Cells

Question 1

What is a cell

Answer 1

Basic building block of all living organisms.

Question 2

What is the function of a cell membrane

Answer 2

Forms a boundary to the cell and is selectively permeable, controlling what enters and leaves

Question 3

Function of cytoplasm

Answer 3

Site of chemical reactions

Question 4

Function of nucleus

Answer 4

Control centre, containing genetic information in the form of chromosomes

Question 5

Function of nuclear membrane

Answer 5

Controls what enters and leaves nucleus, boundary

Question 6

Function of mitochondria

Answer 6

Site of cell respiration

Question 7

Function of a vacuole

Answer 7

Contains cell sap and provides support

Question 8

Function of chloroplasts

Answer 8

Contain chlorophyll and place where photosynthesis takes place

Question 9

Function of plasmids

Answer 9

Small circular rings of DNA

Question 10

How to make a slide of plant cells

Answer 10

-peel small section of onion tissue and place on centre of microscope slide

• add water using a drop pipette to the onion tissue to stop it drying out
• gently lower a coverslip onto onion cell. Cover slip will protect the lens if it should make contact with the slide, and prevents cell drying out
• set slide onto stage of the microscope. And examine using low power first and then high power

Question 11

How to make a slide for animal cells

Answer 11

• using your nail gently inside of your cheek
• smear material gathered into centre of microscope slide
• carefully lower cover slip on top to protect the lens if it should make contact with slide and to prevent cell from drying out
• observe using a light microscope; first at low power and then high power

Question 12

Why should you always start examining on low power

Answer 12

Greater field of view and easier to focus at low than high

Question 13

Triangle for magnification

Answer 13

I

A. M

Question 14

What does the triangle I. STAND FOR
A. M

Answer 14

Image

Actual size

Magnification

Question 15

Standard form of a millimetre in metres

Answer 15

-3
10. M

Question 16

Standard form for a micro metre in metres and millimetres a

Answer 16

-6
10. M

   -3.    10.         Mm

Question 17

How many millimetres in a metre

Answer 17

1000

Question 18

How many micro metres in a millimetre and therefore metre

Answer 18

1000 in a mm

1 000 000 in a m

Question 19

What is a electron microscope

Answer 19

Beams of electrons through a specimen rather than light beams to form a image, allows a greater resolution

Question 20

What is resolution

Answer 20

Describes the Ability of a microscope to preserve detail when magnifying. Resolution is the ability to see two separate points as distinct entities

Question 21

Two advantages of electron microscopes

Answer 21

See structures we previously weren’t aware of

See internal detail of cell structures like nucleus or chloroplasts

Question 22

What is a stem cell

Answer 22

Cells that have the ability to divide and produce different types of cell

Question 23

What are the two types of stem cells in animals

Answer 23

Adult and Embryonic

Question 24

What are adult stem cells

Answer 24

Stem cells that can divide to form cells of the same general type

Eg: bone marrow cells can only form different types of blood cells

Question 25

What are embryonic stem cells

Answer 25

Stem cells that form embryos or the umbilical cord can form a full range of cells in the body

Question 26

After a number of divisions of animal cells what happens

Answer 26

They become specialised cells which are adapted for particular functions

Question 27

Where do stem cells originate in plants

Answer 27

Meristems at root apices and shoot apices or tips

Question 28

How can bone marrow stem cells be used to treat leukaemia

Answer 28

Bone marrow transplants have the ability to produce different types of blood cells in the right proportions. (Which doesn’t happen if you have leukaemia)

Question 29

Benefits of stem cells in medicine

Answer 29

Diseases such as leukaemia can be treated Replacement of body parts including replacement organs

Question 30

Risks or ethical considerations on stem cells in medicine

Answer 30

Leukaemia pre treatment can involve radio or chemotherapy which can kill healthy cells as well The transfer of viruses or diseases from other animals Formation of tumours or the development of unwanted cell types

Question 31

What has to be done to stem cell research

Answer 31

Peer review

Question 32

What is diffusion

Answer 32

Movement of molecules from a region of high concentration to low concentration

Question 33

How does temperature affect diffusion

Answer 33

The higher the temperature, the faster the diffusion due to greater kinetic energy of the molecules

Question 34

How does surface area affect the rate of diffusion

Answer 34

The greater the surface area the faster the rate if diffusion as more area over which diffusion can occur

Question 35

How does the concentration affect the rate of diffusion

Answer 35

The greater the gradient the greater the rate of diffusion

Question 36

What is a tissue

Answer 36

Groups of cells with similar structures and functions

Question 37

What is a organ

Answer 37

Groups of different tissues working together to form a structure with a particular function

Question 38

What is a organ system

Answer 38

Organs organised into organ systems

Question 39

What is a organism

Answer 39

Different organ systems make up a organism

Question 40

As organisms get larger what happens

Answer 40

The surface area to volume ratio decreases

Question 41

What is the consequence of organisms getting larger and the surface area to volume ratio decreasing

Answer 41

Means organisms need to increase the surface area across which molecules can diffuse, they do this through specialised exchange surfaces eg : lungs and gills

Question 42

One reason why people might be ethically against to stem cells

Answer 42

Designer babies