Section 1 - The nature and variety of living organisms

Question 1

MRS GREN

Answer 1

• Movement
• Respiration
• Sensitivity
• Growth
• Reproduction
• Excretion
• Nutrition

Question 2

Levels of organisation

Answer 2

• Organelle
• Cell
• Tissue
• Organs
• Organ Systems

Question 3

Animal characteristics

Answer 3

• Eukaryotic
• multicellular
• nervous coordination
• store carbohydrates as glycogen

Question 4

Plants characteristics

Answer 4

• Eukaryotic
• Multicellular
• Have chloroplast for photosynthesis
• Cell walls made of cellulose
• Store carbohydrates as starch/sucrose

Question 5

Fungi characteristics

Answer 5

• Some single-celled (yeast)
• Some have body called mycelium, made up of hyphae that contain lots of nuclei
• cell walls made of chitin
• store carbohydrates as glycogen

Question 6

Animal nutrition

Answer 6

heterotrophic

Question 7

Plant nutrition

Answer 7

Autotrophic

Question 8

Fungi nutrition

Answer 8

Saprotrophic - release extracellular enzymes to dissolve their food + absorve nutrients

Question 9

Protoctists characteristics

Answer 9

• Eukaryotic
• Single-celled
• Some chloroplasts
• Chlorella (plants-like)
• Amoeba (animal-like)

Question 10

Bacteria characteristics

Answer 10

• Prokaryotic
• single-celled
• dont have nucleus
• DNA in circular chromosomes
• Some photosynthesise

Question 11

Viruses Characteristics

Answer 11

• smaller than bacteria
• Only reproduce inside living cells
• Inflect all type of organims
• Have a protein coat around genetic material (DNA or RNA)

Question 12

Organisms that are pathogens

Answer 12

• Fungi
• Protoctists
• Bacteria
• Viruses

Question 13

enzyme def

Answer 13

• biological catalysts produced by living things, usually make a reaction happen more quickly.
• They are proteins that are made up of chains of amino acids

Question 14

Catalyst def

Answer 14

Substance which increases speed of a reaction without being changed or used up in the reaction

Question 15

explain lock & key model

Answer 15

• Enzymes normally speed one reaction
• Because to work, substrate has to be the correct shape to fit the active site of the enzyme

Question 16

Factors affecting enzyme function

Answer 16

• pH
• Temperature

Question 17

enzyme pH

Answer 17

• pH interferes with the bonds that hold the enzyme together
• Optimum pH 7 but not always
• If too high changes the shape of the active site and denatures the enzyme

Question 18

enzyme temperature

Answer 18

• high temp increases the rate. Enzyme and active site move more quickly + more likely to collide
• If too hot bonds holding enzyme together break + change active site. Denatures the enzyme

Question 19

Diffusion def

Answer 19

Net movementof particles from area of higher concentration to area of lower concentration

Question 20

Diffusion characteristics

Answer 20

• Passive process - dosent require energy
• Both liquids and gases use it
  -The bigger the difference in concentration, the faster the diffusion rate

Question 21

Diffusion in cell membranes

Answer 21

YES
small molecules like: glucose, amino acids, water and oxygen

NO
Big molecules like: starch, proteins

Question 22

Osmosis def

Answer 22

net movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration

Question 23

Active transport def

Answer 23

Movement of particles against concentration gradient using energy released during respiration

Question 24

Four factors that affect movement of substances

Answer 24

• surface area to volume ratio
• distance
• temperature
• concentration gradient