Biology yr 9 Spring Term

Question 1

hetrozygous

Answer 1

an organism where the alleles for a given trait are different

Question 2

Name the three methods of transport.

Answer 2

diffusion, osmosis, active transport

Question 3

active transport

Answer 3

the movement of a substance against a concentration gradient (from low to high) using energy from respiration.

Question 4

flaccid

Answer 4

when the plant is placed into a saturated solution and looses water

Question 5

hypotonic solution

Answer 5

a solution which is less concentrated than the inside of the cell

Question 6

adult animal stem cells

Answer 6

found only in specific areas of the body and can only develop into a limited number of cell types

found in adult animals

Question 7

concentration gradient

Answer 7

the difference in concentration of a substance between two areas

a region of high concentration leading to a region of low concentration

Question 8

problems with adult stem cells

Answer 8

• can only differentiate into smaller number of types of cells compared to embryonic stem cells
• donation can be painful

Question 9

Why do we need active transport?

Answer 9

• absorbing of mineral ions from soil
• movement of glucose from gut to kidney
• removal of salt from the body of marine animals
• absorption of ions from very dilute solutions

Question 10

Why do multicellular organisms have a small surface area to volume ratio?

Answer 10

their volume (internal space) increases faster than their surface area (outer boundary) as they grow larger

Question 11

homozygous

Answer 11

an organism where both alleles for a given trait are the same

Question 12

passive

Answer 12

does not require energy from respiration

Question 13

homologous

Answer 13

describes a matching pair of chromosomes

Question 14

How to gain marks on osmosis questions

Answer 14

1. State where is the solute concentration the highest
2. State that osmosis is the movement of water
3. State that water moves from an area of low solute concentration (high water concentration) to an area of higher solute concentration (low water concentration)
4. State that this is across a partially permeable membrane
5. State the direction in which the water will move and what you will see in the experiment

Question 15

benefits of using embyonic stem cells

Answer 15

• can treat a wide variety of diseases as cells can differentiate into a much larger number of types of cells compared to adult stem cells
• many are available for use as they are taken from discarded IVF embryos and they would potentially go to waste otherwise
• no pain for donor

Question 16

plasmolysed

Answer 16

the condition of a plant cell when the cytoplasm shrinks away from the cell wall due to water loss

Question 17

factors that affect diffusion

Answer 17

• concentration gradient
• temperature
• (membrane) surface area

Question 18

net

Answer 18

overall movement

some particles might move in different directions but overall movement

Question 19

meristems

Answer 19

unspecialised cells in plants that are capable of differentiating to become any type of specialised cell

found at the tips of their roots and shoots.

Question 20

Which part of the cell membrane shrivels when a plant cell is placed in a concentrated solution ?

Answer 20

cell membrane

Question 21

benefits/risks of using adult animal stem cells

Answer 21

• no ethical issue in collection as permission given
• quick recovery
• relatively safe (doesn not kill donor/low risk)
• well tested

Question 22

hypertonic solution

Answer 22

a solution which is more concentrated than the inside of the cell

Question 23

lysis

Answer 23

the bursting of an animal cell in a hypotonic solution

Question 24

What is a membrane that only allows certain materials to pass through them called?

Answer 24

selectively permeable

Question 25

turgid

Answer 25

when the plant is placed into a dilute solution and takes up water

Question 26

osmosis

Answer 26

the movement of water from a dilute to a more concentrated solution through a partially permeable membrane that allows the passage of water molecules

Question 27

diffusion

Answer 27

the movement of particles from a high to a lower concentration

Question 28

isotonic solution

Answer 28

a solution which is equal in concentration to the inside of the cell

Question 29

problems with embryonic stem cells

Answer 29

- death to embryo - relatively untested - long term effects not known - consent cannot be obtained from the embryo

Question 30

equilibrium

Answer 30

when the concentrations are equal throughout an area or inside and outside a cell

Question 31

crenation

Answer 31

the shrinking of a cell due to osmosis in a hypertonic solution

Question 32

embryonic stem cells

Answer 32

stem cells are only found in embryos that can differentiate into any specialised cell type that make a human ## Footnote allows an embryo to develop a variety of tissues and organs as they develop

Question 33

permeable

Answer 33

allowing certain substances to pass through, such as water or gases.

Question 34

Why is osmosis important in animals?

Answer 34

Osmosis is crucial in animals for maintaining the balance of water and solutes between cells and their environment, ensuring proper cell function.