Biology - Topic 1 - Key Concepts in Biology

Question 1

Whatdoesamicroscopedo?

Answer 1

makessmallobjectsappearlarger/magnifiessmallobjects

Question 2

Whatpartofamicroscopedoyoulookthrough?

Answer 2

eyepiecelens

Question 3

Whichpartofamicroscopedoyouusetogetaclearimage?

Answer 3

thefocusingwheel

Question 4

Puttheseinorderofsize,biggestfirst:atom,animalcell,cellnucleus,muscletissue,proteinmolecule,watermolecule

Answer 4

muscletissue,animalcell,cellnucleus,proteinmolecule,watermolecule,atom

Question 5

Amicroscopehasa×5eyepiecelensanda×5objectivelens.Whatisthetotalmagnification?

Answer 5

×25;5×5=25

Question 6

Ahumanhairhasawidthof100µmbutappears20mmwideinaphoto.Whatmagnificationisthephoto?

Answer 6

×200;20mm=20000µm;20000÷100=200

Question 7

Howmanymillimetresarethereinametre?

Answer 7

1000

Question 8

Whatunitis1000timessmallerthanamillimetre?

Answer 8

micrometre,µm

Question 9

Whatistheunitsymbolforananometre?

Answer 9

nm

Question 10

Name one part you could find in a plant cell but not an animal cell.

Answer 10

cell wall, chloroplasts, permanent vacuole

Question 11

What process happens in a mitochondrion?

Answer 11

aerobic respiration

Question 12

What is one function of a plant cell’s permanent vacuole?

Answer 12

to help keep the cell rigid/to store substances

Question 13

In which part of a plant cell is cell sap stored?

Answer 13

vacuole

Question 14

In which part of a cell would you find chromosomes?

Answer 14

nucleus

Question 15

When you look down a microscope, what is the area that you see called?

Answer 15

field of view

Question 16

Why can an electron microscope detect smaller structures in cells than a light microscope?

Answer 16

it has better magnification and better resolution

Question 17

What is a picture taken with a microscope called?

Answer 17

micrograph

Question 18

Some microscope pictures have a small line drawn on them with information about how long the line is when unmagnified. What is this line called?

Answer 18

scale bar

Question 19

List three sub-cellular structures that are usually

found in animal cells.

Answer 19

cell membrane, nucleus, mitochondria, ribosomes

Question 20

Which cell structure controls what enters and leaves the cell?

Answer 20

cell membrane

Question 21

Which cell structure controls how the cell works?

Answer 21

nucleus

Question 22

Which plant cell structure contains chlorophyll?

Answer 22

chloroplast

Question 23

What is the function of the cell structure that contains chlorophyll?

Answer 23

to capture energy from light for photosynthesis/to produce glucose using photosynthesis

Question 24

Describe the function of the cell wall

Answer 24

supports and protects the cell

Question 25

What is the function of ribosomes?

Answer 25

manufacture of proteins

Question 26

What are gametes?

Answer 26

sex cells

Question 27

A bacterium is 20 µm long. How long is it in metres?

Answer 27

0.00002 m

Question 28

A bacterium is 5 µm wide. How wide is it in nanometres?

Answer 28

5000nm

Question 29

What do bacteria use to move themselves?

Answer 29

flagella

Question 30

Animal and plant cells are eukaryotic. What word describes bacterial cells?

Answer 30

prokaryotic

Question 31

Name one structure that an animal cell would have but a bacterial cell would not.

Answer 31

nucleus, mitochondria

Question 32

What is 1 × 10^6m written as an ordinary number?

Answer 32

1 000 000 m

Question 33

Name two substances that might be found in the cytoplasm of an egg cell to provide energy.

Answer 33

carbohydrate or starch, lipid or fat or oil

Question 34

In which system of the body is food broken down?

Answer 34

digestive system

Question 35

Why do we need to break food down?

Answer 35

because the molecules in food are too large to cross cell membranes

Question 36

In which organ of the body is digested food absorbed?

Answer 36

small intestine

Question 37

Which group of molecules help to digest food?

Answer 37

enzymes

Question 38

Name an example of an enzyme

Answer 38

amylase, protease, lipase

Question 39

What does a sperm cell use enzymes for?

