Puberty
the process through which our body changes and develops so that we are able reproduce
puberty
produces mucus
respiratory system
function of a heart
pumps blood around the body
Our body uses ............. to break down the food we eat and release energy.
oxygen
freezing and melting are ..................changes
reversible /physical
Puberty usually begins between ages ...
8 and 14
2 ways to avoid being bitten by mosquitoes
sleep under a mosquito net/ wear long sleeves and long pants/ use mosquito repellent
Arteries transport blood away from the heart.
Name two other types of blood vessels.
veins and capillaries
In which organ does gas exchange take place?
lungs
Why is boiling reversible?
the water vapour can cange back to water by condensation/ boiling can be reversed by condensation
2 changes that happen to males during puberty
voice deepen/ facial hair growth/shoulders broaden/more muscular body
An astronaut’s mass is 60 kg on Earth. What will happen to his mass and weight on the Moon?
mass -stays the same
weight -lesser/changes
nutrients/oxygen/waste/minerals/carbon dioxide/digested food/
What is the phase of the moon when it is found between the Sun and the Earth?
new moon
A chemical reaction has taken place. Write down one observation that support this statement.
bubblesorgas produced/colour change/new substance is made
2 changes that happen to females during puberty
menstruation starts/ hips widen/breasts grow bigger/body hair growth
Vectors are living things, such as mosquitoes that carry...
pathogens from one host to another
Our circulatory system is made up of...
heart, blood, and blood vessels
Function of the Respiratory System.
It brings ...........from the air to our ............... so that it can be transported around the body
oxygen...blood
The magnesium reacts with hot water. Hydrogen gas and magnesium hydroxide are made.
Name two reactants.
magnesium and water
What causes the sudden increase in growth in boys and girls?
puberty/hormones
small plants---> fish----> birds
A toxic chemical is sprayed on the water to kill mosquito eggs. Use the food chain to explain why toxic chemicals kill the birds.
The toxic chemical is ................... by the small plants then ................................
absorbed .... then the birds eat the fish that eats the small plants
function of the circulatory system
transports useful substances to all parts of the body
Trace the flow of air into our body.
Nose → Trachea (windpipe) → Bronchi → Bronchioles → Alveoli (air sacs in lungs) → Blood
The cooking gas used for camping is commonly made of butane gas. It burns in oxygen to give out heat. It also produces carbon dioxide and water vapour as it burns.
Identify 2 products.
carbon dioxide and water vapour