Literally everything we covered in Y9 science 2025 (not including light, as it won't be on the test)

What is respiration

Respiration is the process of getting energy from out food, which is stored as chemical potential energy. This occurs in the mitochondria of every cell in our body

Aerobic respiration equation

Aerobic respiration is respiration that produces a lot of energy and is respiration with oxygen

Glucose + Oxygen ------> Carbon dioxide + Water + Energy (ATP)

anaerobic respiration equation

respiration without oxygen, incomplete breakdown of glucose. Produces less energy

Glucose ---> lactic acid + energy

difference between aerobic and anaerobic respiration

Aerobic respiration is respiration with oxygen and produces more energy. Anaerobic respiration is respiration without oxygen and produces lactic acid as a waste product.

What is breathing

movement of air into/out of the lungs.

requires the chest/muscles and diaphragm to draw air and push out air.

breathe in oxygen (for respiration), breathe out carbon dioxide (waste product)

list the path that air takes from the nose to the lungs for the gas exchange?

nose, trachea, bronchi (bronchus), bronchiole, alveoli

what is gaseous exchange?

happens in your alveoli

this is where oxygen is taken into the blood to be transported into body cells

at the same time, carbon dioxide is removed from blood into the alveoli to be breathed out.

BIG YAP ABT GASEOUS EXCHANGE - discuss how gaseous exchange occurs in the alveoli.

(btw its an excellence question)

When you breathe in, oxygen travels down your trachea and into your lungs. Inside the lungs there are tiny air sacks called ALVEOLI. Surrounding each air sack are small tubes that bring and carry away blood. They are called CAPILLARIES. When we breathe in, fresh air is drawn into the air sacks. Oxygen from the air passes into the blood, through the alveoli. At the same time, carbon dioxide passes from the blood into the alveolus. When we breathe out, carbon dioxide passes out of our bodies. This exchange of gases is called gaseous exchange. The blood carries oxygen to the cells from the lungs and carbon dioxide back to the lungs from the cells.

describe the process of breathing IN

1. the intercoastal muscles contract, these pull the rib cage upwards. The chest increases in volume.

2. The diaphragm contracts. This makes it flatten out so the chest gets even larger.

3. As the chest gets larger, air is sucked down the trachea and into the lungs.

describe the process of breathing OUT

1. Intercoastal muscles relax, rib cage lowers, chest decreases in volume

2. Diaphragm relaxes and bulges upwards. Volume of chest decreases.

3. Air is forced out of the lungs as chest becomes smaller.

What is metabolism

sum of all chemical reactions in the body, converting food and drink into energy for life functions

what is metabolic rate

refers to the rate at which the body uses energy

factors that affect metabolic rate

- age (younger people have higher metabolism compared to older people as they are more active)

- gender (males have higher metabolism compared to females as they have higher muscular mass)

- hormones (people who have high thyroid levels have high metabolic rates)

- activity (physical activity and exercise increase the metabolic rate because the body needs more energy).

Excellence question: why does a person's heart rate increase when a person exercises?

(FULL ANSWER FOR EXCELLENCE MARK)

When we are exercising, our body requires more energy, which comes from glucose through the process of respiration. Respiration is defined as getting energy through our food, with aerobic and anaerobic respiration being the two types. In aerobic respiration, it requires glucose and oxygen, producing carbon dioxide. C02 and O2 will then travel through the blood, making the heart work harder and pump faster due to the increased levels of gaseous exchange.

Heart rate increases because we need more energy, therefore, the heart will work harder for a higher respiration rate.

Unrelated excellence question: Discuss how vaccination helps in preventing some diseases.

Again, the full answer will give you the excellence mark (copied straight from my test paper)

A vaccine contains a weakened version of the pathogen and when it enters your body, your body will identify the pathogen through the antigens on the outer layer of the pathogen. The antigen basically causes the immune system to send a response so that it starts producing antibodies which latch onto the antigens and mark the pathogen for killing. The body also produces memory cells that remember the pathogen, helping the immune system work faster if the same pathogen ever re-enters the body, working fast enough so it doesn't cause illness. The remaining antibodies stay in the body just in case this pathogen ever returns.

define a balanced diet

A balanced diet contains adequate amounts of all the necessary nutrients from each food group required for healthy growth and activity.

why is a balanced diet important

It provides your body with the essential nutrients to function correctly and can help prevent diseases like heart disease, stroke, type 2 diabetes and some cancers.

