Cells and Control Flashcards
What are the uses of stem cells?
To create new, healthy cells to replace faulty cells
What are the advantages of embryonic stem cells?
Easy to extract from embryo
Can produce any type of cell
What are the disadvantages of embryonic stem cells?
Embryo is destroyed when the cells are removed
What are the advantages of adult stem cells?
No embryo has to be destroyed so there is no ethical issue with using adult stem cells
The body won’t reject stem cells taken from itself
What are the disadvantages of adult stem cells?
They can only produce a few types of cell
What are the issues with all types of stem cells?
Stem cells may never stop dividing and cause cancer
What are the functions of the medulla oblongata?
Controls heart rate and breathing rate
What are the functions of the cerebral hemispheres?
Controls voluntary movement, interprets sensory information and is responsible for learning and memory
What are the functions of the of the cerebellum?
Co-ordinates and controls precise movement
When does mitosis happen?
When new diploid cells are needed for growth, repair and asexual reproduction
How does growth in animals happen?
Mitosis - more cells are created
Examples of specialised animal cells
Red blood cells
Nerve cells
Egg and sperm cells
How does growth in plants happen?
Cells enlarge and elongate
Examples of specialised plant cells
Xylem
Phloem
Root hair cells
What are the differences in cell differentiation in plants and animals?
Most plant cells can continue to differentiate throughout life whereas animal cells lose this ability at an early stage
What are the uses of percentile charts?
They’re used to determine if a child is growing faster or slower than normal for their age
What is growth?
Permanent increase in size
How do CT scans work?
- Patient given a radioactive tracer so different parts of the brain show up
- CT scan carried out where many different x-rays of the brain and skull are taken from different angles
- Computer puts all the images together to form a 3D image
How do PET scans work?
- Patient given small amount of radioactive form of glucose which travels to parts of the body where respiration is occurring rapidly
- Shows up in parts of the body which might indicate damage or disease
- Scanner detects radioactivity and builds up images of where the radioactive tracer is most concentrated
What are the side effects of treating brain tumours?
Removes brain tumour but also can cause damage to healthy nervous tissue
What is the spinal cord?
Made of nerves, protected by the spine
What are the functions of sensory neurones?
Carry impulses to the central nervous system
What are the functions of motor neurones?
Carry impulses from central nervous system to effector organs
What are the functions of relay neurones?
Carry impulses from one part of the central nervous system to another
What are the stages of mitosis?
IPMAT Interphase Prophase Metaphase Anaphase Telophase
What happens at each stage of mitosis?
Interphase- DNA is copied and chromosomes start to become visible
Prophase- Chromosomes are formed and each one consists of two chromatids
Metaphase- Nuclear membrane breaks down and chromosomes line up along middle of cell
Anaphase- Chromatids separate and one chromatid from each pair is pulled to either pole of the cell (the chromatids are now called chromosomes
Telophase- Spindle fibres disappear and a new nuclear membrane is formed round each group of chromosomes
Cytokinesis- The cell splits into two
What is a synapse?
The gap between two neurones
What does a neurotransmitter do
Carry impulses across a synapse
What do reflex arcs do?
Help prevent pain by providing a fast response that doesn’t involve the brain
What do pluripotent and totipotent mean?
Pluripotent- The stem cell can develop into a few types of cell
Totipotent- Can develop into all types of cell
What path does an impulse take to get to the effector organs the nervous system?
Receptor>sensory neurone>relay neuron>motor neuron>effector
What does the lens of the eye do?
Refracts the light and focuses the light to the back of the eye
What is the cornea?
Clear colourless covering which focuses and refracts the light - on the outside of the eye
What is the iris?
Ring of muscle that controls the size of the pupil
What is the conjunctiva?
A protective layer over the cornea
What is the name of the sperm head?
Acrosome
What is the name of the tail of a bacterial cell?
Flagellum
What is long-sight?
Where people can focus on distant objects but not near ones
How can long-sight be corrected?
Converging lenses
What is short-sight?
When people can focus on close objects but not distant ones
How can short sight be corrected?
Diverging lenses
What are cataracts?
A problem with the eye that occurs when the lens becomes cloudy, treated by replacing the lens with an artificial one
What is colour blindness?
The retina contains 3 types of cone, colour blindness occurs when there is at least one cone missing or that doesn’t work properly.
What is the purpose of the acrosome?
Contain enzymes to break through the egg cell membrane
How is a root hair cell adapted for it’s purpose?
Has a long thin finger like shape to increase surface area and allows water and minerals to absorb in quickly
How is a sperm cell adapted for it’s purpose?
The head contains genetic information and an enzyme to help penetrate the egg cell membrane. The middle section is packed with mitochondria for energy. The tail moves the sperm to the egg
How is a red blood cell adapted for it’s purpose?
Thin outer membrane to let oxygen diffuse through easily. Bi-concave shape increases the surface area to allow more oxygen to be absorbed efficiently. No nucleus, so the whole cell is full of haemoglobin which is used to carry oxygen.
Why are injuries in the spinal cord difficult to treat?
Because it’s protected by the spine it’s difficult to get to and the spinal cord is made up of specialised cells meaning the body will struggle to repair itself as it requires stem cells
What is special about palisade cells?
They have extra chlorophyll to help with photosynthesis
What is the vacuole?
A bag like structure which holds water and nutrients and helps keep the cell rigid
What is a chloroplast?
Organelle which contains green pigment call chlorophyll. Chlorophyll is used in photosynthesis
What do ciliated epithelial cells do
Keep the airways clean by trapping dust and microbes
What do arteries do?
Carry blood away from the heart
What does the cell membrane do?
Controls what goes in and out of the cell
How do we see?
- Light enters through your pupil
- The cornea and lens focus that light on the retina
- The retina contains special receptor cells called rods and cones that detect the light
- The rods and cones convert the light into electrical signals and sent to the brain along the optic nerve
What do mitrochondria do?
Carry out respiration in the cell
What does the cytoplasm do?
Provides cell shape and is where reactions take place
What are ribosomes?
Where protein synthesis happens, the process in which proteins are made
