Topic 2 - Cells and Control Flashcards
What do our chromosomes contain?
Our genetic information - what makes us like we are
What is the cell cycle?
Division of cells to produce new cells
What is interphase in the cell cycle?
- Amount of subcellular structures increases
- DNA is copied, forming X chromosomes, with the two halves being identical
What is mitosis?
The division of cells to form 2 identical daughter diploid cells
What are the 4 stages of mitosis?
Prophase - Chromosomes condense, nuclear membrane breaks
Metaphase - Chromosomes line up at the centre of the cell
Anaphase - Cell fibres pull chromosomes apart
Telophase - Membranes form around the sets of chromosomes
What is cytokinesis?
The cytoplasm and cell membranes divide into two separate cells
What is cancer?
The uncontrollable division of cells
What can percentile graphs be used for?
Monitoring growth - they show weight compared to age, and where your child fits on that graph
What are stem cells?
Undifferentiated cells that can become any specialised cell
Where are stem cells usually found?
In human embryos, as the cells have only divided, and have not yet become specific to one purpose
Where can stem cells be found in fully developed adults?
Bone marrow
What are stem cells mainly used for?
Medicine - Stem cells can become any type of cell, and so can fix diseases that are caused by poorly formed cells
What is the CNS?
Central Nervous System
What two components make up the CNS?
- Brain
- Spinal Cord
Name 3 parts of the brain, and their functions:
- Cerebrum: Divided into two hemispheres, right side controls muscles on the left side and vice versa. Different parts are responsible for different things such as movement, intelligence, memory, etc.
- Cerebellum: Muscle coordination
- Medulla oblongata: Control unconscious activities such as breathing and your heart rate
What are the two types of brain scans?
- CT Scan: Produces an image of the brain
- PET Scan: Uses radioactive materials to show what parts of the brain are active
What does the CNS coordinate?
Responses
What are three types of neurones?
- Sensory Neurone
- Motor Neurone
- Relay Neurone
How do neurones transmit information?
Through electrical impulses
What do synapses do?
Connect neurones
What is a reflex?
Automatic, rapid responses to stimuli
Where does information move to and from ina reflex?
From a receptor to an effector
What are the different parts of the eye, and what are their functions?
- Cornea: Refracts light into the eye
- Iris: Controls how much light enters the eye
- Lens: Focuses light onto the retina
- Retina: Detects light at the back of the eye
- Rods: Sensitive to dim light
- Cones: Sensitive to different colours
- Optic Nerve: Carries electrical impulses to the brain
What causes colour blindness?
Red or green cones that do not work properly
