The Circulatory System
Which main organ in the human body continuously pumps blood?
Heart
Which gas do humans absorb from the air when they breathe in?
Oxygen
What is the biological period of transitioning from childhood to adulthood called?
Puberty
What do we call organisms, like plants, that make their own food at the start of a food chain using sunlight?
Producers
Which man-made material pollutes nature, does not decompose, and harms marine food chains?
Plastics
What is the name of the blood vessels that carry blood away from the heart?
Arteries
Into which main organs does the air travel after passing the trachea?
Lungs
What often develops on the skin or face during puberty due to oily glands?
Acne or Pimples
What do we call organisms that cannot make their own food and must eat other living things?
Consumers
What do we call dangerous substances that can move through food chains and poison living organisms?
Toxins
What do we call the rate or count of heartbeat measured at the wrist or neck?
Pulse
What is the large muscle at the bottom of the chest cavity used for breathing?
Diaphragm
What is the monthly shedding of the uterine lining in females called?
Menstruation
What is a network of many interconnected, overlapping food chains called?
Food-web
What gets disrupted or broken in nature when a whole species completely disappears from a food web?
Balance
What special structures inside veins prevent blood from flowing backward?
Valves
What are the tiny air sacs inside the lungs where gas exchange takes place?
Alveoli
What is the male reproductive cell called?
Sperm
What flows or transfers from producers to consumers along a food chain?
Energy
At which position in the food chain (usually the apex predators) do harmful substances build up to their highest, most dangerous levels?
Predators
Which specific blood cells are responsible for fighting off infections and diseases?
White-blood-cells
Which waste gas do humans release from their bodies when they breathe out?
Carbon-dioxide
What are the chemical messengers inside the body that trigger puberty?
Hormones
What is the scientific term for animals that eat only plants (primary consumers)?
Herbivores
What is the specific chemical term for substances sprayed by humans to kill pests that accidentally poison entire food webs?
Pesticides