Topic 2- Cells And Control Flashcards Preview

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

Ordered phases of human growth

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


Mitosis is...

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


Interphase is...

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


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

Protein-synthesis and respiration


Prophase is...

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


Metaphase is...

The chromosomes lining up across the middle of the cell


Anaphase is...

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


Telophase is...

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


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


Spindle fibres are...

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


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


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


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


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


How the fat cell is specialised

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


Function of the fat cell

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


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)


The function of the red blood cell

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


Cells that are differentiated are...

Highly adapted to their function


Cell division is...

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


Three stages of growth in a plant in order

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


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


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.


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


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


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’


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


A neutron is...

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


CNS is...

Central Nervous System


PNS is...

Peripheral Nervous System


A stimulus is...

A type of energy detected by a receptor


List the five receptor organs

Tongue, ears, eyes, skin and nose


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


Examples of an effector

Muscle or gland


Reflex arc...

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


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



Makes the impulse through a neurone travel faster



Controls the amount of light entering the eye



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



Refracts light entering the eye



Focuses light on the retina



Detects light


Optic nerve

Carries nerve impulses to the brain



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


Rods are...

More sensitive in dim light
Can’t see colour


Cones are...

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


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


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


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


Explain how cataracts are corrected

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


Describe long sightedness

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


Explain how long sightedness is corrected

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


Describe short sightedness

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


Explain how short sightedness can be corrected

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


Near objects cause...

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


Distant objects cause...

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


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


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


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


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


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