Science Semester 2 Exam - 2019

pathogen

An organism that causes disease

viruses

non-cellular, non-living, tiny, genetic material surrounded by a protein coat, harmful

diseases caused by viruses

common cold, influenza, hepatitis, cold sores, warts, chicken pox

Virus reproduction

Attach to host cell, make copies of themselves in the host cell, take over cell, cell breaks open (cell dies) and releases new viruses

virus treatment

can't be treated with antibiotics, can be treated with antiviral medication

bacteria

tiny, single-celled organisms, no nucleus, harmful and useful

cocci

spherical bacteria

bacilli

Rod shaped bacteria

spirilla

spiral shaped bacteria

diseases caused by bacteria

gonorrhea, syphilis, salmonella, staphylococcus, cholera

requirements for bacteria

warm, moist, supply of nutrients

culturing bacteria

agar

nutrient jelly, sourced from seaweed, used to grow microorganisms

Bacteria reproduction

binary fission

bacteria treatment

can be treated with antibiotics

useful bacteria

digestive system, yoghurt

quarintine

forced isolation to prevent the spread of disease

antiseptics

Substance that prevent the growth of bacteria on living tissue

disinfectants

substance that kills bacteria on non-living surfaces

antibiotics

substances that kills bacteria

vaccination

injection of a weakened or mild form of a pathogen to produce immunity

memory cells

lymphocyte capable of responding to a particular antigen on its reintroduction, long after the exposure that prompted its production

first line of defence

barriers

Examples of first line of defence

skin, eyelashes, tears, nose hairs, mucus, saliva

second line of defence

internal non specific defences

examples of second line of defence

phagocytes, white blood cells, eat up pathogens

inflammation

increases blood circulation around the infected area

third line of defence

internal specific defences

examples of third line of defence

lymphocytes and antibodies, which target specific pathogens

antigen

a toxin, parts of the pathogen, that induces an immune response

antibody

A protein that acts against a specific antigen

nervous system

the body's communication network, consisting of a network of nerve cells, that transmits nerve impulses throughout the body.

sensory neurons

carry information from the sensory receptors to the central nervous system

motor neurons

carry information from the central nervous system, to the muscles and glands, to produce movement.

Interneurons

neurons within the brain and spinal cord, communicate internally between the sensory inputs and motor outputs

cell body

the cell's life support centre, contains necessary components to keep cell alive

Dendrites

Branchlike parts of a neuron that, receive messages from other cells

axon

carries electrical messages from the dendrites to the axon terminal

axon terminal

The endpoint of a neuron where neurotransmitters are stored

myelin sheath

a fatty tissue layer, covering the axons of neurons, helps speed of messages

Synapse

Gap between neurons, where chemical information is transmitted from one neuron to the next.

reflex response

involuntary reaction to a stimulus

reflex response importance

very fast response, message doesn't initially travel to the brain, no conscious thought

reflex arc

sensory receptor, sensory neuron, spinal cord, motor neuron, effectors

voluntary nerve pathway

sensory receptors, sensory neurons, brain, motor neurons, effectors, movement

involuntary nerve pathway

sensory receptors, sensory neurons, central nervous system, pre and post ganglionic neurons, effectors, movement

endocrine system

chemical communication system, Consists of glands, that secrtes hormones into the bloodstream, to control many of the body's activities

hormones

Chemical messages, produced by your glands, that control many of our bodily functions

glands

a group of cells, that produces hormones, for release into the bloodstream

thyroid gland

produces thyroxin

thyroxin

regulates metabolism

adrenal gland

produces adrenaline

adrenaline

response to physical or mental stress, increases heart rate,

pituitary gland

master gland

testes

produces testosterone

testosterone

Male sex hormone

ovaries

produces oestrogen, and progesterone

pancreas

Regulates the level of sugar in the blood and produces insulin

Glucose regulation

The process of maintaining optimal blood glucose levels

insulin

regulates how the body uses and stores glucose and fat, lower blood sugar levels

Glucagon

raises blood glucose levels

diabetes

A condition in which the body is unable to produce enough insulin, and prevents the body from converting food into energy

Stimulus Response model

Stimulus, receptor, sensory neurons, central nervous system, motor neurons, effector, response

Homeostasis

the process of keeping the internal environment constant, despite the external environment.

Homeostasis example

Sweat when body overheats, shiver when it is cold

central nervous system

consists of the brain and spinal cord

disease

A condition which interferes which the normal functioning of an organism

effector

An organ or cell that acts in response to a stimulus

genetic engineering

The deliberate modification of the characteristics of an organism by manipulating its genetic material

immunity

Able to make the antibodies to a pathogen before it can make you unwell, resistance to disease

neuron

The basic unit of the nervous system

Neurotransmitters

chemical messengers that cross the synapse gaps between neurons, passing the information along

natural flora

Organisms that usually inhabit the human body and are non-pathogenic

parasite

An organism that lives on or in the body of the host gaining benefit from the host, and causing harm to the host

perhipheral nervous system

The nerves that carry messages to and from the CNS and other parts of the body

reflex

An action that occurs without conscious thought as a response to a stimulus, The message does not initially travel to the brain

stimuli

Something that causes a response

target cell

The cell on which a hormone acts

toxin

Poisonous waste produced by a pathogen

vector

An organism which transfers the pathogen from host to host

phagocytes

A type of white blood cell that engulfs pathogens and other particles

lymphocytes

A type of white blood cell that make antibodies to fight off infections

fossil

A trace of an ancient organism that has been preserved in rock.

unaltered fossil

fossils of the actual animal with relatively little change over time

average thickness of continental crust

40 km

average thickness of oceanic crust

8km

tectonic plates

Large movable plates under the Earth's surface.

crust

The layer of rock that forms Earth's outer surface.

Mantle

the layer of the earth between the crust and the core

outer core

the liquid layer of the Earth between the mantle and the inner core

inner core

a dense ball of solid metal at the centre of Earth

mantle thickness

2900 km

outer core thickness

2,200 km

inner core thickness

1200 km

Crust composition

Lighter rocks such as basalt and granite

outer core composition

liquid iron and nickel

inner core composition

solid iron and nickel

Lithosphere

A rigid layer made up of the upper part of the mantle and the crust

Asthenosphere

The soft layer of the mantle on which the tectonic plates move

continental crust density

less dense