Topic 2- Cells And Control Flashcards Preview

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Flashcards in Topic 2- Cells And Control Deck (61):
1

Ordered phases of human growth

1. Infancy
2. Childhood
3. Adolescence
4. Maturity
5. Old age

2

Mitosis is...

The process of cells dividing to produce two genetically identical daughter cells to the parent.

3

Interphase is...

Where DNA and other sub cellular structures are replicated
Chromosomes are copied

4

The two biological processes that take place in interphase are...

Protein-synthesis and respiration

5

Prophase is...

The stage which the nuclei start to break down and spindle fibres appear

6

Metaphase is...

The chromosomes lining up across the middle of the cell

7

Anaphase is...

The chromosomes are separated and pulled apart from each other by spindle fibres

8

Telophase is...

Chromosomes reach the opposite sides of the cell and the nucleus membrane reforms

9

Cytokinesis is...

The cytoplasm of the cell is separated as the cell membrane is pinched to divide the cell into two two genetically identical daughter cells

10

Spindle fibres are...

A filament formed in a cell during mitosis which helps to spectate chromosomes

11

Advantages to percentile curves

Easy to understand how growth is going
The data is in order
You know what values are greater and less than the babies growth

12

Disadvantages of percentile curves

The averages can be misleading
Difficult to see weakly development
If there were any problems you would only notice after a month

13

Raise of concern for health professions when looking at percentile curves

Data greater than 99.6th percentile curve
Data less than 0.4th percentile curve
Data that doesn’t follow a percentile curve

14

Cell differentiation is...

The process by which a cell changes to become specialised for it’s job to work more effectively for a specific function

15

How the fat cell is specialised

Large surface area
Small nucleus for more fat to be stored in the cytoplasm of the fat cell

16

Function of the fat cell

The fat is stored until the body needs energy
Acts as a reserve

17

How is the red blood cell specialised

No nucleus and biconcave shape to increase surface area
Large surface area for more oxygen to be transported and faster gaseous exchange
More space for haemoglobin (pigment which combines with oxygen)

18

The function of the red blood cell

To transport oxygen through the blood
To allow more oxygen to be transported

19

Cells that are differentiated are...

Highly adapted to their function

20

Cell division is...

The process of mitosis which means it grows, repairs and reproduce cells.
To produce two genetically identical daughter cells

21

Three stages of growth in a plant in order

Firstly...Cell division
Secondly...Cell elongation
Thirdly...Cell differentiation

22

How plants grow

Cells found in an area called the meristems (in shoots and roots) go through cell division- mitosis which produces more genetically identical cells in a rapid way
The cells then increase in length this is called elongation
Cells can then differentiate into specialised cells

23

Embryonic stem cells

Inner cell layers of a blastocyst
Pluripotent cells... can differentiate into many cells
Can differentiate into nearly all cell types the new baby will need
Eg. Blood, nerve and bone cells ect.

24

Animal adult stem cells

Found in the bone marrow, adipose tissue and blood
Multipotent cell... can differentiate into a few cells
Maintain and repair the tissue in which they are found
Differentiate into similar cells from the tissue the adult stem cells cake from

25

Plant stem cells

Found in the meristem
Totipotent cells... can differentiate into all cells
Can differentiate into any new specialised cells
Maintain the stem cell number by self-renewing

26

Benefits of stem cell use in medicine

Can be successfully transplanted into recipients
Can be reprogrammed to differentiate into a different cell which is transplanted into recipient to treat damaged or diseased tissue
Tested on for new drugs before tried on people
Can be studied to show how some cells become damaged eg. Parkinson’s (to help find a treatment)
Used to replace damaged or diseased cells
Stem cells from a persons body will not be rejected because they are recognised as ‘self’

27

Risks of using stem cells in medicine

Reprogrammed stem cells may not carry out the correct function, may continue to divide uncontrollably and become cancerous cells that form tumours
Stem cells from another person may be rejected by the patients immune system

28

A neutron is...

