B1 (Cells And Organisms)

Question 1

Eukaryotes

Answer 1

• made up of eukaryotic cells

- complex include animal and plant cells

Question 2

Prokayotes

Answer 2

• made of prokaryotic cells

- single celled organism

Question 3

Nucleus

Answer 3

• animal and plant cell

- DNA stored

Question 4

Cytoplasm

Answer 4

• animal and plant cell

- chemical reactions and enzymes

Question 5

Cell membrane

Answer 5

• animal and plant cell

- supports cell and controls what goes in and out

Question 6

Mitochondria

Answer 6

• animal and plant cell

- aerobic respiration to release energy

Question 7

Ribosomes

Answer 7

• animal and plant cell

- proteins made

Question 8

Cell Wall

Answer 8

• just plant cells

- contains cellulose, strengthens

Question 9

Permanent Vacuole

Answer 9

• just plant cells

- contains sap

Question 10

Chroloplasts

Answer 10

• just plant cells

- contains chlorophyll for photosynthesis and energy

Question 11

5 differences between Bacteria and Animals/plant cells

Answer 11

• smaller
• no mitochondria
• no chloroplasts
• don’t have true nucleus, DNA floating
• can contain extra DNA

Question 12

Light Microscopes

Answer 12

• uses light and lenses

- can magnify to see cells and nuclei

Question 13

Electron microscopes

Answer 13

• higher resolution then light
• uses electrons
• higher magnification
• sees smaller things (ribosomes) in more detail

Question 14

Magnification=

Answer 14

Image size / real size

Question 15

0.0025 in standard form

Answer 15

2.5 x 10(^-3)

Question 16

Relationship between micrometers and millimetres

Answer 16

1000 micrometers = 1 millimetre

Question 17

Sperm Cells

Answer 17

• specialised for reproduction
• long tail and streamline
• lots of mitochondria for energy and enzymes

Question 18

Nerve Cells

Answer 18

• specialised for Rapid Signalling
• long cells to transfer electrical impulses
• branches

Question 19

Muscle Cells

Answer 19

• specialised for contractions
• long cells
• lots of mitochondria for respiration for energy

Question 20

Root Hair cells

Answer 20

• specialised for absorbing Water and Mineral ions

- hair stick out into soil giving large SA to absorbs

Question 21

Phloem and Xylem Cells

Answer 21

• specialised for transporting substances (food and water

- Xylem hollow centres and Phloem few sub-cellular structures for flow

Question 22

Diffusion (3)

Answer 22

• spreading out of particles
• area of high to low concentration (against a gradient)
• requires energy

Question 23

Where and why does diffusion occur?

Answer 23

• in solutions and gases that have small molecules, through cell membrane
• particles free to move

Question 24

3 ways to increase rate of diffusion

Answer 24

• higher concentration gradient
• higher temperature, particles more energy
• increase surface area, more pass through at once

Question 25

Osmosis (3)

Answer 25

- Movement of water molecules - from high water concentration to low water concentration (against a concentration gradient) - across a partially permeable membrane

Question 26

What is Net Movement in Osmosis?

Answer 26

- steady flow of water molecules into concentrated solution (not water)

Question 27

3 stages of effects of sugar solution required practicle

Answer 27

1) cut potato and get different solution concentration (independent), with one pure water 2) measure mass (dependant), then leave for 24 hours (control) 3) take out and dry measure mass

Question 28

3 potential errors of sugar solution required practicle

Answer 28

- not fully dried effects mass - water evaporated from beakers - concentration change

Question 29

Active Transport (3)

Answer 29

- movement of mineral ion - from low concentration to high concentration (against a concentration gradient) - requires energy

Question 30

Active Transport in root hair cells

Answer 30

- allows to absorb minerals from dilute solution | - needs respiration to work

Question 31

Active Transport to stop us starving

Answer 31

Allows nutrients (gut) into blood due to the concentration gradient

Question 32

Exchanging surfaces in single-celled organisms

Answer 32

- dissolved substances directly through cell membrane | - large SA:VOL ratio so enough exchanged for volume

Question 33

4 adaptions of exchanging surfaces

Answer 33

- thin membrane, shorter diffusion - large SA, lot's of diffusion - Animals lot's of blood vessels to increase rate - Ventilated gas exchange to keep flow

Question 34

4 examples of exchanging substances

Answer 34

- gas exchange for respiration - villi for digestion - structure of leaves for flow of 02 and CO2 - gills in fish for O2 from water and CO2 leave