B1 cells

Question 1

if the magnification of an eyepiece is x10 and the objective is x40 what is the magnification of the microscope

Answer 1

x400

Question 2

what is one millimetre in standard form

Answer 2

1 × 10^-3 m

Question 3

what is one micrometer in standard form

Answer 3

1 × 10-6 m

Question 4

what is one nanometre un standard

Answer 4

1 × 10-9 m

Question 5

how is standard form written Ax10^n

Answer 5

A is bigger then one but less then 10

Question 6

what would 0.000007 or 7μm be in standard form

Answer 6

7x10^-6

Question 7

what’s the symbol for micrometer

Answer 7

μm

Question 8

what is 1mm in micrometers

Answer 8

1000 μm

Question 9

define the term magnification

Answer 9

The amount that an image of something is scaled up when viewed through a microscope.

Question 10

define resolution

Question 11

how is genetic information stored in the nucleus of a cell

Answer 11

DNA
exists in a cell’s nucleus within structures called
chromosomes
. Each section of a chromosome that contains the code for the production of a particular protein is called a
gene
.

Question 11

What is the difference in order of magnitude for a human hair and HIV?
The width of a human hair is 100 μm, while the width of the HIV is 100 nm.

Answer 11

The difference in order of magnitude is 3.
Calculation:
The width of the human hair is 100 μm = 10-4 m
The width of the HIV is 100 nm = 10-7 m
So, there are three orders of magnitude difference:

Or, more simply:
4 – (-7) = -4 + 7 = 3

Question 11

describe the use of stem cells in production of plant clones

Answer 11

Cells from meristems can be
cloned
. Meristematic cells are removed from a plant and grown in
tissue culture
. The cells are grown in a
culture medium
that contains
agar
– to provide support and water for the growing cells – along with nutrients and
plant hormones
to stimulate growth and cell division.

Question 12

why is plant cloning effective

Answer 12

Producing new plants by cloning is quicker than allowing plants to reproduce and collecting and sowing seeds. It’s therefore an effective way of producing new individuals from rare and endangered plants, helping to preserve the species.

Question 12

how does plant cloning occur naturally

Answer 12

Cloning in plants also occurs naturally, for instance, in
runners in strawberry plants. An older, simpler method of cloning plants that gardeners use to produce new, identical plants is by taking
cuttings

Question 13

what is therapeutic cloning

Answer 13

Using cloning technology for medicinal purposes. One example is to use a person’s DNA to clone one of their organs for use in transplanting.

Question 14

why use stem cell transplants instead of a donor

Answer 14

-Those that use the patient’s own stem cells would be genetically identical
Those from a donor would not be genetically identical. and would not be rejected Fewer complications would arise if the stem cells came from a close member of the family. Alternatively, donor cells could come from a person with closely-matched tissue types. by the patient’s immune system.
-

Question 15

describe therapeutic cloning

Answer 15

Therapeutic cloning
could produce stem cells with the same genetic make-up as the patient.
The technique involves the transfer of the nucleus from a cell of the patient, to an egg cell whose nucleus
has been removed.

Question 16

evaluate benefits and risks of stem cells in medicine (give benefits)

Answer 16

Stem cells have great potential, in treating patients with currently untreatable conditions, growing organs for transplants, and research.

Therapeutic cloning
could produce stem cells with the same genetic makeup and would not be rejected by the patient’s immune system.

Question 17

list clinical issues with stem cells

Answer 17

There is no guarantee how successful these therapies will be

The current difficulty in finding suitable stem cell donors.

Cultured stem cells could be contaminated with viruses which would be transferred to a patient.

Question 18

list ethical issues of stem cells

Answer 18

A source of embryonic stem cells is unused embryos produced by in vitro fertilisation (IVF)

For At what stage of its development should an embryo be regarded as, and treated as a person? therapeutic cloning is it right to create embryos for therapy, and destroy them in the process?

