cell biology

Question 1

what structures do all eukaryotic cells have? (3)

Answer 1

cell membrane
cytoplasm
nucleus

Question 2

what structures do all prokaryotic cells have? (4)

Answer 2

cytoplasm
cell membrane
cell wall
Plasmids

Question 3

what are plasmids?

Answer 3

a single DNA loop of 1 or more small rings found in prokaryotic cells

Question 4

structures found In animal cells (5):

Answer 4

nucleus
cytoplasm
cell membrane
mitochondria
ribosomes

Question 5

structures found in plant cells (8):

Answer 5

nucleus
cytoplasm
cell membrane
mitochondria
ribosomes
chloroplast
permanent vacuole
cell wall

Question 6

how are sperm cells designed for their job?

Answer 6

have lots of mitochondria in their tails to help them swim

Question 7

how are nerve cells designed for their job?

Answer 7

it’s long for sending messages around the body

Question 8

how are muscle cells designed for their job?

Answer 8

they can shorten to be able to move bones

Question 9

how are root hair cells designed for their job?

Answer 9

have large surface areas so that they can absorb lots of water

Question 10

how is xylem tissue designed for their job?

Answer 10

xylem are dead tubes able to carry water up the stems of plants

Question 11

how is phloem tissue designed for their job?

Answer 11

phloem cells are living tubes able to carry minerals around the plant

Question 12

what’s cell differentiation?

Answer 12

when cells change to form different types of cells

Question 13

when do animals cells differentiate?

Answer 13

at an early stage of growth

Question 14

when do plant cells differentiate?

Answer 14

throughout life

Question 15

why do cells divide in animal cells?

Answer 15

to repair and replace old cells

Question 16

what are cells called once they’ve differentiated?

Answer 16

specialised cells

Question 17

which type of microscope is better? electron vs light

Answer 17

electron microscope

Question 18

why are electron microscopes good?

Answer 18

it has has a higher magnification and resolving power. and studies cells in much finer detail

Question 19

magnification equation:

Answer 19

magnification=size of image➗size of object

Question 20

the process of mitosis (5 steps)

Answer 20

1. genetic material x2 then ÷2 into two identical cells
2. increase in number of ribosomes and mitochondria
3. DNA replicates to make two copies of each chromosome
4. one set of chromosomes is pulled to each end of the cell and the nucleus divides
5. the cytoplasm and cell membranes ÷ to form 2 identical cells

Question 21

why is mitosis important?

Answer 21

it makes multicellular organisms grow and develop

Question 22

What is a stem cell?

Answer 22

An undifferentiated cell

Question 23

What happens to stem cells from human embryos?

Answer 23

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

Question 24

what treatment can stem cells help treatment with? (2)

Answer 24

diabetes
paralysis

Question 25

risks of stems cells (2)

Answer 25

Viral infection
ethnical or religious rejections

Question 26

What’s meristem tissue?

Answer 26

A tissue in plants that can differentiate into any type of plant cell throughout the life of the plant

Question 27

what can therapeutic cloning do?

Answer 27

produce stem cells with the same genetic makeup as the patient

Question 28

why is cloning good for plants?

Answer 28

it can save rare species from going extinct

Question 29

why is cloning good for farmers?

Answer 29

Create large numbers of identical plants for crops

Question 30

what’s diffusion?

Answer 30

The movement of particles from an area of higher concentration to an area of lower concentration

Question 31

what do cells use diffusion for?

Answer 31

oxygen an carbon dioxide in gas exchange

Question 32

What affect the rate of diffusion? (3)

Answer 32

1. The difference in concentration 2. the temperature
2. the surface area of the membrane

Question 33

how can single celled organisms diffuse?

Answer 33

due to their large surface area to volume ratio

Question 34

what affects rate of diffusion in animals? (2)

Answer 34

1. large surface area
2. a membrane that’s think, to provide a short diffusion path

Question 35

what’s osmosis?

Answer 35

The diffusion of water from a low concentrated solution to a high concentrated solution through a partially permeable membrane

Question 36

what does active transport do?

Answer 36

Moves substances from a low concentration to high concentration solution

Question 37

where does the engird come from for active transport?

Answer 37

respiration

Question 38

why is active transport important for plants?

Answer 38

It allows mineral irons to be absorbed into plant root hairs from very dilute solutions in the soil

Question 39

why do plants need ions?

Answer 39

for healthy growth

Question 40

Why does active transport get used in the gut?

Answer 40

It allows sugar molecules to be absorbed from low concentrations in the gut into the blood which has a higher concentration

Question 41

what do sugar molecules get used for?

Answer 41

cell respiration