Cells
What part of the cell controls the cell's activities and contains DNA?
Nucleus
What gas do humans breathe in that the body needs for energy?
Oxygen
how many chambers does the heart have?
four
What is the main job of the digestive system?
To break down food and absorb nutrients.
How many hearts does an octopus have?
three
Which structure controls what enters and leaves the cell?
Cell membrane
What gas do humans breathe out as waste?
Carbon dioxide
What substance in the blood carries oxygen to the body's cells?
Red blood cells / haemoglobin
Which organ absorbs most nutrients from food?
Small intestine
What is the largest organ in the human body?
skin
Which organelle allows plant cells to make food using sunlight?
Chloroplast
What muscle below the lungs helps you breathe by contracting and relaxing?
Diaphragm
Why does heart rate increase during exercise?
To deliver more oxygen and nutrients to muscles.
What tiny finger-like structures increase the surface area of the small intestine?
Villi
What is the smallest bone in the human body?
The stapes (ear bone)
Which structure stores water and helps maintain pressure in plant cells?
Vacuole
What happens to the lungs when the diaphragm contracts?
The lungs expand and air is drawn in
How do the respiratory and circulatory systems work together during exercise?
The respiratory system brings in oxygen and the circulatory system transports it through the blood to muscles.
Why is a large surface area important in the small intestine?
It allows more nutrients to be absorbed into the bloodstream.
What animal has the largest brain relative to its body size?
ant
Name two differences between plant and animal cells.
• Plant cells have cell walls
• Plant cells have chloroplasts
• Plant cells have large vacuoles
What would likely happen if the diaphragm stopped working?
You would not be able to breathe properly because the lungs could not expand.
Why does heart rate decrease during recovery after exercise?
The body needs less oxygen once muscles stop working as hard.
How could damage to villi affect the body?
Fewer nutrients are absorbed, which can affect growth and health.
Which animal can regenerate (regrow) an entire arm or leg if it loses one?
starfish