Topic 2 - Cells and control

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oriane 🫧🎀🎧🧘🏻‍♀️

Cards (58)

What is differentiation?
Process of unspecialised cells undergoing changes to become specialised cells
What are stem cells?
Cells with potential to develop into specialised cells
What are adult stem cells?
Undifferentiated cells that can only develop into certain specialised cells
What are embryonic stem cells?
Undifferentiated cells which can become any type of specialised cell
Order of the nervous system?
Stimulus
Receptor
Sensory neurone
Relay neurone (CNS)
Motor neurone
Effector
Response
Sensory neurone purpose?
Nerve cells activated by sensory input from the environment
Relay neurone purpose?
Allows sensory + motor neurones to communicate
Motor neurone purpose?
Allows us to respond by sending signals from brain to muscles
What is a synapse?
A junction between neurones which allows for the transmission of neurotransmitters (electrical signals converted to chemical signals) through diffusion across the gap to the receptors of the next neurone so electrical signal can carry on flowing
Mylein sheath purpose?
Acts as an electrical insulator to allow electrical impulses to move faster
Axon purpose?
Sends electrical signals
What is in the cerebrum?
Right and left cerebral hemispheres
Right cerebral hemisphere function?
Controls muscles on the left of the body
Left cerebral hemisphere function?
Controls muscles on the right of the body
Medulla oblongata function?
Controls unconscious actions e.g breathing
Cerebellum function?
Muscle co-ordination, balance, posture
Limitations of CT scans?
Ionising radiation exposure could cause cancer
How do PET scans work?
Uses radioactive chemicals to show active parts of a brain
Limitations of PET scans?
Chemical imbalance in body could lead to incorrect results
How do CT scans work?
Patient lies on bed and passes through a ring that takes x-ray images from different angles
Pictures then processed by computer to see inside
Why can’t X-rays simply be used to see inside the brain?
They can’t penetrate through the skull
What is are dendrons?
Branches that receive incoming impulses from neurones
Benefits of using stem cells in medicine
Replace damaged cells
Grow organs for transplants
Downsides of using stem cells in medicine
Risk of rejection by the body’s immune system
Could turn into cancer cells
What is cancer a result of?
Uncontrolled cell division
What is mitosis?
The process of cell division in which a single cell divides into two identical daughter cells
What is the order of mitosis?
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
What is interphase?
The cell grows and prepares for division by duplicating its DNA
What is prophase?
Chromosomes condense and lie free in the cytoplasm
What is metaphase?
Chromosomes line up in the middle of the cell
What is anaphase?
Spindle fibres pull the chromosomes lined up in the middle of the cell apart
What is telophase?
Membranes form around each chromosome pair which the spindle fibres pulled apart
What is cytokinesis?
Two identical daughter cells (both diploid cells) are formed at the end of mitosis
What is a haploid cell?
A cell with a single set of chromosomes
What is a diploid cell?
A cell with two sets of chromosomes
How many chromosomes in a single set?
23
How does cell division occur?
Mitosis or meiosis
What is cell elongation?
Cell division which occurs in meristems of plants which causes them to grow
When does cell division stop in animals?
When they reach full growth -> cell division is then used mostly for repair
What are meristems?
Stem cells in plants that divide and differentiate into specialised tissues e.g xylem and phloem