Biology Paper 2 (Content) Flashcards
What is CNS?
- Stands for Central Nervous System
- Brain and Spinal chord
What is type 1 diabetes?
- A disorder where the pancreas fails to produce enough insulin. People with type 1 diabetes have uncontrolled high blood glucose levels
What is type 2 diabetes?
In Type 2 diabetes the body cells no longer respond to insulin produced by the pancreas. Obesity is a risk factor for Type 2 diabetes.
How is Type 1 diabetes treated?
Insulin injections
What is the treatment for Type 2 diabetes?
A carbohydrate controlled diet and an exercise routine are common treatments.
What is DNA?
DNA is a polymer made up of two strands forming a double helix.
What is a gene?
A gene is a small section of DNA on a chromosome. Each gene codes for a particular sequence of amino acids, to make a specific protein.
What are the four bases of DNA?
DNA contains four bases, A, C, G and T
What is the DNA polymer made up of?
The DNA polymer is made up of repeating nucleotide units.
What is PNS?
- Stands for Peripheral nervous system
- All of the nerves in the body
Which one is CNS and which one is PNS?
- Left = CNS
- Right = PNS
What is the pathway through the nervous system?
Stimulus → Receptor → Coordinator → Effector → Response
What is a nerve?
A bundle of neurones
What is a reflex action?
- An involuntary (or reflex) action which does not involve the conscious part of the brain as the coordinator of the reaction
- Actions are automatic and rapid
What are the three types of neurones in a reflex action
- Sensory neurone
- Motor neurone
- Relay neurone
What type of neurone is this?
Sensory Neurone
What type of neurone is this?
Relay Neurone
Motor Neurone
What is a synapse?
The junction (gap) that separates neurones
What is the cerebral cortex?
The outer layer of the brain responsible for consciousness, intelligence, memory and personality
What is the cerebellum?
Underneath the cerebral cortex in the brain and is responsible for balance, muscle coordination and movement
What is the medulla?
The medulla in the brain controls unconscious activities such as heart rate and breathing
Label the brain
A = Cerebellum
B = Medulla
C = Pituitary Gland
D = Cerebral Cortex
What is homeostasis?
- Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
- Homeostasis maintains optimal conditions for enzyme action and all cell functions
- (Examples) In the human body: Blood glucose concentration, Body temperature and Water levels
What is the function of the cornea? (Function = what does it do?)
Transparent (clear) lens that refracts (bends) light as it enters the eye
What is the function of the iris? (Function = what does it do?)
Controls how much light enters the pupil
What is the function of the lens? (Function = what does it do?)
Transparent disc that can change shape to focus light onto the retina
What is the function of the retina? (Function = what does it do?)
Contains light receptor cells - rods (detect light intensity) and cones (detect colour)
What is the function of the optic nerve? (Function = what does it do?)
Carries sensory nerve impulses between the eye and the brain