Cell Biology

Question 1

what is a Prokaryotic cell

Answer 1

a single celled organism which is small and simple e.g bacteria

Question 2

what is a Eukaryotic cell

Answer 2

organisms which are complex e.g all animal and plant cells

Question 3

what is a nucleus

Answer 3

contains genetic material which controls the activities of the cell

Question 4

what is cytoplasm

Answer 4

gel-like substance where most chemical reactions happen and contains enzymes which control these chemical reactions

Question 5

what is a cell membrane

Answer 5

holds the cell together and controls what goes in and out of the cell

Question 6

what is mitochondria

Answer 6

these are where most of the reactions for aerobic respiration takes place.

respiration transfers energy that the cell needs to work

Question 7

what are ribosomes

Answer 7

where proteins are made in the cell

Question 8

what is a cell wall

Answer 8

only in plant cells

made of cellulose - supports and strengthens the cell

Question 9

what is a permanent vacuole

Answer 9

only in plant cells

contains cell sap - a weak solution of sugar and salts

Question 10

what is a chloroplast

Answer 10

only in plant cells

where photosynthesis occurs - makes food for the plant

contains a green substance called chlorophyll which absorbs the light needed for photosynthesis

Question 11

what is the difference between a plant cell and an animal cell

Answer 11

a plant cell has all of the properties an animal cell does however has a cell wall, permanent vacuole and chloroplasts

Question 12

what does a bacteria cell contain and how is it different to plant and animal cells

Answer 12

a bacteria cell doesn’t have a nucleus, it has a strand of DNA instead,

they may also contain one or two plasmids which are small rings of DNA

bacteria has a cytoplasm, cell membrane and cell wall but no chloroplasts or mitochondria

Question 13

what is the difference between a light microscope and an electron microscope

Answer 13

light microscopes use light and lenses to form an image so they let us see individual cells and large subcellular structures

electron microscopes use electrons instead of light to form an image therefore have much higher magnification so a sharper image

Question 14

what is the formula for magnification

Answer 14

image size/real size

Question 15

what is differentiation

Answer 15

process by which a cell changes to become specialised for its job

Question 16

provide some examples of specialised cells

Answer 16

sperm cells are specialised for Reproduction

nerve cells are specialised for rapid signalling

muscle cells are specialised for contraction

root hair cells are specialised for absorbing water and minerals

phloem and xylem cells are specialised for transporting substances

Question 17

what is a chromosome

Answer 17

contain genetic information

body cells normally have two copies of each chromosome one from the mother and one from the father

Question 18

what happens in binary fission

Answer 18

the cell splits in two

Question 19

what are stem cells

Answer 19

stem cells are undifferentiated cells which can be turned into more undifferentiated cells or different types of cells.

Question 20

give an example of where stem cells can be used

Answer 20

can be turned into insulin producing cells for people with diabetes

Question 21

what are the two types of stem cells

Answer 21

1. extracted from bone marrow - turns into red and white blood cells and platelets
2. embryonic stem cells - can be turned into any cell

Question 22

what is diffusion

Answer 22

particles spread out from an area of high concentration to an area of low concentration