Topic 1 - The Building Blocks of Cells

Question 1

How do light microscopes work?

Answer 1

• Light passes through a specimen

- Then through magnifying lenses

Question 2

What are microscope used for?

Answer 2

To learn about the STRUCTURE and the FUNCTION of cells.

Question 3

Define a clone

Answer 3

Individuals that are genetically identical

Question 4

Explain what needs to be done to clone a plant. (2) what is this an example of?

Answer 4

1) Take a bit of leaf, stem or root from the plant that is being cloned
2) The plant cells will divide and produce new cells

• asexual reproduction

Question 5

Name 1 advantages and 2 disadvantages of cloning animals

Answer 5

A: 1) useful to make a genetically identical copy of an organism with desirable characteristics

D: 1) very few embryos develop successfully
2) grow much quicker so die younger than normal

Question 6

Describe how to clone a mammal () what is this process called?

Answer 6

1) the nucleus of a body cell of the animal being cloned is taken
2) it is tranferred into an enucleated egg cell

Question 7

What does the cell membrane do? (2)

Answer 7

• Seperates the contents of a cell from its surroundings

- Controls movement of substances

Question 8

What substances do cell membranes control the movement of? (3)

Answer 8

• oxygen
• glucose
• carbon dioxide

Question 9

Which part of a cell do many of the chemical reactions occur? And what does this also contain?

Answer 9

• Cytoplasm

- organelles

Question 10

Define organelles.

Answer 10

Tiny structures that carry out specific jobs

Question 11

What is the nucleus of a cell?

Answer 11

• An organelle that contains DNA.
• It is the genetic material of the cell
• Controls all the activities in the cell

Question 12

Give 3 examples of an organelle.

Answer 12

• nucleus
• mitochondria
• chloroplasts

Question 13

What part of the cell is an organelle where respiration occurs? Describ them.

Answer 13

Mitochondria - very tiny, oxygen and glucose react to release energy for the cell

Question 14

What are the 3 extra features that a plant cell has?

Answer 14

• Cell wall
• Vacuole
• Chloroplasts

Question 15

What does the cell wall do and whats it made of?

Answer 15

• Made of tough cellulose

- Supports the cell and keeps its shape

Question 16

What is the space in the cytoplasm that is filled with cell sap called? What is its function?

Answer 16

Large vacuole - supports plant by keeping the cells rigid

Question 17

What do chloroplasts contain? Describe this substance

Answer 17

Chlorophyll - a GREEN substance that ABSORBS light energy for PHOTOSYNTHESIS

Question 18

Name the 4 components of a animal cell and the 7 of a plant cell.

Answer 18

Animal - cell membrane, nucleus, cytoplasm, mitochondria

Plant - nucleus, cell wall, cytoplasm, cell membrane, chloroplasts, vacuole, mitochondria

Question 19

What do better microscopes allow us to do?

Answer 19

• observe very small structures inside cells

Question 20

When was the electron microscope invented? How does it work?

Answer 20

1930s - uses a beam of electrons to magnify specimens

Question 21

How much can an electron microscope magnify a sunstance by?

Answer 21

2,000,000 times

Question 22

What have electron microscopes helped us to discover? How come?

Answer 22

More about the detailed structures of a cell - they produce very clear images

Question 23

What two types of DNA do bacteria cells have?

Answer 23

Chromosomal

Plasmid

Question 24

Whats the difference between chromosomal and plasmid DNA?

Answer 24

C.DNA - a giant loop containing most of the genetic material

P.DNA - small loops which carry extra info