B1

Question 1

Eukaryotic cell

Answer 1

Complex and include all amimal and plant cells. Eukaryotes are organisms that are made up of eukaryotic cells.

Question 2

Prokaryotic cell

Answer 2

Smaller and simpler. A prokaryote is a prokaryotic cell.

Question 3

What sre the different parts of a cell called?

Answer 3

Subcellular structures

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 reactions

Question 6

Cell membrane

Answer 6

Holds the cell together and controls what goes in and out.

Question 7

Ribosomes

Answer 7

These are where proteins are made in the cell

Question 8

Rigid cell wall

Answer 8

Made of cellulose. It supports the cell and strengthens it

Question 9

Permanent vacuole

Answer 9

Contains cell sap, a weak solution of sugar and salts.

Question 10

Chloroplasts

Answer 10

These are where photosynthesis occurs, which makes food for the plant. Theyncontain a green substance called chlorophyll, which absorbs the light needed for photosynthesis.

Question 11

Do bacteria cells have chloroplast and mitochondria?

Answer 11

No

Question 12

What nucleus does bacteria have?

Answer 12

A single curcular strand of DNA that floats freely in the cytoplasm

Question 13

What is resolution?

Answer 13

The ability to distinguish between two points, so a higher resolution gives a sharper image.

Question 14

What is the formula for magnification?

Answer 14

Magnification = image size/real size

Question 15

How do you prepare a slide to view onion cells?

Answer 15

1) Add a drop of water to the middle of a clean slide.
2) Cut up an onion and separate it out into layers. Use tweezers to peel off
some epidermal tissue from the bottom of one of the layers.
3) Using the tweezers, place the epidermal tissue into the water on the slide.
4) Add a drop of iodine solution. lodine solution is a stain.
Stains are used to highlight objects in a cell by adding colour to them.
5) Place a cover slip (a square of thin, transparent plastic or glass) on top. To do this, stand the cover slip upright on the slide, next to the water droplet. Then carefully tilt and lower it so it covers the specimen.
Try not to get any air bubbles under there — they’ll obstruct your view of the specimen.

Question 16

How do you use a light microscope?

Answer 16

1) Clip the slide you’ve prepared onto the stage.
Select the lowest-powered objective lens (i.e. the one that produces the lowest magnification).
3) Use the coarse adjustment knob to move the stage up to just below the objective lens.
4) Look down the eyepiece. Use the coarse adjustment knob to move the stage downwards until the image is roughly in focus.
5) Adjust the focus with the fine adjustment knob, until you get a clear image of what’s on the slide.
6) If you need to see the slide with greater magnification, swap to a higher-powered objective lens and refocus.

Question 17

What is differentiation?

Answer 17

The process by which cell changes to become specialised for its job

Question 18

How are sperm cells specialised for reproduction?

Answer 18

The function of a sperm is basically to get the male DNA to the female DNA.
It has a long tail and a streamlined head to help it swim to the egg.
There are a lot of mitochondria in the cell to provide the energy needed.
It also carries enzymes in its head to digest through the egg cell membrane.