Cb2d+CB1h Flashcards
Percentage change in mass=
Final mass-initial mass /initial mass x 100
What are the advantages of using percentile curves to assess growth and development of a young baby
- Ablity to spot a medical problem earlier
- Make sure the baby stays in the correct percentile
- Easily report the points in the baby’s growth that are concerning
What are the disadvantages of using percentile curves to assess growth and development of a young baby
- Only mesuares growth
- Does not diagnose illness
Plant variation is
the variation that we see due to different types
What are specialised cells
Made through differentiation
What are meristem cells
Undifferentiated cells in plants found in the roots
What are palisade cells
- Top of the leaf
- Tall and has a large surface area to catch as much sunlight as possible
- Packed with chloroplasts
What are Root hair cells
- Large surface area to absorb lots of water
- Thin cell wall to allow water to pass through easily
- Doesn’t contain any chloroplasts
What is the Xylem cells
- Xylem vessels consist of dead cells
- Thick, strengthened cell wall with a hollow middle
Functions of palisade cells
Carry out photosynthesis
Function of Xylem cell
Involved in movement of water through the plant
Function of a Root hair cell
Absorbs minerals and water from the soil
Function of the Meristem cell
- Can give rise to any other types of cells
- Found in zones where plant growth takes place e.g shoots and roots
What are stem cells
Undifferentiated cells
What are embroyotic stem cells
Cells found in embryos and can difdertiate into almost every type of human cell
What are adult stem cells
Adult stem cells can only differentiate into a few types of other cells and o ce it has it cannot turn into another type of cell
How does cells become a baby
Mitosis, differentiation, baby
Risks of using stem cells
- Can continue to divide in the body to produce cancer
- Stem cells form another person can be rejected by the patients immune system
A disease that can be treated by stem cells
Cardiovascular disease
Benefits of using stem cells
- Used to replace damaged or diseased cells
- Used for testing new drugs before they are tried on people
- Can be studied to show how some cells become damaged, so that new treatments can be developed
List the different parts of the brain
Hypothalamus, Spinal cord, Medulla oblongata, Cerebellum, Cerebral hemispheres/ cortex
What does the spinal cord do
Make up the CNS
What does the Medulla oblongata do
Controls heart beat, movements of the gut and breathing
What does the Cerebellum do
Control coordinated muscular activity and balance
What does the Cerebral hemispheres/ cortex do
Controls consciousness, intelligence, memory and language
What are the stages of the cell cycle
Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
What happens during Interphase
The cell spends most of its life in this phase. The DNA in chromosomes copies itself ready for mitosis.
What happens during Prophase
The DNA in chromosomes and their copies condenses to become more visible. The membrane around the nucleus disappears.
What happens during Metaphase
Chromosomes and their copies line up in the middle of the cell.
What happens during Anaphase
Chromosomes and their copies are pulled to different ends of the cell.
What happens during Telophase
New membranes form around the chromosomes at each end of the cell.
What happens during Cytokinesis
The cell membrane pinches in and eventually divides into two daughter cells.
Describe how brain tumours can be treated.
Brian tumors can be treated by radio therapy, chemotherapy (cancerous) and surgery (non cancerous). This is in hope to control the abnormal growth in cells as they divide in an uncontrollable way.
What is a PET scan
Gamma rays are detected as a position from a radioactive substance in your body annihilates an electron into the patients body producing a 3D image of the body
What is a CT scan
The X-rays are detected and are used to reduce and image of a thin slice of the brain on a computer screen in which the different soft tissues of the brain can be distinguished.
Explain the advantages of using a PET scanner
Only takes half an hour, little recovery time and can differentiate between cancerous and non cancerous.
Explain the advantages of using a CT scanner
Used to detect and manage brain disease during illness
Explain the disadvantages of using a PET scanner
- Pregnant women cannot use it
- Diabetics can only undergo with precautions
- Limited number of times someone can have this scan due to radioactivity
Explain the disadvantages of using a CT scanner
- Frozen movement pictures
- Examine structures not functions
- X rays can be harmful
- Patient needs to remains still otherwise blurry image
What are receptor cells
Cells in organs that detect changes in the surroundings (a stimulus)
What is the order of the nervous system
Stimulus –> Impulse starts at receptors –> impulse passed along sensory neurone –> Impulse travels to CNS –> Impulse passed along motor neuron –> Effector receives impulse to react –> Response
Features of a sensory neuron
Axon, Dendron, Axon terminal, Dendrites, Cell body, Myelin sheath
What do sensory neurones do
Carry impulses from the receptor to the CNS
What are relay neurones
- Short neurones found in the spinal cord, linking sensory and motor neurones as well as making up nerve tissue in the brain
- No dendrons so dendrites are on the cell body
What do motor neurones do
- Carry impulses to effectors
- No dendrons so dendrites are on the cell bodyj
What are synapses
- Where neurones meet each other which contains a tiny gap
- They slow down transmission speed
What is the stages of an impulse travelling through a synapse
- Electrical impulses reach the end of the neuron (axon terminal)
- It is then transferred to be a chemical (neurotransmitter), when it is between the axon and dendrite
- The neurotransmitter binds with a receptor before continuing through to the next neurone as a new impulse has been generated.
List the parts of the eye
Lens, Cornea, Ciliary muscles, Iris, Optic nerve, Retina, Rods and Cones
Function of the lens
Focuses light on the retina
Function of the cornea
Found on the outer surface focusing the light on the retina
Function of the Pupil
Where the light enters in the dark area
Function of the Ciliary muscles
Changes the shape of the lens for fine recording
Function of the Iris
Muscles in the Iris control the amount of light entering the eye by constricting or dilating the pupil
Function of the Rods and Cones
Receptor cells at the back of your eye. The cones are for detecting colour in light. The rods detect the light intensity.
Function of the Optic Nerve
Neurones that carry nerve impulses from rods and cones to the brain
How to correct cataracts
Replacing the old clouded lens with a plastic one
How to correct colour blindness
Cannot be corrected
Why are people short sighted, what do they see and how do you correct it
Distant objects are blurry due to the eyeball being too long or the lens not being able to get thin enough. This can be corrected by using a diverging lens to change the light focus point or laser surgery to reshape the cornea
Why are people long sighted, what do they see and how do you correct it
Close objects are blurry due to the eyeball being too short or the cornea not being curved enough. This can be corrected by using a converging lens to change the light focus point or laser surgery to reshape the cornea.
Growth is…
an increase in the number of cells in an organism
Growth can be measured by
length, height, mass ect
What is the cytoplasm of fat cells
Filled with large fat droplets stored until the body needs energy
