B1 cell structure

Question 1

light vs electron microscope

Answer 1

light- up to x2000

electron- up to x2000000

Question 2

magnification=

Answer 2

size of image/ size of real object

Question 3

components of an animal cell

Answer 3

nucleus, cytoplasm, cell membrane, mitochondria,ribosomes

Question 4

plant cells

Answer 4

nucleus, cytoplasm, cell membrane, mitochondria,ribosomes + cell wall ( chloroplasts, permanent vacuole)

Question 5

eukaryotic cells

Answer 5

cell membrane, cell wall cytoplasm and genetic material enclosed in a nucleus

Question 6

prokaryotic cells

Answer 6

cytoplasm and cell membrane surrounded by cell wall
genetic material not in nucleus
forms a single DNA loop
may contain one or more extra rings of DNA called plasmids (all bacteria are prokaryotes)

Question 7

nerve cell adaptations

Answer 7

• axon that carries nerve impulse

- dendrites make connections to other nerve cells

Question 8

muscle cell adaptations

Answer 8

• contain proteins that slide over each other to make fibres contract
• many mitochondria for chemical reactions
• store glycogen which can be broken down and used in cellular respiration

Question 9

sperm cell adaptations

Answer 9

• long tail to help it move
• mitochondria for energy needed to make tail work
• acrosome stores digestive enzymes to break down outer layers of egg
• large nucleus for genetic info to be passed on

Question 10

root hair cell function/ adaptations

Answer 10

• increase SA for water to move into cell
• permanent vacuole speeds up movement of water by osmosis
• mitochondria for energy for active transport of mineral ions

Question 11

photosynthetic cells

Answer 11

chloroplasts to trap light for photosynthesis
positioned in leaves and outer stem to absorb optimal light
large perm vacuole keep cell rigid

Question 12

xylem cells

Answer 12

• lignin build up in cell walls and die to form hollow tubes to allow water and mineral ion movement
• lignin strong to withstand pressure of water movement

Question 13

phloem

Answer 13

• cell walls break down forming sieve plates

- mitochondria of companion cells transfer energy to move dissolved food up and down

Question 14

diffusion definition

Answer 14

spreading out of particles of a substance from an area of high concentration to an area of low concentration, down a concentration gradient

Question 15

factors affecting rate of diffusion

Answer 15

difference in concentrations
temperature
SA available

Question 16

osmosis definition

Answer 16

movement of water from a dilute to a concentrated solution through a partially permeable membrane

Question 17

why is osmosis important in plant cells

Answer 17

allows them to stay turgid

Question 18

active transport definition

Answer 18

movement of substance from a dilute to concentrated solution ( against a concentration gradient)

Question 19

where does the energy come from for AT

Answer 19

energy from food released in respiration

Question 20

features of exchange surfaces

Answer 20

large SA
thin walls (short diffusion pathway)
efficient blood supply
(ventilation for gaseous exchange)