B1 Cell biology

Question 1

Eukaryotic Cells

Answer 1

They have DNA that forms chromosomes which are contained in a nucleus. E.g. Plant and Animal Cells- made of multiple cells

Question 2

Prokaryotic Cells

Answer 2

• single-celled
• no nucleus, one loop of DNA
• have small rings of DNA called plasmids
• smaller than eukaryotic cells

Question 3

mitochondria

Answer 3

THE POWERREALISER OF THE CELL

where energy is released through respiration in the form of ATP

Question 4

cell membrane

Answer 4

controls the movement of substances in and out of the cell: a semi permeable membrane

Question 5

ribosomes

Answer 5

site of protein synthesis

Question 6

cytoplasm

Answer 6

jelly-like substance where chemical reactions happen

Question 7

permanent vacuole

Answer 7

contains cell sap

not in animal cell

Question 8

chloroplasts

Answer 8

contains chlorophyll (a green pigment) to absorb light energy for photosynthesis
not in animal cell

Question 9

cell wall

Answer 9

made of cellulose which strengthens and supports the cell

not in animal cell

Question 10

flagellum

Answer 10

used by bacteria and sperm for movement

Tail like structure

Question 11

sperm cell

Answer 11

fertilises an ovum (egg)
flagellum to swim to the ovum
lots of mitochondria for energy and respiration enables the sperm to swim

Question 12

electron microscope

Answer 12

uses a beam of electrons to form photos
samples can't be living
expensive
high magnification
high resolution

Question 13

light microscope

Answer 13

uses light to form images
living samples can be used
relatively cheap
low magnification
low resolution

Question 14

red blood cell

Answer 14

transports oxygen around the body
no nucleus for room to carry more oxygen
contains haemoglobin (red pigment)that binds to oxygen molecules
flat bi-concave disc shape to increase surface area to volume ratio

Question 15

muscle cells

Answer 15

contract and relax to allow movement
contains protein fibres which contract to make the cells shorter
contains lots of mitochondria to release energy for respiration for contraction

Question 16

nerve cells

Answer 16

carry electrical impulses around the body
branched endings called dendrites allow connections to other neurones and effectors
the myelin sheath insulates the axon to increase the transmission speed of electrical impulses

Question 17

root hair cells

Answer 17

absorb mineral ions and water from the soil
long projection speeds up the absorption of water and mineral ions by increasing the surface area of the cell
lots of mitochondria for the energy released to be used for the active transport of mineral ions

Question 18

palisade cells

Answer 18

enables photosynthesis in the leaf
lots of chloroplasts containing chlorophyll to absorb light energy located on the top surface of the leaf where it can absorb the most light energy from the sun.