1.1 Cells

Question 1

Nucleus

Answer 1

Controls activities of cell
contains all genetic information on chromosomes

Question 2

Nuclear membrane

Answer 2

Surrounds nucleus

Question 3

Cytoplasm

Answer 3

Jelly like fluid where most chemical reactions occur

Question 4

Cell Membrane

Answer 4

Selectively permeable - lets some material enter and leave the cell

Question 5

Mitochondria

Answer 5

Organelle for release of energy by aerobic respiration

Question 6

additional features found in plant cells

Answer 6

cell wall
chloroplasts
vacuole

Question 7

Cell wall

Answer 7

Made of cellulose
strengthens and supports cell

Question 8

Chloroplast

Answer 8

Contain chlorophyll needed for trapping light in photosynthesis

Question 9

Vacuole

Answer 9

Contains cell sap - involved in keeping cells rigid

Question 10

using microscope

Answer 10

place thin section of material on slide and cover with cover slip
if stain needed add stain before cover slip
set slide on stage and use the lowest objective lens to have a wide field of view
focus using coarse focusing knob and then fine focusing
iincrease magnification by changing the objective lens

Question 11

dye to stain onion cells

Answer 11

iodine

Question 12

dye to stain cheek cells

Answer 12

methylene blue

Question 13

Why stain cells when looking at them

Answer 13

so you can see parts of the cell more easily

Question 14

How is a bacteria cell different to plant and animal cells

Answer 14

Bacteria cells have
no nucleus - chromosome freee in cytoplasm
Have a circular piece of DNA called plasmid
a non-cellulose cell wall
No membrane bound organelles eg mitochondria

Question 15

How is a bacteria cell similar to animal cell

Answer 15

Has a cell membrane
Has cytoplasm

Question 16

How is a bacteria cell similar to plant cell

Answer 16

Has cell membrane
has cytoplasm
has a cell wall

Question 17

What is a tissue

Answer 17

Made up of same type of cell to do a particular function

Question 18

What is an organ

Answer 18

made up of different types of tissues that do a particular function

Question 19

What is an organ system

Answer 19

Made up of different types of organs that work together to do a particular type of function

Question 20

Name an organ in plant

Answer 20

Leaf
Root

Question 21

What is epithelial tissue

Answer 21

Tissue that lines organs eg stomach

Question 22

How do you calculate magnification

Answer 22

Magnificiation = Image size/actual size

Question 23

How do you calculate Actual size when looking at diagram

Answer 23

Actual size = Image size/magnification
I
M x A

Question 24

What are the differences between light and electron microscope

Answer 24

Electron microscope higher magnification
Electron microscope higher resolution (able to distingush between 2 spots close together)
More expensive

Question 25

What is a stem cell

Answer 25

A simple cell that has the ability to divide to form cells of the same type

Question 26

Name 3 sources of stem cells in animals

Answer 26

embryo umbilical cord bone marrow

Question 27

Why are embryonic stem cells more advantageous to use than adult stem cells

Answer 27

Embryonic stem cells can divide to form a full range of cell types but adult stem cells are limited (blood cells)

Question 28

Where are stem cells found in plants How are plant stem cells better than animal cells

Answer 28

In the meristems (shoot tip and root tip) plant cells retain ability to divide but animal cells do not

Question 29

In treatment of leukaemia stem cells can be used. What happens during pre treatment

Answer 29

Patient treated using chemotherapy and radiotherapy to destroy white blood cells - however increases risk of infection as immune system affected

Question 30

In treatment of leukaemia stem cells can be used. Where do the stem cells come from that are used in treating patient

Answer 30

Stem cells from bone marrow of a donor that is closely matched

Question 31

What are some of the risks to patient being treated for leukaemia

Answer 31

Pre treatment - risk of infection after treatment with chemotherapy and radiotherapy Stem cells may divide uncontrollably and cause othercancers Viruses or disease may be transferred from other animals

Question 32

What is meant by peer review

Answer 32

Process in which other scientists within the same field of study check the work of a scientist to ensure it is valid

Question 33

What is the definition of diffusion

Answer 33

Diffusion is movement of molecules from high to low concentration, down the concentration gradient

Question 34

What factors affect the rate of diffusion

Answer 34

temperature concentration surface area

Question 35

Give an example of where diffusion happens in animals

Answer 35

Lungs - alveoli to blood - have a large surface area and maintain a concentration gradient Blood to cells - glucose and oxygen diffuse into cells down concentration gradient and waste materials diffuse from cells to blood

Question 36

Give an example of diffusion in plants

Answer 36

Diffusion of gases into and out of leaves