Question 19

describe the digestive systems functions

Answer 19

it has two functions:
breaks down complex food substances
provides the very large surface area for maximum absorption of food

Question 20

mouths function

Answer 20

Begins the digestion of carbohydrates

Question 21

stomachs function

Answer 21

Begins the digestion of protein; small molecules such as alcohol absorbed

Question 22

function of small intestine- duodenum

Answer 22

Continues the digestion of carbohydrate and protein; begins the digestion of lipids

Question 23

small intestine- lleum

Answer 23

Completes the digestion of carbohydrates and proteins into single sugars and amino acids; absorption of single sugars, amino acids and fatty acids and glycerol

Question 24

large intestine

Answer 24

Absorption of water; egestion of undigested food

Question 25

what are digestive enzymes used for

Answer 25

Digestive enzymes are used to break down food in the gut into small, soluble molecules that can be absorbed through the gut wall.

Question 26

how does the digestive system work as an organ system

Answer 26

several organs work together to digest and absorb food

Question 27

what is digestion

Answer 27

a process in which relatively large, insoluble molecules in food (such as starch, proteins) are broken down into smaller, soluble molecules that can be absorbed into the bloodstream and delivered to cells in the body

Question 28

how can the products of digestion be used

Answer 28

Digested molecules can be used to construct new carbohydrates, proteins and lipids in the body. Some glucose produced by digestion is used for respiration.

Question 29

describe how patients can be treated in the case of heart failure

Answer 29

Drugs - statins to prevent build-up of material in arteries Heart transplant to replace a damaged heart Replacement heart valves to improve circulation of blood

Question 30

where is the pacemaker located in the heart

Answer 30

wall of the right atrium

Question 31

what is the only artery of the body to carry deoxygenated blood

Answer 31

the pulmonary artery

Question 32

what is the only vein to carry oxygenated blood

Answer 32

the pulmonary vein

Question 33

what’s the difference between arteries and veins

Answer 33

arteries carry blood away from the heart, veins towards it.

Question 34

evaluate the advantages and disadvantages of drugs to treat heart disease

Answer 34

advantages: -reduce risk of heart attack -used to reduce cholesterol levels that have genetic causes -cheap to administer -may have beneficial effects in other conditions disadvantages: -not suitable for people with liver disease -some side effects -must be taken for life -can’t take if pregnant or breastfeeding

Question 35

evaluate the advantages and disadvantages of heart transplants

Answer 35

advantages: improve quality of life and can be lifesaving disadvantages -few donor hearts are available -recovery time is long -risk of rejection by the body’s immune system -expensive operation and aftercare

Question 36

evaluate the advantages and disadvantages of Replacement heart valves

Answer 36

advantages: restore blood flow through the heart less risk of complications in surgery then transplant disadvantages: -biological values may wear out -blot clots can stick to mechanical valve -anti blood clotting drugs need to be taken which increases risk of further illness

Question 37

what lifestyle changes can be made to prevent heart disease

Answer 37

-cut down on fatty foods- lower blood cholesterol -stop smoking- can effect blood pressure and reduce risk of heart attack -regular exercise -reduce salt in diet to reduce blood pressure

Question 38

what factors to doctors need to consider before choosing treatment of heart disease

Answer 38

the likely effectiveness of the treatment the risk of causing further harm the costs and benefits to both the patient and the health service

Question 39

what are known risk factors for cancer

Answer 39

lifestyle factors: viruses linked with cancer (hpv) being spread through sex chemical carcinogens in cigarettes alcohol intake exposure to uv- which is ionising during sunbathing or outdoor activities-skin cancer diet including fat and salt intake increases risk of cancer environmental: exposure to ionising radiation exposure to chemical carcinogens genetic risk: genetic inheritance

Question 40

how are plant leaves adapted for gas exchange and photosynthesis

Answer 40

large surface area: maximum absorbtion of light for optimum absorption of carbon dioxide air spaces between cells within the leaf air spaces between cells within the leaf: for the diffusion of gases