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Showing 3 questions in Biology for Class 10. Tap a card to reveal the answer.
BiologyLife ProcesseseasyHow is oxygen transported from the lungs to the tissues in human beings?
Reveal answer ↓
What it is
Oxygen rides on haemoglobin in red blood cells from the lungs to every tissue.
Answer
Oxygen diffuses from the air sacs (alveoli) of the lungs into the blood, where it binds to the red pigment haemoglobin in red blood cells to form oxyhaemoglobin. The blood carries it to the tissues, where oxygen is released for respiration. Haemoglobin makes this transport efficient because it has a high affinity for oxygen.
- •O2 diffuses from alveoli into blood
- •Binds to haemoglobin in RBCs
- •Carried as oxyhaemoglobin
- •Released at tissues for respiration
Why learn this
It's why anaemia leaves you tired and why blood is red - the body's oxygen delivery system.
💡 Memory trick
Haemoglobin is the 'oxygen taxi': O2 boards at the lungs, gets off at the tissues.
BiologyLife ProcesseseasyGive two differences between arteries and veins.
Reveal answer ↓
What it is
Arteries carry blood away from the heart under high pressure; veins bring it back and have valves.
Answer
Arteries carry blood away from the heart, usually oxygenated (except the pulmonary artery), have thick elastic walls and no valves because blood flows under high pressure. Veins carry blood towards the heart, usually deoxygenated (except the pulmonary vein), have thinner walls and contain valves to prevent the backflow of low-pressure blood.
- •Arteries: away from heart, thick walls, no valves, high pressure
- •Veins: towards heart, thin walls, valves present, low pressure
Why learn this
It's basic to understanding blood pressure, heart attacks and how injections and IV drips work.
💡 Memory trick
Arteries = Away from the heart; Veins have Valves to stop backflow.
BiologyLife ProcessesmediumWhat is photosynthesis? Write its balanced equation and the conditions needed.
Reveal answer ↓
What it is
Photosynthesis is how green plants make their own food (glucose) from CO2 and water using sunlight.
Answer
Photosynthesis is the process by which green plants make their own food (glucose) from carbon dioxide and water using sunlight, releasing oxygen. The balanced equation is: 6CO2 + 6H2O -> C6H12O6 + 6O2. It requires chlorophyll (the green pigment), sunlight, carbon dioxide and water.
6CO2 + 6H2O -> C6H12O6 + 6O2
- •Green plants make glucose from CO2 and water using light
- •6CO2 + 6H2O -> C6H12O6 + 6O2
- •Needs chlorophyll, sunlight, CO2, water
- •Releases oxygen
Why learn this
It's the source of nearly all food and oxygen on Earth - the base of every food chain.
💡 Memory trick
6CO2 + 6H2O --(sunlight + chlorophyll)--> glucose + 6O2. Plants 'eat' light.