Unit 1 - Key concepts

Question 1

What 2 types of cells are there

Answer 1

Prokaryotic and Eukaryotic

Question 2

What makes a cell Eukaryotic

Answer 2

If a cell has:
- A cell membrane
- A cytoplasm
- Nucleus containing DNA
Eukaryotic

Question 3

What makes a cell prokayotic

Answer 3

If a cell has:
- A cell wall
- A cell membrane
- A cytoplasm
- A plasmid of DNA

Question 4

What is a Nucleus

Answer 4

A nucleus is an organelle which contains DNA, which codes for a particular protein needed to build new cells

Question 5

What is the nucleic membrane

Answer 5

A membrane that contains the nucleus

Question 6

What is the cytoplasm

Answer 6

A liquid substance containing enzymes in which chemical reactions occur

Question 7

What is the cell membrane

Answer 7

A membrane which controls what enters and leaves the cell

Question 8

What is the mitochondria

Answer 8

Where aerobic respiration reactions occur

Question 9

What is the ribosomes

Answer 9

Where protein synthesis occurs

Question 10

What is the chloroplast

Answer 10

Where protein synthesis takes pace, providing food for the plant

Question 11

What is the vacuole

Answer 11

An organelle which contains cell sap, found within the cytoplasm.

Question 12

What is the cell wall

Answer 12

An organelle that is made from cellulose and provides strength to the cell

Question 13

What is the flagella

Answer 13

A long tail attached to bacteria allowing them to move

Question 14

What is a plasmid

Answer 14

A small ring of chromosomal DNA

Question 15

What process do cells go through to specialise

Answer 15

Differentiation

Question 16

What is a stem cell

Answer 16

A cell which can differentiate throughout its life

Question 17

What is a specialised cell

Answer 17

A cell which has been differentiated

Question 18

Give 3 examples of specialised cells in animals

Answer 18

1. Sperm cells
2. Egg cells
3. Ciliated epithelial cells

Question 19

How are sperm cells specialised to be suitable for its purpose

Answer 19

1. A streamlined head and long tails to aid swimming
2. Many mitochondria to supply a lot of energy
3. The acrosome which has digestive enzymes to break down the outer layer of the egg cell

Question 20

How are egg cells specialised to be suitable for its purpose

Answer 20

1. Surrounded by a special cell membrane which can only accept one sperm cell
2. A lot of mitochondria to provide an energy source for the developing embryo
3. Large size and cytoplasm to allow quick cell division

Question 21

How are Cilitated Epithelial Cells specialised to be suitable for its purpose

Answer 21

Long hair like processes called cilia waft bacteria trapped by sticky mucus down into stomach acid

Question 22

Give 3 examples of specialised cells in plants

Answer 22

1. Root hair cells
2. Phloem cells

Question 23

How are root hair cells specialised to be suitable for their functions

Answer 23

1. Specialised to absorb water through osmosis
2. Large surface area to increase water absorption

Question 24

How are Phloem cells specialised to be suitable for their functions

Answer 24

1. Sieve plates, which are formed in cell walls allowing substance movement between cells
2. Companion cells, which provide energy to phloem cells

Question 25

What do microscopes do

Answer 25

Enlarge images of structures like cells

Question 26

What 2 type of microscopes are there

Answer 26

Light and electron

Question 27

How do light microscopes work

Answer 27

2 lenses are illuminated from underneath

Question 28

What is the magnification of a light microscope

Answer 28

~2000x

Question 29

What is resolving power

Answer 29

The ability of an optical instrument or type of film to separate or distinguish small or closely adjacent images.

Question 30

What is the resolving power of a light microscope

Answer 30

200nm

Question 31

Lower ____ ∝ more ____

Answer 31

1. RP 2. Detail

Question 32

When was the electron microscope made

Answer 32

1931

Question 33

How do microscopes work

Answer 33

They use electrons to form an image, which have a much smaller wavelength than light

Question 34

What are the 2 types of electron microscopes

Answer 34

1. Scanning Electron Microscope (SEM) 2. Transmission Electron Microscope (TEM)

Question 35

Give 2 differences between SEM and TEM microscopes

Answer 35

1. SEM makes 3D images, and TEM makes 3D images 2. SEM's RP is 10nm, and TEM's RP is0.2nm

Question 36

Give 1 similarity between SEM and TEM microscopes

Answer 36

2,000,000x magnification

Question 37

How to calculate the magnification of a light microscope

Answer 37

M=M(EL)xM(OL) Where M=magnification EL=Eyepiece lens OL=Objective lens

Question 38

How to calculate the size of an objective

Answer 38

S(O)=S(I)/M Where S=Size O=Object I=Image M=magnification

Question 39

Name the 5 parts of a light microscope

Answer 39

1. Eyepiece 2. Barrel 3. Turret 4. Lens 5. Stage

Question 40

What is the function of the eyepiece

Answer 40

Used to view specimens

Question 41

What is the function of a barrel

Answer 41

To focus the image

Question 42

What is the function of the turret

Answer 42

To change the magnification of the used lens

Question 43

What is the function of the lens

Answer 43

Increase the magnification of the specimen

Question 44

What is the function of the stage

Answer 44

The flat surface on which we place the specimen

Question 45

How to use a light microscope

Answer 45

1. Place the slide on the stage and look through the eyepiece lens. 2. Turn the focus wheel to obtain a clear image. 3. Start with the lowest objective lens magnification. 4. Increase the magnification of the objective lens and refocus.

Question 46

How to prepare a slide

Answer 46

1. Take a thin layer of cells from your sample. 2. Add a small amount of chemical stain. 3. Apply the cells to your glass slide. 4. Carefully lower a coverslip onto your slide, avoiding air bubbles.