5 main food groups and their functions

5 main food groups:

Carbs: for energy (bread, rice)

Fats: energy (oil, sugar, sweets)

Protein: growth and repair (meat, egg)

Fruits and Veg: vitamins and minerals for health bodily functions (APPLES)

Dietary fibre: helps in indigestion (green leafy veg)

7 main food groups

Carbs, fats, protein, vitamins, minerals, fibre, water

what are unsaturated fats

Unsaturated fats have at least one unsaturated bond in a place where hydrogen can be added to the molecule. They are usually liquids at room temp. (oil)

what are saturated fats

Saturated fats have all single bonds between carbon atoms and are usually solid and room temp. Too much saturated fats in your diet may lead to heart disease. (butter)

what are trans fats

Trans fats are fats that are artificially made by manufacturers. They add hydrogen to the fat molecules in vegetable oils. Typically found in chips and commercially baked baking.

what is digestion?

digestion is the process of breaking down food and absorbing its nutrients

Describe the entire process of digestion (emphasis on entire)

food goes into the mouth and gets broken down into smaller pieces by the teeth, saliva breaks the starch into glucose.

the small pieces of food then travel down the oesophagus and into the stomach via peristalsis.

stomach breaks down food into smaller pieces and protein into amino acids.

food then travels to the small intestine which contains villi, increasing the surface area. this helps food be absorbed into the bloodstream.

then travels down to the large intestine, water is absorbed.

feces goes to the rectum, where it is stored and out through the anus.

mouth

to take food into the digestive system.

chemical and mechanical digestion

teeth

tear, cut, grind food in mouth.

mechanical digestion

tongue

to move around food in the mouth and swallow

salivary glands

produces saliva that moistens food and helps to swallow.

oesophagus

transports food from the mouth to the stomach through peristalsis

stomach

to hold food and break down food with acids and enzymes. breaks down proteins into amino acids

liver

to process nutrients and produce bile, breaking down fat

gall bladder

to store bile from the liver and release it into the small intestine.

pancreas

produces digestive enzymes and releases into duodenum

also produces insulin

duodenum

breaks down food further using enzymes and bile (part of the small intestine)

small intestine

breaks down food from the stomach, absorbs nutrients and releases into body

large intestine

absorbs water from digested food to form feces

rectum

stores feces

anus

releases feces from body.

Distinguish between mechanical and chemical (enzyme) digestion

Physical digestion is the mechanical breakdown of food into smaller pieces like chewing. Physical digestion doesn't have any chemical reactions like chemical digestion. Chemical digestion is defined as the process where enzymes and acids break the chemical bonds in food molecules so the body can absorb them.

what is diabetes

Diabetes is when the body cannot properly use insulin for energy. It is caused by the insufficient or non-production of insulin by the pancreas.

difference between type one and type 2 diabetes

Type one diabetes is when your body does not produce enough insulin to convert the excess glucose into glycogen.

Type two diabetes is when your body does not respond to the insulin produced.

What is type 1 diabetes? (desc, cause, symptoms, how can it be managed)

Body's immune system mistakenly attacks and destroys insulin producing cells

Genetics, deficiency in insulin, low blood sugar

Urination, hunger, dizziness, delayed healing, blurry vision

Insulin therapy, healthy eating, managing blood sugar levels, physical activity.

What is type 2 diabetes? (desc, cause, symptoms, how can it be managed)

When your body cannot use insulin or produce enough insulin

Something you develop due to either genetics, weight, or lack of physical activity.

Thirst, tingling, hunger, dark areas, fatigue, blurred vision, numbness

Healthy eating, losing weight, medication

(can be rendered into remission via weight loss)

Explain the role of insulin in maintaining blood sugar levels

Compare how insulin works in a healthy individual

Insulin is a hormone produced by the pancreas that converts excess glucose into glycogen (energy). Insulin helps manage your blood sugar levels as it keeps it from going to high, which turns it into diabetes. In the management of diabetes, the role of insulin is to help reduce blood sugar levels. In type one diabetes this may mean insulin therapy and for type two it means lifestyle changes like weight loss and exercise (as they have insulin resistance).

how can diabetes be prevented?

You can't exactly prevent type 1 diabetes as it's genetic based but you can prevent type 2 diabetes through healthy eating, managing your weight and physical activity. Having a high fiber, low sugar diet can also be an effective way to prevent diabetes

List the four pillars of hauora

Taha tinana, taha hinengaro, taha wairua, taha whanau

Define taha tinana

Physical wellbeing:

Taking care of your physical health

Being organised

Taking breaks

Eating

Sleeping

Being physically active

Taha Wairua

Spiritual Wellbeing:

Striving for balance

Identity and values

Purpose and meaning

Can involve religions and praying

Taha Whanau

Social Wellbeing:

Being social with family and friends

Connecting with others

Asking for help

Define Taha Hinengaro

Physical and Mental Wellbeing:

Being aware of your emotions and reactions

Express feelings in appropriate ways

Think before you act

Managing stress

Describe and explain the factors that contribute to healthy living (diet, exercise, smoking, alcohol, drugs, lifestyle)

Healthy living is about making choices or habits supporting both physical and mental wellbeing. It is about taking care of your body- making sure you get enough sleep, eating and exercise.

Define and Calculate BMI

BMI = Body mass index

Weight (kg) / Height^2 (m)

Explain why BMI is not always a good indicator for healthy weight

BMI doesn't account for muscle mass so it may misclassify muscular people as overweight. It also doesn't consider age, sex or ethnicity.

Define a system [levels of organisation]

A system can be defined as a collection of interacting parrts working together to produce a unified whole.

When cells act together to carry the same function it creates tissue.

When tissue acts together it creates an organ.

