Cell Structure and Microscopes

Question 1

How do you calculate the total magnification of a microscope?

Answer 1

Eyepiece lens magnification x objective lens magnification

Question 2

How do you calculate the magnification of an image?

Answer 2

Size of image ÷ real size of object

Question 3

How many micrometres are in a millimetre?

Answer 3

1,000 (one thousand)

Question 4

How many nanometres are in a millimetre?

Answer 4

1,000,000 (one million)

Question 5

What is 120 000 000 in standard form?

Answer 5

1.2 × 10^8

Question 6

What is 0.000007 in standard form?

Answer 6

7 × 10^-6

Question 7

How can you improve the resolution of a microscope (make it clearer)?

Answer 7

Turn the fine focus knob

Question 8

How can you improve the magnification of an image when using a microscope (make it bigger)?

Answer 8

Turn to a higher power objective lens

Question 9

Who first observed cork cells using a compound microscope?

Answer 9

Robert Hooke

Question 10

What is a limitation of the light microscope?

Answer 10

Fairly low resolution - cannot distinguish 2 points closer than 200 nm.

Question 11

Which cell structure is only visible when using an electron microscope (and not with a light microscope)?

Answer 11

Ribosomes

Question 12

What is the function (job) of the cytoplasm?

Answer 12

A jelly-like material where most chemical reactions happen

Question 13

What is the function (job) of the nucleus?

Answer 13

Contains genetic material (e.g. DNA), and controls the cell’s activities

Question 14

What is the function (job) of the cell membrane?

Answer 14

Controls the movement of substances into and out of the cell

Question 15

What is the function (job) of the mitochondria?

Answer 15

The site of aerobic respiration, which releases energy to the cell

Question 16

What is the function (job) of the ribosomes?

Answer 16

The site of protein synthesis (where proteins are made)

Question 17

Which three organelles (structures) are found in a plant cell, but not in an animal cell?

Answer 17

Chloroplasts, vacuole, cell wall

Question 18

What is the function (job) of the chloroplasts?

Answer 18

The site of photosynthesis, a chemical reaction where plants make their own food

Question 19

What is the function (job) of the cell wall?

Answer 19

Strengthens the cell and supports the plant

Question 20

What is the name of the green pigment in the chloroplasts that absorbs sunlight for photosynthesis?

Answer 20

Chlorophyll

Question 21

What is the cell wall made from?

Answer 21

Cellulose fibres

Question 22

What is the vacuole filled with?

Answer 22

Cell sap

Question 23

What is the function (job) of the vacuole?

Answer 23

Helps to keep the plant cell turgid

Question 24

How many orders of magnitude bigger is a 700 μm cell than a 7 μm cell?

Answer 24

2 orders of magnitude (10^2)

Question 25

What are three examples of eukaryotic cells?

Answer 25

Animals, plants and fungi

Question 26

What is an example of a prokaryotic cell?

Answer 26

Bacteria

Question 27

What are three structures NOT found in a bacterial (prokaryotic) cell?

Answer 27

- Nucleus - Mitochondria - Chloroplasts

Question 28

How is DNA stored in a bacterial cell?

Answer 28

- Free in the cytoplasm | - Additional DNA is stored in rings called plasmids

Question 29

How do bacterial cells divide?

Answer 29

By binary fission

Question 30

Name three adaptations a sperm cell has to help it perform its function.

Answer 30

- The acrosome (head) contains enzymes so the sperm can penetrate the egg - The middle piece contains many mitochondria to release the energy needed for the sperm to swim - The tail enables the sperm to swim - The sperm has a streamlined shape

Question 31

Name three adaptations a nerve cell has to help it perform its function (job).

Answer 31

- Nerve cells are extended to help them run to and from different parts of the body - Nerve cells have extensions and branches to help them communicate with other nerve cells - The nerve cell is covered with a fatty sheath, which insulates the cell and speeds up the electrical impulse

Question 32

What is one way that muscle cells are adapted for their function (job)?

Answer 32

Muscle cells contain many mitochondria to release the energy needed for muscle contraction

Question 33

What are two adaptations of a root hair cell to allow it to carry out its function (job)?

Answer 33

- Large surface area for absorbing more water | - Thin cell walls - not to restrict movement of water

Question 34

How are xylem cells adapted for their function (job)?

Answer 34

- No top and bottom walls between xylem cells, so water can flow freely - Thickened woody walls to support the plant

Question 35

What is the function of the xylem vessel in plants?

Answer 35

To carry water

Question 36

What is the function of the phloem vessel in plants?

Answer 36

To carry dissolved sugars and amino acids