Science Exam

What does a cell needs to stay alive and why?

Energy - to do all functions

Nutrients - to repair and make

Oxygen - best for energy, making

Remove waste - waste is poison

Be at the right temp - correct function

Have enough water - correct function

What is the environment of an organism?

All the things that are around it can affect or influence it eg other animals plants and non living factors eg temperature

What are some examples of Responding to the Environment?

Kangaroo - Being an animal responds faster to environment - when hot Kangaroos seek shade to stay cool

Eucalyptus (Gum) Tree - As a plant cant respond as fast has fewer choices - Eucalyptus trees let their leaves hang vertically, so they can be side-on to the sun to stop from heating up.

Give another example of a Kangaroo and an Eucalyptus tree responding to the Environment

Kangaroos: They don't sweat, so they lick their forearms to cool off

Eucalyptus (Gum) Tree: They have pale leaves to reflect more of the hot sunlight

What is an Adaptation? Provide an example

Are changes that are 'built in' to the organism - it can happen over a long period of time through evolution - eg Kangaroo coast colour, large legs for travelling

What is an Response? Provide an example

A Response is where the organism can 'choose' to actively do it when their environment changes - e.g Kangaroo licking themselves to keep cool

What are some plants responding to the environment?

Some plants detect that they are being eaten and send out a poison or 'bittering' agent to deter predators

What are some Plants Responses?

Photo tropism (response to light)

Geotropism (gravity)

Chemotropism (particular substances)

Hydrotropism (water)

thigmotropism (mechanical stimulation)

What Makes up a Multicellular organism?

Cells - basic unit of life

Tissue - Cells that are similar come together

Organs - Tissue work together to form organs

Organ system - work together to do a function

Organism - All organ system work together to form complete organism

What are specialised cells?

They are cells that are involved in specific functions e.g pancreas insulin, to ensure homeostasis

What is the role of the nervous system?

A complex network of cells, tissues and organs that work together to coordinate (organise) an organism's response to the changing environment

What is the role of central nervous system?

The central nervous system responsibilities include receiving, processing, and responding to sensory information, it consists of the brain and spinal cord

What is the role of the Peripheral Nervous System?

The Peripheral nervous system is a network of nerves outside the brain and spinal cord that connects to the CNS and the rest of the body. It transmits sensory information to the CNS, carries out motor commands and regulates involuntary functions such as heartbeat and digestion

What are sensory organs give examples.

Sensory organs are responsible for collecting information from environment, they send signals to the nervous system. Sensory organs include eyes, ears, nose, tongue, and skin

What are neurons?

Neurons (nerve cells) act like wires throughout the body. Each neuron communicates with and/or with the rest of the body. They carry signals called nerve impulses

What are the three main types of neurons?

Sensory neurons transmit information from sensory receptors in the body such as eyes or ear to the central nervous system.

Motor Neurons transmit information from the central nervous system to muscle or glans, allowing us to control out movements and bodily functions

Interneurons: These neurons are responsible for transmitting information between other neuron in the Central Nervous System

What is the Endocrine System?

The Endocrine system is the slower communication system. It sends message around an organism by releasing chemical called hormones from glans, which tells the cell what to do. Blood in animals, Sap in plants.

What are hormones?

They are chemical messengers that coordinate different functions in your body, secreted by endocrine glands

What are Glands and give examples

Endocrine glands are glands that release hormones directly into the blood stream. Examples include:

Pituitary gland

Hypothalamus

Thyroid gland

Adrenal glands

Pancreas

Gonads

What is the role of Testosterone, Adrenaline, Insulin

Testosterone - makes males a male. Growing body hair, increase muscles, even causes aggression

Adrenaline: When you are scared, makes heart beat faster, tense muscles, focused mind

Insulin - Responsible for controlling level of glucose (sugar) in your blood. Glucose is energy that cells need to stay alive

What is the role of insulin?

Tells body when to release stored energy (from food or fat) when you start to run low. Or when you have to much so it can store for later - too much = poison

What does the peripheral nervous system consist of?

Nerves and ganglia (cluster of nerve cell bodies)

What is the peripheral nervous system divided into?

Somatic (voluntary movement such as walking or speaking) and Automatic (controls involuntary movements such as heart rate and breathing)

What is the autonomic nervous system divided into?

Sympathetic (prepares for stressful) and Parasympathetic (promotes relaxation and rest)

What are Tropisms?

Directional growth responses of plants to environmental stimuli such as light.

When a plant detects environmental stimuli what hormone does it produce?

Auxin

How does auxin play a role in phototropism?

It produces more auxin on the side of the plant that is farthest from the light source -> results in plant bending towards light

How long can hormones stick around for?

Hormones can last minutes, some last months

What can/do hormones affect?

Hormones can affect the whole body or it can be designed to only affect particular parts

What is the form of information used to send messages in the Nervous and Endocrine System?

Electrical impulses (nerve 'impulses) - Nervous

Chemical signals - Endocrine

What is the pathway for information in the Nervous and Endocrine System?

Neurons (nerve cells) through out the body - Nervous

The circulatory system (bloodstream) - Endocrine

Where is the message sent from (source) in the Nervous and Endocrine System?