When organs act together it becomes an organ system.

When organ systems work together it is an organism.

List all the human body systems

Endocrine system

Nervous system

Digestive system

Circulatory system

Reproductive system

Respiratory system

Muscle system

Immune system

Skeletal system

Integumentary system

Excretory system

Endocrine system

Maintains homeostasis, regulated metabolism, water and mineral balance, growth sexual development, reproduction

Nervous system

Controls and coordinates body movements and senses

Digestive system

Stores and digests food ---> absorbs nutrients, eliminates waste

Circulatory system

Transports nutrients and waste to and from all body tissues.

Reproductive system

produce offspring

respiratory system

Carries oxygen and carbon dioxide in and out of the lungs

Muscle system

Provides structure, controls movement, posture and assists with heat generation

Immune system

Provides protection against infectious diseases

Skeletal system

Provides structure, supports and protects internal organs

integumentary system

Protective covering of the body, provides UV protection, temp regulation

excretory system

Eliminates waste, maintains water and chemical balance

What are cells

Cells are the basic functional units of life

What are the two types of cells

animal and plant cells

Nucleus

holds dna

cell membrane

controls what goes in and out of cell

cell wall

provides support and structure (only found in plant cells)

Mitochondria

powerhouse of the cell. Makes energy

chloroplast

carries out photosynthesis. Makes glucose (sugar), only found in plant cells

vacuole

storage space, only found in plant cells

Cytoplasm

where chemical reactions take place, jelly like fluid

what are uncellular organisms?

uncellular organisms are one type of cell that carries out all the functions.

e.g amoeba, bacteria. pararnecium

multicellular organisms

use many cells to function,

e.g, humans, trees, bacteria

Define a physical quantiy

A physical quantity is something you can objectively measure using an instrument to give a value in standard units.

define length, distance, mass and time

Length: Shortest distance between two points (Units: mm, cm, m, km)

Mass: The amount of matter in a substance

Matter: Anything with mass / Anything that takes up space

Time: The duration of an event

What is parallax error and how to avoid it?

Measure from zero mark

• Parallax error - Always read at eye level at the bottom of the meniscus

• Repeat and average measurements to avoid random errors

Parallax error is a form of error that occurs when the position of the observer's eye is not aligned with the scale of the measuring instrument causing the value to be higher or lower than the actual value.

What do the sl prefixes mean for milli, centi and kilo

Milli = 1 thousandth

Centi= 1 hundredth

Kilo= thousand

What are conversion factors

Conversion factors are factors that change a measurement from one unit to another.

Define speed

Speed is the rate at which an object is changing with time

Speed formula

v=d/t

define the 3 variables in an experiment

Independent= What you change

Dependent= what you measure

Controlled= things you keep the same

Define forces

A force is a push or pull on a mass that can change an object's motion.

Forces push, pull, tug, heave, squeeze, twist or press.

Forces can change: the shape of an object, movement of an object, speed of an object, direction of object.

Not all forces can be seen but effects can be measured.

Unit: Newtons (N)

What are contact forces

Force where it needs to be in contact with the object experiencing it

Push or pull

Friction

What are non contact forces

Force that acts on an object from a distance without touching it

Gravity

Electrostatic

Magnetic

4 forces acting on a moving object

Weight/gravity, support, thrust, friction

Define friction

Friction is the resistance that one surface or object encounters when moving against another.

Explain the 4 forces

Friction is a force that is opposite to the applied force.

Thrust is an applied force.

Support forces are always equal and opposite to the gravitational force.

Gravitational force is experienced due to the pull from Earth

What are balanced forces

Balanced Forces= If pairs of forces are acting on an object are equal and opposite they are said to be balanced. The object would be stationary if all forces are balanced.

You can also say that when forces are balanced the object is moving at a constant speed in the same direction.

When forces are unbalanced there is a change in motion. They can change speed or direction on the object.

Change in speed= acceleration, deceleration.

Newtons 2nd law

Newtons 2nd law= If unbalanced forces act on an object, then object will accelerate in the direction that the net force acts. More than one force can act on one object in the same directory so forces are added.

Energy definition

Energy is the capacity for doing work

Two types of energy

Energy can be stored in different ways

Two kinds of energy: Potential energy (stored energy) and kinetic energy (energy due to motion)

energy is measured in

Joules (J)

List all the types of kinetic energy

Light (radiant energy)

Sound Energy

Mechanical kinetic energy

Heat/thermal energy

Electrical Energy

List all types of potential energy

Gravitational Energy

Elastic Energy

Nuclear Energy

Chemical energy

Geothermal Energy

Magnetic Energy

Explain the energy transformation occuring as a car rolls down a slope, before coming to a stop

As the car moves down the slope, gravitational potential energy is turned into kinetic energy and heat energy due to the friction. When the car has moved to the bottom of the slope, all gravitational potential energy is turned into kinetic energy. As the car is moving along the horizontal surface, kinetic energy is turning into heat energy. When the car comes to a stop, all kinetic energy is turned into heat energy.

define light energy

Energy traveling in waves, with wavelengths that can be seen by humans.