and oxygen

Question 19

Smallest units of lipids

Answer 19

Fatty acids and glycerol

Question 20

Functions of lipids

Answer 20

1. Energy storage
2. Part of cell membranes
3. Thermal insulation
4. Electrical insulation
5. Buoyancy

Question 21

What are proteins made up of?

Answer 21

Made of carbon, hydrogen, oxygen and nitrogen

Question 22

Smallest units of proteins

Answer 22

Amino acids

Question 23

Functions of proteins

Answer 23

1. Structural molecules such as collagen
2. Controlling chemical reactions - enzymes
3. Messenger molecules - hormones
4. Combating disease - antibodies
5. Transport - e.g haemoglobin and cells membrane proteins

Question 24

Step by step experiment for sugars

Answer 24

1. Add Benedict’s solution to a sample of food in a test tube
2. Place in water bath at 80°C for 5 minutes
3. If the test is positive the solution will turn brick red, negative will be blue

Question 25

Step by step experiment for starch

Answer 25

1. Add a few drops of orange iodine solution to the sample on a spotting tile 2. A blue-black colour indicates the presence of starch

Question 26

Step by step experiment for protein

Answer 26

1. Add water to a food sample and shake 2. Add an equal volume of dilute potassium hydroxide and shake 3. Add two drops of 1% copper sulfate solution 4. If protein is present then solution will turn lilac

Question 27

Step by step experiment for lipids

Answer 27

1. The food sample is placed in a test tube 2. Add a small volume of absolute ethanol and shake to dissolve any lipid in the alcohol 3. Add an equal volume of water 4. A cloudy white colour indicates the presence of lipids.

Question 28

Definition of enzymes

Answer 28

Enzymes are biological catalysts | A catalyst is a chemical which increases the rate of a reaction

Question 29

Explain the lock and key theory

Answer 29

1. The substrate and enzyme collide 2. The substrate binds to the active site of the enzyme 3. Enzyme substrate complex is formed 4. Enzyme and product complex are formed 5. Enzyme and products leave the active site

Question 30

What happens to the rate of an enzyme controlled reaction when temperature increases

Answer 30

As temperature increase enzyme and substrates have more kinetic enery they move move more meaning more collision. After the optimum temperature of 37.1°C the active site denatures meaning enzyme and substrate are no longer complementary.

Question 31

Propeties of plants

Answer 31

1. All multicellular - made of many cells 2. Make their own complex biological molecules by photosynthesis 3. Cells have chloroplasts for photosynthesis and cellulose for a cell wall 4. Store carbohydrates as starch or sucrose

Question 32

Propeties of animals

Answer 32

1. All multicellular - made of many cells 2. Eat of living things to obtain nutrients 3. Cells do not have chloroplasts or a cell wall 4. Store carbohydrates as glycogen 5. Have a nervous system

Question 33

Propeties of fungi

Answer 33

1. Many multicellular 2. Some have reproductive structure such as a mushroom or toadstool 3. Feed by saprotrophic nutrion 4. Cells have no chloroplasts, chitin cell wall and many nuclei per cell 5. Store carbohydrates as glycogen 6. Their body is organised into a mycelium from thread like structures called hyphae.

Question 34

Propeties of bacteria

Answer 34

1. Do not have a proper nucleus

Question 35

Example of plants

Answer 35

1) flowering plants - maize 2) herbaceous legume - peas or beans

Question 36

Examples of animals

Answer 36

1) mammals -humans 2) insects - housefly or mosquito).

Question 37

What is saprotrophic nutrition?

Answer 37

extracellular secretion of digestive enzymes onto food material and absorption of the organic products

Question 38

Examples of fungi

Answer 38

1) multi-cellular - Mucor, 2) single-celled - yeast

Question 39

Common features of protoctists?

Answer 39

1) microscopic single-celled organisms. 2) some have features like an animal cell, 3) others, have chloroplasts and are more like plants.

Question 40

Examples of protoctists

Answer 40

1) Amoeba - lives in pond water, has features like an animal cell 2) Chlorella - has chloroplasts and is more like plants. 3) Plasmodium - A pathogenic example, responsible for causing malaria.

Question 41

What is a pathogen?

Answer 41

A microorganism which causes infectious diseases. They do this by releasing toxins or damaging cells.

Question 42

What kingdoms can be pathogens?

Answer 42

1) Bacteria 2) Fungi 3) Protoctista and all viruses

Question 43

Properties of a virus?

Answer 43

1) Non-living organisms. 2) Parasitic 3) Can reproduce only inside living cells 4) Wide variety of shapes and sizes 5) No cellular structure 6) Have a protein coat and contain either DNA or RNA.

Question 44

What is the tobacco mosaic virus?

Answer 44

Causes discolouring of the leaves of tobacco plants by preventing the formation of chloroplasts

Question 45

Examples of viruses

Answer 45

1) The influenza virus that causes ‘flu’ 2) The HIV virus that causes AIDS.

Question 46

Similarities of plant an animal cells

Answer 46

They both have: - Mitochondria - Cytoplasm - Nucleus - Cell membrane - Ribosomes

Question 47

Differences of plant an animal cells

Answer 47

Plants have a permanent vacuole whilst animals do not. Plants have a cell wall whilst animals do not