From Brain and Spinal Cord - Nervous

Various Glands through out the body - Endocrine

What is the Message duration of the Nervous and Endocrine System?

Short (instant) repeated if needed - Nervous

Long (Minutes, hours, or days) continually - Endocrine

What is the Message Target of the Nervous and Endocrine System?

One specific part (usually a muscle) to perform one task eg move arm - Nervous

Wide area- message goes everywhere (most part ignore it) - and can send different message - Endocrine

Provide some examples of the Body Systems Interactions

Your brain and nervous system see the predators, and send repeated messages to your muscles to start moving, and to your adrenal glands. -> your digestive system releases glucose, transported by circulatory system to the leg for energy

What is a disease?

A disease is any condition that prevents or stops the body from working well

What are some examples of diseases?

Influenza (flu)

Chickenpox

Depression

Covid-19

Food poisoning

What are infectious diseases? Give examples

Infectious diseases are something that you can catch/transfer to you when someone else has it

Influenza (The Flu)

Chickenpox

Covid-19

What are non-infectious diseases? Give examples

Non-Infectious diseases are something that you cannot contract if someone else has it

Food poisoning

Depression

Asthma

What are pathogens?

Single-celled microbes that cause disease

What are some examples of pathogens?

Bacteria, Fungi, Protists, Protozoa, Viruses, Parasites

What does the First Line of Defence do?

Keeps the pathogen out of our body, by blo9cking it or killing it on the way in

What does the Second Line of Defence do?

Killing the pathogen once it's inside the body, using 'general' attacks that affect most pathogens

What does the Third Line of Defence do?

Specifically targeted attack against particular diseases.

What are some Physical barriers in the First Line of Defence

Skin - Barriers to microbes

- Protects internal organs from e.g sun radiation

Nasal hair and sticky mucus lining in windpipe

- Acts as Air filter

- Coughing shifts clogged mucus

What are some Chemical barriers in the First First Line of Defence?

Saliva and tears - Has antibacterial enzymes that cleanse and flush particles

Stomach Acids - Kills most microbes before reaching the small intestines

Acid Mucus in Vagina - Chemical environment difficult for microbes to grow and multiply

What are Defences in the Second First Line of Defence?

Inflammation - Swelling and in affected area and redness caused by blood flow - more blood flow brings more red and white blood cells

Fever - Can slow down and cook some pathogens

White blood cells (phagocytes) surround and kill pathogens (called phagocytosis)

Lymphatic System - Removes foreign material and dead cells before it reaches the bloodstream

What are Resident Effector Cells?

Immune cells such as macrophages that stay in tissues to detect pathogens using special receptors

What are Patten Recognition Receptors (PRRs)?

Proteins on immune cells that recognise molecular patterns of pathogens to start immune response

What are Cytokines?

Small proteins sent out by immune cells to start inflammation and bring more immune cells in

What is vasodialation?

Where blood vessels get wider allowing more blood flow to infected area

What are Chemotaxis?

Movement of immune cells towards infected site by following chemical signals

What are neutrophils?

Fast-acting white blood cells that arrive first to eat bacteria and release germ-killing chemicals

What are Lymphocytes?

White blood cells that control specific immune responses. They learn what the disease is like. They trigger more lymphocytes to usea very particular attack against a specific pathogen. They also remember the pathogen for next time it enter the body

What are macropahges?

Large immune cells that stay in the tissue, detect pathogens, engulf (phagocytose) them, and release cytokines to alert other i mmune cells

What are B-Cells?

A white blood cells that makes infection-fighting proteins called antibodies

What are Memory B-Cells?

Are cells that continue to stay in your body and do not secret antibodies, until a second entry. It remembers the antigen for future re-entries.

What are are Antigens?

Antigens are a substance that trigger the immune response

What are T-Cells?

They are type of white blood cell (lymphocyte) that actively participates and controls your immune response.

What is a Cytotoxic T cell?

A cell that kills cells infected with the virus and bacteria

What are Helper T-Cells?

White blood cells that send signals to other cells in the immune system to coordinate an attack against pathogens

What is a vaccine?

An injection that contains a weakened or dead version of a pathogen that stimulates the production of antibodies.

How do vaccines work?

Vaccines insert a weakened or dead version of a pathogen which imitates an infection that engages your immune system to create antigens against the pathogen. Then memory cells remember this pathogen for the future

What is an inactivated vaccine?

It's a vaccine with a killed version of a germ, usually it doesn't provide long lasting immunity you need booster shots

What is a live-attenuated vaccine?

Is an alive, weakened version that causes an immune response similar to that of a natural infection without the serious illness, that can give long lasting protection

What is Herd Immunity?

When majority of a population are vaccinated against a disease, and are immune to it which limits the spread of the disease

How does Herd Immunity protect people who can get vaccinated?

As most people in a population is vaccinated it makes it hard for the disease to find people to spread to lowering the risk of exposure to non-vaccinated people

What is Quarantine?

Enforced isolation of people or animals that may have been exposed to an infectious disease

What is Immunisation?

