B1

Question 1

Cells

Answer 1

Cab be either prokaryotic or eukaryotic

Question 2

Eukariotic cells

Answer 2

Include all animal and plant cells. Contains nucleus

Question 3

Prokaryotic cells

Answer 3

Smaller amd simpler compared to eukaryotic eg. Bacteria no nucleus

Question 4

Nucleus

Answer 4

Contains genetic material that controls the activities of the cell

Question 5

Cytoplasm

Answer 5

Gel-like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reaction

Question 6

Cell membrane

Answer 6

Holds the cell together and controls what goes in and out

Question 7

Ribosomes

Answer 7

Site of protein synthesis (where proteins are made)

Question 8

Animal cells

Answer 8

Nucleus, cytoplasm, cell membrane, mitochondria and ribosomes

Question 9

Plant cells

Answer 9

Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, cell wall, permanent vacuole, chloroplasts

Question 10

Rigid cell wall

Answer 10

Made of cellulose. It supports the cell and strengthens it

Question 11

Permanent vacuole

Answer 11

Contains cell sap

Question 12

Chlorplasts

Answer 12

Where photosynthesis occurs, which makes food for plants. Contain chlorophyll which absorbs light needed for photosynthesis

Question 13

Light microscopes

Answer 13

Use light and lenses to form an image of the specimen

Question 14

Electron microscopes

Answer 14

Uses electrons instead of light to from an image. Higher magnification than light microscopes

Question 15

Magnification formula

Answer 15

Magnification=image size/real size

Question 16

Units

Answer 16

1km=1000m,1m=100cm,1cm=10mm,1mm=1000micrometres,1micrometre=1000nanometres

Question 17

Preparing slide microscope

Answer 17

Clean slide, cut onion and seperate layer using tweezers, place the tissues into water on slide, add drop of iodine to stain, place cover on slip carefully lowering so no air bubbles

Question 18

Using microscope

Answer 18

Clip in slode, select lowest magnification lense, use coarse adjustment knob, look down eyepiece adjusting knob until rough image, adjust focus eith focus adjustment knob until get clear image of slide, if need swap to higher magnification lense

Question 19

Cell differentiation

Answer 19

When a cell changes to become specialised for certain jon

Question 20

Sperm cells- reproduction

Answer 20

To get male DNA to female DNA. Long tail and streamlined head to swin to egg and has lots of mitochondria for energy

Question 21

Nerve cells-rapid signalling

Answer 21

Carry electrical signals from one part of body to another. Long and have branched connections at their ends to connect to other nevre cells and form a network throughout the body

Question 22

Muscle cells for contraction

Answer 22

Function to contract quickly

Question 23

Root hair cells for absorbing water and minerals

Answer 23

Cells on surface of plant roots which grow out into hairs that stick out into the soil giving plant larger surface area for absorbing water and mineral ions from soil

Question 24

Phloem and xylem cells-transporting substances

Answer 24

Form phloem and xylem tubes

Question 25

Phloem tubes

Answer 25

Transport food

Question 26

Xylem tube

Answer 26

Transports water and mineral ions

Question 27

Diffusion

Answer 27

Spreading out of particles form an area of higher concentration to area of low concentration

Question 28

Conecntration gradient

Answer 28

Difference in concentration

Question 29

What speeds updiffusion rate

Answer 29

Bigger concentration gradient, higher temperature as particles will have more energy, larger surface area of the membrane

Question 30

Osmosis

Answer 30

The movements of water molecules across a parially permeable membrane from a region of higher water concentration to a region of lower water concentration

Question 31

concentrated

Answer 31

Low concentration of water

Question 32

Dillute

Answer 32

High concentration of water

Question 33

Active transport

Answer 33

Substances absorbed against concentration gradient from lower to higher concentration

Question 34

Active transport in plants

Answer 34

Allow the plant to absorb minerals from very dillute solution against concentration gradient so they can grow.

Question 35

What is need for active transport

Answer 35

Energy from respiration

Question 36

Active transport in humans

Answer 36

When there is lower concentration of nutrients in gut than blood diffusion wont be able to transport the nutrients to the blood

Question 37

Surface area to volume ratio

Answer 37

As an organism gets bigger the surface area to volume ratio decreases increasing the difficulty to exchange material quick enough

Question 38

Exchnage surfaces are adapted to maxmium effectiveness

Answer 38

Large surface area so lots of substance can diffuse at once, thin membrane so short distance to diffuse

Question 39

Exchange surfaces in animals

Answer 39

Lots of blood vessels to get stuff into and out of blood quickly, often ventilated air moves in and out

Question 40

Mitochondira

Answer 40

Mitochondria the site of aerobic respiration, so they release energy for the cell