3rd Form Definitions And Key Concepts

Question 1

Pathogen

Answer 1

A microorganism that causes a disease

Question 2

Nucleus

Answer 2

-Controls the activity of the cell (by making proteins)
-Contains the chromosomes - strands of DNA which carry the genes (each gene codes for a protein)

Question 3

Cell membrane

Answer 3

-Boundary between the cytoplasm and the cell’s surroundings
-Controls what
substances enter and leave the cell (selectively permeable)

Question 4

Cytoplasm

Answer 4

-Jelly-like liquid where chemical reactions occur

Question 5

Mitochondria

Answer 5

-Carries out some reactions of aerobic respiration, producing ATP (energy
carrier molecule)

Question 6

Ribosomes

Answer 6

-Synthesise (assemble) proteins from amino acids

Question 7

Chloroplasts
ALE,AUITCOCROP/S,MBMFPC

Answer 7

-Absorb light energy and use it to carry out the chemical reactions of photosynthesis, making biological molecules for plant cells

Question 8

Cell wall

Answer 8

-Made of cellulose (a carbohydrate) in plants
-Helps to keep plant cells in a fixed shape (and so keeps the plant upright)

Question 9

Vacuole
F

Answer 9

-Filled with a watery liquid called cell sap
-stores dissolved sugars, mineral ions and other substances.

Question 10

Waxy cuticle
OPLTPWLVE

Answer 10

Outermost protective layer that prevents water loss via evaporation

Question 11

Upper epidermis
TATLOCTALTEPM

Answer 11

Thin and transparent layer of cells to allow light to enter Palisade Mesophyll

Question 12

Palisade mesophyll
LTPWC,TMLAFP/S

Answer 12

Layer tightly packed with Chloroplasts to maximise light absorption for Photosynthesis

Question 13

Lower epidermis

Answer 13

Contains guard cells and stomata

Question 14

Spongy mesophyll
LCIAS TISATVR FTDOG

Answer 14

Layer containing internal air spaces to increases surface area to volume ratio for the diffusion of gases (mainly
Carbon Dioxide)

Question 15

Guard cell
CTC TOACOS BAA LWTRGE

Answer 15

Cells that control the opening and closing of Stomata by absorbing and losing water to regulate gas exchange

Question 16

Stomata
M-SOFAC BGC TRGE APWL

Answer 16

Mouth-shaped opening flanked and controlled by Guard cells to regulate gas exchange and prevent Water loss (via transpiration)

Question 17

Vascular bundle
CXAPTTSTAFTL

Answer 17

Contains xylem and phloem to transport substances to and from the leaf

Question 18

Xylem
TWITL FMCTUIP/S AFTFS

Answer 18

Transports water into the leaf for mesophyll cells to use in photosynthesis and for transpiration from stomata

Question 19

Phloem

Answer 19

Transports sucrose and amino acids around the plants

Question 20

Enzyme

Answer 20

Protein molecule that acts as a biological catalyst by speeding up the rate of specific reaction without being used up or affected

Question 21

Food chains
STFRBLO

Answer 21

Shows the feeding relationships between living organsims

Question 22

Food webs
SHFCALTIMCFR

Answer 22

Shows how food chains are linked together into more complex feeding relationships

Question 23

Pyramids of numbers
STPOEO AETLIAFC

Answer 23

Shows the population of each organisms at each tropic level in a food chain

Question 24

Pyramids of biomass
STB (AOLM) OOIETL

Answer 24

Shows the biomass (amount of living material) of organisms in each trophic level

Question 25

Pyramids of energy transfer

Answer 25

Shows the transfer of energy with each trophic level