To make somebody resistant to a disease, especially by vaccination

What is Coordination?

The ability to control different parts of the body at the same time in a smooth and efficient way, so they work well together

What is energy?

The ability to do work or cause change

What is energy measured in?

Joules (j)

What is electricity?

Electricity is the is a form of energy that involves the movement of negatively charged electrons in a conductor. The flow of electricity is called an electric current. Electricity flows from the negative terminal (-) positive terminal (+) of the cell

What is the structure of an atom?

All mater is made up of atoms which contains protons, neutrons, and electrons

When an object has equal number of protons and electron, the object has no charge

What are conductors?

Conductors are substances that allow electricity to pass through them. For example metals, such as copper or iron are good conductors for electricity

What are insulators?

Material that do not conduct electricity and can prevent people from getting electric shocks. E.g. Plastic, glass, and rubber

What is an electrical circuit?

An electrical circuit refer to the path taken by electrons in a conductors. Electrical circuit are made up of component that are joined together without any gaps to form a closed circuit

Where does Electricity come from?

Power Stations

Electric Cells (batteries)

What are the 4 essential items in a circuit?

An energy source, such as a cell or battery

A energy user or load (or loads) in which electrical energy is converted into other useful forms of energy (e.g light globe)

A conducting pathway (electrical wires) for the electricity to flow through

A switch to turn the current on and off

Will a light bulb light if it is an open circuit?

No, as the current of the electrons cannot flow

What is the meaning of current? The abbreviation for current? The unit for current? And the Measuring device for current?

Is the rate at which electrical charges (electrons) flow in a complete or closed circuit

The abbreviation for current is (I)

The unit for current is ampere (amps) (a)

What measures amps? Ammeter

What is the meaning of Voltage? The abbreviation for voltage? The unit for Voltage? And the Measuring device for voltage?

Voltage is the amount of electrical energy needed to move electrons around a circuit. It is the size of the push.

The abbreviation and unit is Volts (V)

What measures Volts? Voltmeter

What is the meaning of Resistance? The abbreviation for resistance? The unit for resistance? And the measuring device for resistance?

Resistance is the measure of how much a load (e.g a light bulb) restricts and/or reduces the flow of current - the opposition to the flow of current

Resistance if given the symbol R

The unit for resistance if ohm

Do you connect an ammeter in series or parallel?

Series

Do you connect a voltmeter in series or parallel?

Parallel

When connecting a meter, what side does the positive end of the meter go to?

It connects to the positive side of the terminal (battery)

What does a voltmeter measure?

The loss of energy e.g when electricity goes through something such as a lightbulb it compares the starting energy and the finishing energy

What is potential difference?

How much work can be potentially done by a circuit e.g a 9V battery the potential difference is 9V

Is the potential to do work, for e.g there is a 9V battery there is a potential to do 9V of work

Potential difference is the amount of energy an electron loses or gains in a circuit

What is a resistor?

Any conductor/component that opposes the flow of electricity

What causes greater resistance ?

Type of material e.g non metal high resistance

Length or wire - doubling length = more obstacles for electrons

Thickness of wire - More difficult for electrons to pass along thin wires

What is the effect of resistance on current and voltage?

Increasing the resistance will cause decrease in current and results in more energy being used up by the load (light bulb) producing heat or light

That is why Nichrome wires have more resistance than copper wires and are used in appliances which require heat or light

What is the Ohm's Law?

Is the relationship between Voltage, Resistance and Current

Voltage (V) = Current (I) x Resistance (R)

Current is directly proportional to Voltage and inversely proportionate to Resistance I= V/R. This means that higher voltage will result in higher current if resistance remain constant, and higher resistance will lead to lower current for a given voltage

Make an analogy of electricity as a water pump

Water pump (voltage

Water flow (current)

Water wheel (resistance)

Tap (switch)

Pipe (connecting wire)

What is a series circuit?

All in a row

A circuit that only has 1 path of electricity

1 light goes out and the circuit is broken

What is a parallel circuit?

Circuit that has more than one path for electrical current to flow through

1 light goes out and the other stay on

What happens to voltage in a series circuit?

All globes have the same current flowing through them but the supply voltage is shared between the components making all globes dimmer

Advantages and Disadvantages of series circuit?

Usually less components

Easiest of all circuit to connect up

Globes can not be controlled individually with a switch - all on or off

Current stops if one globe fails

More globes equals less brightness - ass supply voltage is shared amongst all

What happens if you add more light bulbs in a series circuit? Give an example of 3 light bulbs in a 9V circuit with 10 ohms of resistance each

The current in the circuit will go down (light bulbs dim) current = 0.3 amps

What happens to the voltage in a parallel circuit?

It stay the same across all components because each branch is connected to the power source directly

What are some advantages and disadvantages of parallel circuits?

Each branch has its own switch. This allows each globe to be turned on and off individually/independently -> only one branch is affected if one globe blows

Adding extra globes does not affect their brightness - each branch receives the same voltage

Disadvantages: more wiring

A short circuit (when someone jams a wire between two contacts of an electrical outlet) has very low resistance, which causes current to increase—bang!