Topic 2 Biology Flashcards
What are the 6 stages in mitosis
Prometaphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
What is mitosis for
Growth and development or replacing damaged cells
What are embryonic stem cells are what are their uses
Embryonic stem cells are undifferentiated and therefore can be specialised into anything
Like repairing diseased tissue and organs
Ehat are adult stem cells and their uses
Adult stem cells are more differentiated than embryonic stem cells and can be used to make different blood cells
Plant stem cells characteristics
Xan differentiate to form any type of plant cell
Present throughout entire plant lifespan
What are the benefits of stem cell research
They can be used to replace diseased or damaged body parts
Unwanted embryos from fertility clinics can be used
Research the process od differentiation
What are rhe disadvantages of stem cell research( part 1)
Removal of stem cells result in the destruction of the embryo
Religious or ethical issues
If the stem cells have a virus its transferred to the individual
Money and time could be spent on more important areas of medicine
What are examples of reflex arcs
Pupils getting smaller to avoid damage from bright lights
Moving hand away from hot surfaces
What happens in ct scans
They fire radiation at the brain which reflects and creates a 3d image - not suitable for pregnant women are children
What happens in pet scans
A radioactive tracer is put into the blood before scan - areas with high blood flow show up - cancerous tumors take up more blood flow
How does a reflexes work
When the impulse reaches the end of the first neuron a chemical called a neurotransmitter is released into the synapse
Rhe neurotransmitter diffuses across the synapse
When the neurotransmitter reaches the second neuron it triggers rhe impulse to continue in the second neuron
What is the retina and ehat does it do
Layer of light sensitive cells - light hits the cells - cells are stimulated - impulses sent to brain which interprets image
Made up of cones and rods
Rods = good for low light
Cones = good for colours
What is the cornea and what does it do
See through layer at front of eye
Allows light through and the curved surface is bended to focus light onto retina
What is the iris and what does it do
The iris is cells which contract or relax to light more or less light in by altering size of pupil
Bright light - iris contracts to let see through pupil - reduce damage to retina
Low light - relaxe to let more light through to let more light hit retina
What do ciliary muscles and suspensory ligaments do
Hold lens in place and change its shape to allow us to focus on far away and nearby objects