Answer 39

to digest a path through the jelly coat of the egg cell

Question 40

Do plants contain enzymes?

Answer 40

yes – they control many reactions inside plant cells

Question 41

Name a part of a plant where you might find | enzymes.

Answer 41

anywhere a reaction takes place, e.g. in chloroplasts for photosynthesis, in mitochondria for respiration, where starch grains are made

Question 42

What nutrient is starch an example of?

Answer 42

carbohydrate

Question 43

Why are proteins and carbohydrates examples of polymers?

Answer 43

They are made up of many similar molecules/monomers.

Question 44

Which monomers make up starch?

Answer 44

glucose

Question 45

Which monomers make up a protein?

Answer 45

amino acids

Question 46

Are enzymes carbohydrates, proteins or lipids?

Answer 46

proteins

Question 47

Which group of substances are fats and oils examples of?

Answer 47

lipids

Question 48

Name one food that contains a lot of starch.

Answer 48

potato, pasta, bread, rice

Question 49

What effect does the enzyme amylase have on starch?

Answer 49

breaks it down to small sugars

Question 50

Food provides nutrients for growth. What else is it a source of, which we need for activity?

Answer 50

energy

Question 51

What are the subunits (small molecules) that make up carbohydrates?

Answer 51

simple sugars, e.g. glucose

Question 52

Which two kinds of subunits form lipids (fats and oils)?

Answer 52

fatty acids and glycerol

Question 53

Which subunits make up enzymes?

Answer 53

amino acids

Question 54

Amylase is a kind of enzyme. Where is it found?

Answer 54

mouth/salivary glands and small intestine/pancreas

Question 55

Why are enzymes called biological catalysts?

Answer 55

They are molecules found inside living organisms that speed up the rate of reactions.

Question 56

What is a substrate?

Answer 56

A molecule that is changed in a reaction

Question 57

What is the substrate for amylase?

Answer 57

starch

Question 58

Starch synthase is an enzyme that catalyses the synthesis of starch. Explain what this means.

Answer 58

The enzyme combines with subunits/small sugar molecules and helps them join together to form starch.

Question 59

Why do different enzymes have different 3D shapes?

Answer 59

The amino acids are arranged in a different order in different proteins.

Question 60

Which kind of large organic molecule does a protease digest?

Answer 60

proteins

Question 61

What is the name of the part of an enzyme into which the substrate fits?

Answer 61

active site

Question 62

Why do most enzymes only work with one | substrate?

Answer 62

Only substrates with the same shape as the active site can sit in the site and take part in the reaction.

Question 63

Enzymes are specific to their substrate. What does | this mean?

Answer 63

The enzyme will only work with particular substrates -those substrates that have the right shape.

Question 64

Which term describes an enzyme in which the active site has permanently changed shape?

Answer 64

denatured

Question 65

What effect does a large change of shape of an enzyme's active site have on how the enzyme works?

Answer 65

The enzyme no longer works.

Question 66

Give two examples of changes in the cell environment that could cause the active site to change shape.

Answer 66

pH, temperature

Question 67

Carbon dioxide is produced inside a cell and moves out of the cell by diffusion. What does this mean?

Answer 67

there is an overall movement of gas particles from | where there are more of them to where there are fewer

Question 68

Name two substances that plants take in from the soil through their roots

Answer 68

water and dissolved mineral salts

Question 69

There is a 5% sucrose solution and a 10% sucrose solution. Which solution has the higher concentration of sucrose?

Answer 69

10% solution

Question 70

Two beakers contain the same volume of solution. One is a 10% sodium chloride solution, the other is a 5% sodium chloride solution. Which beaker contains more water molecules?

Answer 70

5% solution

Question 71

Which solution is used to test for starch and what is the positive result?

Answer 71

Iodine solution turns from brown to blue/black

Question 72

Which solution is used to test for protein and what is the positive result?

Answer 72

Biurets solution turns from blue to purple

Question 73

What solution is used to test for reducing sugars and what is the positive result?

Answer 73

Benedicts solution, once heated, turns from blue to green/orange/red

Question 74

What solution is used to test for lipids and what is the positive result?

Answer 74

Ethanol turns from clear to cloudy.