Cell biology

Question 1

Describe eukaryotic cells

Answer 1

have a nucleus and include animal and plant cell

Question 2

Describe cell membrane

Answer 2

controls the movement of substances into and out of a cell

Question 3

Describe cytoplasm

Answer 3

jelly like substance where reactions take place inside a cell

Question 4

Describe respiration

Answer 4

releases energy and takes place inside mitochondria in cells

Question 5

Where are proteins made

Answer 5

inside ribosomes in cells

Question 6

Describe cell walls

Answer 6

Made of cellulose and give a cell structure.

Question 7

Describe vacuole

Answer 7

Stores cell sap and gives a cell structure

Question 8

Describe chloroplasts

Answer 8

Contain chlorophyll used for photosynthesis

Question 9

Describe chlorophyll

Answer 9

absorbs light for photosynthesis

Question 10

Where is genetic material stored?

Answer 10

On chromosomes held in the nucleus of a cell

Question 11

Describe prokaryotic cells

Answer 11

Bacteria cells, have a cell membrane and cytoplasm but no nucleus

Question 12

Describe the process of a cell becoming specialised

Answer 12

As a cell differentiates it develops different sub-cellular structures to enable it to carry out a particular function, it has become a specialised cell

Question 13

How are sperm cells specialised

Answer 13

Specialised for energy production with a large number of mitochondria

Question 14

How are mesophyll cells are specialised

Answer 14

Specialised for photosynthesis with a large number of chloroplasts

Question 15

When do animal cells differentiate

Answer 15

an early stage of life

Question 16

When do plant cells differentiate

Answer 16

throughout their life

Question 17

Magnification equation

Answer 17

Magnification = image size ÷ actual size

Question 18

What are the microscopy units

Answer 18

µm = micrometre
nm = nanometre
1mm = 1000 µm

Question 19

Which microscope was developed first

Answer 19

light

Question 20

Describe electron microscopes

Answer 20

give greater magnification and resolution, allow people to see more subcellular structures and develop
understanding of them

Question 21

What is mitsosis

Answer 21

Mitosis allows cells to divide for growth, repair and development of an embryo

Question 22

Describe the three stage cell cycle

Answer 22

a) Stage 1 – DNA is copied & number of subcellular structures, mitochondria & ribosomes are increased
b) Stage 2 – chromosomes are pulled to either end of the cell and nucleus divides
c) Stage 3 – cytoplasm and cell membranes divide to form 2 genetically identical cells

Question 23

Describe stem cells

Answer 23

undifferentiated cells found in embryos, adult animals and meristems in plants

Question 24

Describe stem cells from human embryos

Answer 24

can be cloned and made to differentiate into most
different types of human cells

Question 25

Describe stem cells in plants

Answer 25

can be used to produce clones of plants quickly and economically

Question 26

Treatment with stem cells

Answer 26

can be used to help diabetes and paralysis

Question 27

Stem cells risks

Answer 27

transfer of viral infection, religious and ethical objections about killing a potential human life

Question 28

Describe diffusion

Answer 28

the passive movement of particles from a high concentration to a low concentration

Question 29

How can the rate of diffusion be changed

Answer 29

altering concentration gradient, temperature and surface area

Question 30

What are specialised in multicellular organisms?

Answer 30

surfaces and organ systems for exchanging material

Question 31

How is the effectiveness of an exchange surface increased?

Answer 31

1. Having a large surface area 2. Thin membrane 3. Efficient blood supply (in animals) 4. Being ventilated (in animals for gas exchange)

Question 32

Describe osmosis

Answer 32

the passive movement of water from an area of higher water concentration to an area of lower water concentration, across a partially permeable membrane

Question 33

What causes mass changes

Answer 33

the movement of water across a plant cell membrane

Question 34

Describe active transport

Answer 34

uses energy from respiration, to transport substances across a membrane from low concentration to high concentration

Question 35

Where is active transport used?

Answer 35

root hair cells and the small intestine for the absorption of nutrients