Biology Paper One

Question 1

What is mitochondria?

Answer 1

Where aerobic respiration takes place on a cell

Question 2

What is that name of a process where cells changing to become specialised ?

Answer 2

Differentiation

Question 3

What is the name of the process of splitting and replication of prokaryotes?

Answer 3

Binary fission

Question 4

Name 5 ways to prevent contamination of culturing microorganisms.

Answer 4

• Use a sterilised petri dish
• Use a sterilised culture medium
• Sterilise inoculating loop over a flame
• Lightly tape on the lid of the petri dish
• Store plates upside down

Question 5

What is a risk of using stem cells in medical treatment?

Answer 5

The cells in the culture medium may become infected with a virus and transferred onto a patient

Question 6

What are advantages of embryonic stem cells? (Three)

Answer 6

• Cure diseases (eg diabetes or paralysis)
• Therapeutic cloning won’t reject them as they’re the same genes
• Embryos used are usually unwanted from IVF clinics and would have been destroyed

Question 7

What are the disadvantages of embryonic stem cells? (Four)

Answer 7

• Potential human life (embryos) being killed
• Banned in some countries
• Must follow strict guide lines
• There are other sources of stem cells, not just embryos

Question 8

What is therapeutic cloning?

Answer 8

Production of an embryonic with the same genes as the parents

Question 9

Define diffusion

Answer 9

Spreading out of particles from high concentrations to low concentration, involving a net movement

Question 10

What are sugar molecules used in cells?

Answer 10

Energy

Question 11

What is the function of a root hair cell?

Answer 11

Taking up substances from the soil

Question 12

What is the structure of a root hair cell?

Answer 12

Elongated ‘hairs’ that stick out into soil

Question 13

What is the usefulness of root hair cells?

Answer 13

Increase surface area

Question 14

What four features make effective gas exchange in animals?

Answer 14

• Good blood flow
• Large surface area
• Thin membrane (short diffusion pathway)
• Being ventilated

Question 15

Why are there air spaces in leaves?

Answer 15

Increase the surface area for gas exchange and flow, (CO2 in, O2 and H2O(g) out)

Question 16

What are the three main parts of a gill on a fish and what are they useful for?

Answer 16

• LAMELLAE - increase surface area
• GILL FILAMENTS - increase surface area
• LOTS OF CAPILLARIES - good blood flow
|——>all for gas exchange (O2 in H2O)

Question 17

What is a biological valve?

Answer 17

A valve take from another human or mammel

Question 18

What is a mechanical value?

Answer 18

An artificial valve

Question 19

What drug is taken to control HIV?

Answer 19

Antiretroviral drugs

Question 20

Describe the appearance of leaves with rose black spot (three)

Answer 20

• Purple or black spots
• Yellow leaves
• Leaves drop off

Question 21

How is Rose black spot spread?

Answer 21

In air (wind) or water

Question 22

How does the skin defend itself against pathogens?

Answer 22

• Secretes antimicrobial substances

* Acts as a barrier

Question 23

Do painkillers kill the pathogen?

Answer 23

No as they don’t kill the pathogens

Question 24

What happens is a double blind trail?

Answer 24

• Patients randomly split into two groups
• One group given placebo and one given real drug
• Neither the patients or doctors know who’s been given which one until results have been gathered
• This prevents the placebo effect

Question 25

What are monoclonal antibodies?

Answer 25

Produced from lots of clones of a single white blood cell, so they're identical and will only target one specific protein antibody

Question 26

Name an insect that damages plants

Answer 26

Aphids

Question 27

Formula for photosynthesis:

Answer 27

Carbon dioxide + water -> glucose + oxygen

Question 28

Formula for aerobic respiration:

Answer 28

Glucose + oxygen -> carbon dioxide + water

Question 29

Formula for anaerobic respiration:

Answer 29

Glucose -> lactic acid (+some energy)

Question 30

Formula for anaerobic respiration in yeast and plants:

Answer 30

Glucose -> ethanol + carbon dioxide

Question 31

Five uses of glucose in plants:

Answer 31

* For respiration * Making cellulose * Making amino acids * Stored as fats or pips * Stored as starch

Question 32

Why does lack of chlorophyll mean reduced rate of photosynthesis?

Answer 32

Not enough light can be absorbed

Question 33

The improvements and explanations of how to improve conditions for photosynthesis in green houses:

Answer 33

IMPROVEMENT: adding a heater EXPLANATION: increasing temperature increases rate of photosynthesis IMPROVEMENT: supplying artificial light EXPLANATION: increasing light increases rate of photosynthesis IMPROVEMENT: adding a paraffin heater EXPLANATION: increases CO2 concentration to increase rate of photosynthesis

Question 34

What's an exothermic reaction and give a biological example:

Answer 34

A reaction where energy is transferred TO environment (eg respiration)

Question 35

What's an endothermic reaction and give a biological example:

Answer 35

A reaction where energy is transferred TO environment (eg photosynthesis)

Question 36

Three uses of the energy transferred in respiration:

Answer 36

* To build up larger molecules from smaller ones * Allow muscles to contract (move) * Maintain body temperature (in birds and mammals)

Question 37

Physical effect on muscles after vigorous exercise:

Answer 37

* Becoming fatigued | * Stop contracting properly