BIOLOGY BASICS

Question 1

What is DIFFUSION?

Answer 1

DIFFUSION is the net movement of particles from an area of high concentration to an area of low concentration, down a concentration gradient

Question 2

What is OSMOSIS?

Answer 2

The net movement of water molecules from an area of high water potential to low water potential across a semi-permeable membrane

Question 3

What is ACTIVE TRANSPORT?

Answer 3

The active movement of substances across a semi-permeable membrane, against a concentration gradient, using energy from respiration

Question 4

Factors that affect the rate of diffusion:

Answer 4

1) SA:V ratio- a larger surface area in proportion to the volume means there is a larger area over which diffusion is taking place, and therefore the rate is increased
2) diffusion distance- the rate is increased if the distance over which diffusion has to take place is shorter
3) concentration gradient- diffusion happens more quickly when there is a steeper concentration gradient
4) temperature- high temperatures provide the particles with more kinetic energy, so they move around faster and collide more frequently, increasing the rate of diffusion

Question 5

DEFINE: AEROBIC RESPIRATION

Answer 5

The breaking down of glucose in the presence of oxygen to release energy in the form of ATP, and produce waste products of carbon dioxide and water

Question 6

DEFINE: ANAEROBIC RESPIRATION

Answer 6

Respiration in the absence of oxygen that produces lactic acid and releases little amounts of energy in the form of ATP

Question 7

What do plants use glucose for?

Answer 7

R- RESPIRATION
A- amino acids
L-lipids (energy store seeds)
S-starch (long term energy store)
S-sucrose
C-cellulose for cell walls

Question 8

ANAEROBIC RESPIRATION EQUAITON: PLANTS + FUNGI

Answer 8

Glucose —-> ethanol + carbon dioxide

Question 9

LEVELS OF ORGANISATION

Answer 9

Organelles —> cells—->tissues—->organs—->system

Question 10

HYDROGEN-CARBONATE indicator

Answer 10

High carbon dioxide=yellow
Medium=orange
Low = purple

Question 11

Arguments for and against using embryonic stem cells

Answer 11

FOR:
-can cure a wide range of diseases
-prevents the body from rejecting any medical treatments
-proven to be effective (bone marrow transplants)
-possibility to save hundreds of lives outweighs the embryo rights
-many unused embryos from fertility clinics are disposed anyways

AGAINST:
-unethical argument (should an embryo be treated as a human or as a commodity?)
-cloned embryos ownership problems
-embryonic stem cells can accumulate mutations and cause cancer
-embryonic stem cells can catch viruses in labs and be transmitted to people