topic 2 - cells and control Flashcards
What is mitosis
Cell division
All the stages of mitosis and their procedures
Interphase – the cell grow to increase the mass of subcellular structures and duplicate its DNA
Prophase – the chromosomes condense, getting shorter and fatter. The membrane around the nucleus breakdown and the chromosomes.
Metaphase – the chromosomes lineup at the centre of
Anaphase – spindle fibres pull the chromosomes apart then the chromatids are pulled to opposite end of the
Telophase – membranes form around each sets of the chromosomes. These become the nuclei of the two new cells – the nucleus has divided.
Cytokinesis – the cytoplasm and cell membrane divide to form two separate cells
What does mitosis make?
Two genetically identical daughter cells
Why is mitosis important in growth, repair and asexual reproduction
To create new life or make the cell bigger
What is mitosis
Division of a cell by mitosis as the production of two daughter cells, each of identical sets of chromosomes in the nucleus to the parent cell, and that this results in the formation of two genetically identical diploid body cells
What does cancer resulting?
Changes and cells that lead to an uncontrolled cell division
What is cell division and differentiation in animals?
Cell differentiation is when a cell changes to become specialised for a job
cell division is by mitosis
What is cell division, differentiation and elongation in plants?
Cell differentiation is the process by which a cell changes to become specialised for job
Cell division is by mi
Cell elongation is where a plant cell expands, making the cell bigger and so making the plant grow
What’s the function of embryonic stem cells?
They have the potential to divide and produce any kind of salt at all. There really important in growth and development of organisms.
What is the function of meristems in plants?
They produce on specialised cells that are able to divide inform any cell type in the plant – they act like embryonic stem cells. But unlike human stem cells, the cells can divide in differentiate to generate any type of self for as long as the plant lives.
What are benefits of using stem cells in medicine?
It can cure some disease diseases, i.e. sickle cell anemia with bone marrow transplant
What are risks associated with use of stem cells and medicine?
Tumour development – may divide uncontrollably
Rejection – the body can reject
It’s unethical – each embryo is a potential human life
The function of the central nervous system
The nervous system is made of neurons which go to all parts of the body
When the stimulus is detected by receptors, the information is converted to a nervous impulse and sent along sensory neurones to the CNS
The CNS coordinates the response. Impulses travel through the CNS along relay neurones
The CNS send information to an effect a motor neurone. The effector then responds accordingly
What is a sensory neuron made of?
One long dingdong carries nerve impulses from receptor cell cell body, which is located in the middle of a neurone
One short axon carries nerve impulses from the cell body to the CNS
What is a motor neuron made of?
Many short dendrites carrying nerve impulses from the CNS to the cell body
One long axon carries nerve impulses from the cell body to the effector cells
What is the relay neuron made of?
Many short dendrites carrying nerve impulses from sensory neurons to the cell body
And axon carries nerve impulses from the cell body to motor neurons
What is a synapse?
The connection between two neurons is called a synapse
The nerve signal is transferred by chemicals called neurotransmitters which diffuse across the gap
The neurotransmitter is then set up a new electrical signal in the next new
The transmission of a nervous impulse is very fast but is slow down a bit at the signups because the diffusion of neurotransmitters across the gap takes time
What are differences between series and parallel circuits
SERIES
if you disconnect one component, the circuit is broken and they all stop working, unlike parallel
Current is the same everywhere
PARALLEL
current is shared between branches
Is a voltmeter used in parallel or series circuit
Connected in parallel with a component to measure the potential difference in volt across it
What is potential difference
Also known as voltage
Energy transferred per unit charge passed and hence that the volt is a joule per coloumb
What is the equation for energy transferred
E = QxV
energy transferred (J) = charge moved (coloumb,C) x potential difference (volt,V)
Is an ammeter series or parallel
Series with a component to measure current, in amps
What is the electric current
Rate of flow of charge and the current in metals is a flow of electrons
How to calculate charge
Q = I x T
charge (coloumb, C) = current (amps, A) x time