A structure which contains a nerve cell body and other sub-cellular structures to carry an impulse

29

CNS is...

Central Nervous System

30

PNS is...

Peripheral Nervous System

31

A stimulus is...

A type of energy detected by a receptor

32

List the five receptor organs

Tongue, ears, eyes, skin and nose

33

Order of neurones

Sensory neurone- linking the receptor to the co-ordinator
Relay neurone- within the co-ordinator/ CNS/ brain or spinal cord
Motor neurone- linking the co-ordinator to the effector

34

Examples of an effector

Muscle or gland

35

Reflex arc...

1.Stimulus
2. Receptor
...(sensory neurone)...
3. Co-ordinator ...(relay neurone)...
...(motor neurone)...
4. Effector
5. Response

36

When an impulse reaches a synapse...

The chemicals (neurotransmitters) diffuse across the synaptic cleft and bind with receptors on the next neurone, triggering another impulse

37

Myelin...

Makes the impulse through a neurone travel faster

38

Iris

Controls the amount of light entering the eye

39

Pupil

A hole in the front of the eye for light to pass through

40

Cornea

Refracts light entering the eye

41

Lens

Focuses light on the retina

42

Retina

Detects light

43

Optic nerve

Carries nerve impulses to the brain

44

Sclera

Protective white leathery outer layer which provides attachment points for ocular muscles and maintains the shape of the eye

45

Rods are...

More sensitive in dim light
Can’t see colour

46

Cones are...

Sensitive in millions of different colours
Not very good in dim light

47

Describe colour blindness

Eye can’t distinguish between two colours
Most common is red-green colours this will be because red or green comes are damaged

48

Explain how colour blindness is corrected

Because cones are damaged and the come cells can’t be replaced therefore meaning there isn’t a cure yet
Scientists are developing and improving ways like injections, lens and glasses

49

Describe cataracts

Cloudy patch in the eye which stops light being able to enter
Therefore blurring the vision , less vivid vision and a struggle to see to see bright

50

Explain how cataracts are corrected

Because of the faulty lens not working, it will be replaced with an artificial lens

51

Describe long sightedness

Eye ball is too short
Doesn’t refract light enough
Not able to focus near objects
Can focus on distant objects

52

Explain how long sightedness is corrected

Because the image is focused behind the retina a convex lens is needed

53

Describe short sightedness

Eye ball is too long
Refracts light too much
Can focus near objects
Can’t focus distant objects

54

Explain how short sightedness can be corrected

Because the image is focused in front of the retina, a concave lens is needed

55

Near objects cause...

Ciliary muscles to contract
Suspensory ligaments to slacken
Appearance of lens to be thicker and more rounded

56

Distant objects cause...

Ciliary muscles to relax
Suspensory ligaments to tighten
Appearance of lens to be thinner and less rounded

57

Describe the function and structure of the cerebral hemispheres

Split into two hemispheres
Left side of the the brain will control the right side of your body and vice verse
The cerebrum controls memory, speech, senses, language and vision

58

Describe the structure and function of the cerebellum

Two folded and grooved halves
Controls co-ordination for movements, posture and co-ordination for muscles.
Means little brain because it looks like a small brain

59

Describe the structure and function of the medulla oblongata

Found at lowest part of brain stem next to the spinal cord
Controls unconscious activities like heart rate, blood vessel control, blood pressure and breathing
Reflexes that are not thought about

60

CT scans

Used for head injuries, severe headaches, dizziness, strokes, brain tumours and bleeding.
Special x-ray equipment to show series of slices of images
Will show up the main structures of the brain not the function
Can detect tumours

61

PET Scans

Used for diseased or injured brain
Uses a tracer, radioactive glucose which will decay quickly, works by how active a cell is because the more active a cell the more glucose will be taken in
Show how the brain works and tissue in the brain
Shows unusually inactive areas which can find out any problems
Eg. Alzheimer’s disease