B16, B17, B1

Question 1

Chloroplast function:

Answer 1

Photosynthesis

Question 2

Cell wall function:

Answer 2

Made of cellulose, gives the cell strength and support.

Question 3

Vacuole function:

Answer 3

Contains cell sap (which keeps cell rigid) and controls cell water levels.

Question 4

Cytoplasm function:

Answer 4

Jelly like substance where most chemical reactions take place

Question 5

Nucleus function:

Answer 5

Contains DNA and controls the activities of the cell.

Question 6

Cell membrane function:

Answer 6

Bodyguard of the cell.
Controls the movement of substances in & out of the cell.

Question 7

Ribosome function:

Answer 7

Protein synthesis.

Question 8

Mitochondria function:

Answer 8

Releases energy from aerobic respiration.

Question 9

Magnification:

Answer 9

How large an image will appear in comparison to it’s actual size.

Question 10

Resolution:

Answer 10

The clarity of objects that are very close together.

Question 11

Magnification equation:

Answer 11

Image = Actual x Magnification

Question 12

Eyepiece lens:

Answer 12

Lens closest to the eye.

Question 13

Objective lens:

Answer 13

There are 3 lenses of different strengths which can be used to magnify the image more clearly.

Question 14

Stage:

Answer 14

Where the slide is put. The clip holds the slide in place.

Question 15

Diaphragm:

Answer 15

Controls the amount of light that goes on the slide.

Question 16

Light:

Answer 16

Projects light onto the slide. Usually a mirror or electric bulb.

Question 17

Base:

Answer 17

This is very heavy to keep the microscope from falling over.

Question 18

Arm:

Answer 18

Holds the eyepiece lens above the stage.

Question 19

Fine focus knob:

Answer 19

Used to focus the image so it is very sharp and clear.

Question 20

Coarse focus knob:

Answer 20

Used to focus the image so it is very sharp and clear.

Question 21

Prokaryotes:

Answer 21

Bacterial cells. Have a cell wall, cell membrane, genetic material, cytoplasm, plasmids and flagella.

Question 22

Eukaryotes:

Answer 22

Cells with a nucleus (animal and plant cells).

Question 23

Specialised cell examples:

Answer 23

• Sperm cell (carries genetic information to egg cell, tail allows it to swim).
• Red blood cell (transports oxygen required for aerobic respiration, no nucleus = more room for haemoglobin. Lots of haemoglobin = can carry more oxygen).
• Palisade cell (Photosynthesis; lots of chloroplasts = maximise absorption of light)

Question 24

Stem cell:

Answer 24

An undifferentiated cell which can become any type of cell.

Embryonic stem cell, Adult stem cell, Plant stem cell

Question 25

Embryonic stem cell:

Answer 25

- In the embryo. - Can differentiate into any type of body cell. - Use: Can treat any type of disease.

Question 26

Adult stem cell:

Answer 26

- In bonemarrow. - Can only differentiate in some cell types. - Use: Bone marrow transplant.

Question 27

Stem cell ethics:

Answer 27

Embryo For: - Treatment for disease that previously had no cure. - Many embryos naturally lost at this stage (abortion or discarded from IVF) Embryo Against: - Concerns that could cause cancer due to rapid growth. - Moral, ethical and religious views against. Adult for: - Come from volunteers - Less likely to become cancerous. Adult against: - Pre-specialised, EG blood stem cells make only blood cells.

Question 28

Cell cycle stage 1:

Answer 28

- Cell grows in size - Increase in number of organelles - DNA duplicates

Question 29

Cell cycle stage 2 (mitosis):

Answer 29

- Chromosomes line up in the middle. - 1 copy of each chromosome is pulled to the side. - Nucleus divides.

Question 30

Cell cycle stage 3:

Answer 30

- Cytoplasm & cell membrane divide. - To form 2 genetically identical daughter cells.

Question 31

Food chain order:

Answer 31

Producers - make own food with photosynthesis. Primary consumers Secondary consumers Tertiary consumers

Question 32

Predators, prey & apex predators:

Answer 32

Predators = eat live prey. Prey = gets eaten by predators. Apex predators = do not get eaten by anything else.

Question 33

Predator/prey relationship:

Answer 33

- Less predators than prey. - Prey increases, predators increase. - More food available so predators can reproduce more. - Prey decreases, predators decrease. - Less prey = less food = starvation.

Question 34

Decay cycle:

Answer 34

- Decomposers return nutrients to soil. - eg fungi, bacteria, insects/worms - dead animals/plants and faeces decompose. - key nutrients are recycled into the soil by decomposers. - eg carbon and nitrogen.

Question 35

Carbon cycle:

Answer 35

- Carbon in atmosphere absorbed by plants for photosynthesis. - Plants consumed by animals - carbon bioaccumulated into their bodies. - Animals and plants eventually die, and decomposing releases carbon back into atmosphere.

Question 36

Water cycle:

Answer 36

Transpiration: Water taken in roots of plants is sent back into the atmosphere as water vapour. Evaporation: Water evaporates from bodies of water, due to light energy from the sun. Condensation: After evaporation and transpiration, the water vapour cools, forming liquid clouds. Transport: When liquid clouds are formed, they can be pushed far distances by wind. Precipitation: Rain, snow, sleet and hail fall from the clouds into the bodies of water and the land. Surface runoff: Sometimes, when there is a large amount of precipitation, water runs along the earth to enter bodies of water. Infiltration: Some water that falls is absorbed into the ground. It can then be stored in aquifers. These are underground, permeable rocks.

Question 37

Biodiversity:

Answer 37

All species living in a certain ecosystem.

Question 38

Human population explosion:

Answer 38

- less people dying - healthier lifestyle - no natural predators - population increasing rapidly

Question 39

land pollution:

Answer 39

landfill litter plastic (non biodegradable)

Question 40

air pollution:

Answer 40

from fossil fuels CO2 released in air contributes to greenhouse effect -> global warming

Question 41

community:

Answer 41

all the organisms that live in a habitat

Question 42

ecosystem:

Answer 42

the interaction of a community with non living parts of their environment.

Question 43

global warming

Answer 43

ice caps melt -> rising sea levels -> loss of houses environmental issues -> animals have to adapt

Question 44

sulfid dioxide acid rain:

Answer 44

- sulfur dioxide dissolves in rainwater to make sulfuric acid. - harms and kills plants - damages statues and buildings

Question 45

method to count number of daisies on a field:

Answer 45

use a quadrat and count number of daisies. repeat process at least 10 times. find the mean and multiply by total area of field.

Question 46

what is a quadrat?

Answer 46

a 1m x 1m piece of equipment set down to count a number of organisms.

Question 47

random sampling:

Answer 47

unbiased randomly placed quadrats to get a representative sample of the number of organisms in an area.

Question 48

transect sampling:

Answer 48

tape measure/line used to mark a sample area. quadrat used at regular intervals to count number of organisms.