Chapter 1

Question 1

Three rules of cell theory

Answer 1

1. All living organisms are composed of cells
   2.Cells are the smallest unit of life
2. Cells come from pre-existing cells (there is no spontaneous generation)
   two more:
3. Cells contain a blueprint for their growth, development and behaviour
4. Cells are the site for all chemical reactions of life

Question 2

What are the types of atypical cells?

Answer 2

• striated muscle cells
• Acetabularia (Giant algae)
• Aseptate fungal hyphae

Question 3

1000 nm=

Answer 3

1 micrometer (mm)

Question 4

1000 mm=

Answer 4

1 milimetre (mm)

Question 5

Magnification formula

Answer 5

Magnification= size of drawing (observed)/ actual size

Question 6

Examples of unicellular organisms

Answer 6

bacteria, archaea, protozoa, unicellular algae and unicellular fungi

Question 7

Functions of life

Answer 7

MRHGREN

Metabolism, reproduction, homeostasis, growth, response, excretion, nutrition

Question 8

is a virus a living cell?

Answer 8

• it doesn’t carry out all the functions of life
• Does not metabolise or reproduce (uses hosts cell to do that)
• not classified as living

Question 9

two examples of unicellular living organisms

Answer 9

1. Paramecium (protozoa)

2. Chlamydomonas (unicellular green algae)

Question 10

Differences between Chlamydomonas and Paramecium

Answer 10

• C uses flagella for movement, P uses cilia
• P consumes food, C makes using photosynthesis
• C uses entire plasma membrane for excretion, P expels using anal pore

Question 11

Osmoregulation

Answer 11

A constant internal environment is maintained by collecting excess water in the contractile vacuoles and then expelling it through the plasma membrane.

Question 12

What is the cytoplasm?

Answer 12

The site of all chemical reactions of the cell (i.e. Metabolism)

Question 13

Centrosome

Answer 13

An organelle that lies close to the nucleus in animal cells

Question 14

Differences between plant and animal cells

Answer 14

Plant:

1. Cellulose cell walls
2. Fluid filled permanent vacuole
3. no centrosome
4. contains chloroplasts

Question 15

optimum surface area: volume ratio?

Answer 15

• As the size of the cell increases, volume exceeds SA. Thus, the SA can not provide for the increasing volume
• The smaller the cell is, the easier the exchange between the cytoplasm and the environment

Question 16

Genes definition

Answer 16

1. A length of DNA that codes for a protein

2. A region of a chromosome that determines the development of a specific characteristic of an organism

Question 17

Stem cell

Answer 17

A cell that has the capacity for cell division while remaining undifferentiated (self renewal) and the ability to differentiate into mature cell types (potency).

Question 18

Differences between embryonic and adult stem cells

Answer 18

1. Found in embryo / found in organs

2. Can develop into many types of cells/ limited range for development (blood stem cells–> blood)

Question 19

Uses of stem cells in medical therapies

Answer 19

1. Stargardt’s disease (regenerates damaged light sensitive cells of the retina)
2. Parkinsons disease (death of neurons in the part of the brain that controls subconscious muscle activities)
3. Type 1 diabetes (damage of beta cells producing insulin)
4. Cardiac muscle damage (death of muscle fibres)