B1 Cell Structure

Question 1

How do you find magnification?

Answer 1

Magnification = Size of image / size of real object

(IAM triangle)

Question 2

How do you calculate the total magnification of a microsope?

Answer 2

Total Magnification = Eyepiece lens x Objective lens

Question 3

What is resolution?

Answer 3

The ability to distinguish between two separate points of an image

Question 4

Define ‘Magnification’

Answer 4

Magnification is how much bigger an image is compared to its actual size.

This can be calculated using the IAM triangle.

Question 5

What type of microscope is used to see organelles?

Answer 5

Electron Microscope

Question 6

How do you calculate percentage change in mass?

Answer 6

(Final mass - Initial mass) / (initial mass)

Question 7

What is a Prokaryotic Cell?

Answer 7

Smaller and simple cells with no nucleus

Question 8

What is a Eukaryotic Cell?

Answer 8

A complex cell containg a nucleus

Question 9

What is the function of the nucleus?

Answer 9

Contains genetic material (DNA) in the form of chromosomes, controls the cell

Question 10

What is the cytoplasm?

Answer 10

This is where chemical reactions occur

Question 11

What occurs in the mitochondria?

Answer 11

Where aerobic respiration takes place

Question 12

What happens in the chloroplasts?

Answer 12

This where photosynthesis occurs

Question 13

What happens in the ribosomes?

Answer 13

Where protien synthesis takes place

Question 14

What is the cell membrane?

Answer 14

Controls what enters and leaves the cell

Question 15

What is the cell wall?

Answer 15

A layer of cellulose used to strengthen and protect the cell

Question 16

What is the vacuole?

Answer 16

Contains the cell sap,water and minerals

Question 17

How do you get from 1000 micrometers to 1mm?

Answer 17

Divide by 1000

Question 18

What is the equation for aerobic respiration?

Answer 18

Glucose + Oxygen ——> Carbon Dioxide + Water Vapour + Energy (ATP)

Question 19

What type of DNA do prokaryoitc cells have?

Answer 19

1 single loop of DNA called plasmids

Question 20

Define diffusion.

Answer 20

The movement of particles from a high concentration to a low concentration

Question 21

Define osmosis

Answer 21

The movememt of water particles from a dilute solution to a concentrated solution through a partially permeable membrane

Question 22

What is a passive process?

Answer 22

An activity which dosen’t require ATP energy

Question 23

What is an active process?

Answer 23

An activity which ATP energy is required

Question 24

What is active transport?

Answer 24

The diffusion of substances

Question 25

What happens to an animal cell when it is placed in a more DILUTE solution?

Answer 25

The cell gains water by osmosis and may burst. This is called lysis.

Question 26

What happens to an animal cell when it is placed in a more CONCENTRATED solution?

Answer 26

The cell loses water by osmosis and shrivels. This is called crenation.

Question 27

What happens to a plant cell when it is placed in a more DILUTE solution?

Answer 27

The cell gains water by osmosis but does not burst. This cell is now turgid.

Question 28

Why does a plant cell not burst when it is placed in a more dilute solution?

Answer 28

The plant cell has a cell wall.

Question 29

What happens to an plant cell when it is placed in a more CONCENTRATED solution?

Answer 29

The cell loses water by osmosis. The cell membrane pulls away from the cell wall. This is is called plasmolysis.

Question 30

Give an example of a substance that moves by active ranspor

Answer 30

Mineral ions

Question 31

Adaptations of Sperm Cells

Answer 31

- Streamlined head and a long tail (to help swim) - Many mitochondira to aid movement - Contains a digestive enzyme to break the outer layer of the egg

Question 32

Adaptations of nerve cells

Answer 32

- Nerve endings contain many mitochondria - Long axons to enable impulses to be carried along long distances - Has many extenstions from the cell for branced connections

Question 33

Adaptations of muscle cells

Answer 33

- Lots of mitochondria - Store glycogen - Have special protiens which slide over each other (*causing muscles to contract*)

Question 34

Adaptations of root hair cells

Answer 34

- Large surface area to store more water - Large permanent vacuole (*affects the speed of osmosis from soil to cell*) - Lots of mitochondria (*energy needed for active ranspor*)

Question 35

Adaptations of xylem cells

Answer 35

- Hollow - Joined end to end to form a continuous tube - Lignin is deposited in spirals (*which helps the cell wall withstand high pressure*)

Question 36

Adaptations of phloem cells

Answer 36

- Have a companion cell with mitochondria to supply energy - Fewer organelles for food to move faster - Cell walls form structures called *sieve plates* allowing the movement of substances from cell to cell

Question 37

Pros and Cons of an electron microscope

Answer 37

**Pros** - higher magnification and resolution (*can see organelles*) **Cons** - expensive - can't see colour

Question 38

Pros and Cons of a light microscope

Answer 38

**Pros** - image is coloured - cheap - high voltage isn't required **cons** - limited magnification

Question 39

How do you convert mm into µm

Answer 39

X1000

Question 40

If you place a human hair on a microscope slide, and look at it under a microscope, is the hair itself considered the object or the image?

Answer 40

Object, The hair itself is the object because it's the real hair sitting on the slide.

Question 41

If you look at cheek cells under a microscope, are the shapes that you see when looking down the microscope the object or the image?

Answer 41

Image, The shapes you see are the image because they are a magnified version of the real object, created by the microscope

Question 42

How do you convert µm into mm?

Answer 42

Divide by 1000

Question 43

How do bacteria reproduce?

Answer 43

By binary fission,

Question 44

How do you making bacteria culture with aspetic techniques?

Answer 44

1) Lift the lid of the petri dish towards flame to sterilse 2) Spread a drop of culture on agar evenly 3) Put discs of antibiotic on culture if needed 4) Few bits of tape (*to allow aerobic respiration*) and incubate at 25°C 5) Later, measure size of area with no bacteria

Question 45

Why is osmosis passive?

Answer 45

Because it requires no energy