Class Notes NCERT Solutions for CBSE Students
Question: All living things take in oxygen. What function does oxygen perform on the body?
Answer: Oxygen combines with the food (glucose) and converts it into energy. This energy is utilized for various life process.
Question: Name four waste products that we excrete.
Answer: The four waste products that we excrete are:
- Urine
- Sweet
- Stool
- Carbon dioxide.
Question: List four different ways in which organisms carry out exchange of gases for respiration, with one example each.
Answer:
- Animals like cow, dogs and birds breathe like human beings.
- Earthworm breathe through skin.
- Cockroaches and many other inseds breaths through several holes its body.
- Fish breathe through gills.
- Plants exchange gases which take place through the tiny stomata in their laves.
Question: List three ways in which living things reproduce, giving one example of each.
Answer: Three ways are:
- By seed – wheat, fruits etc.
- By baby – human being, dog, cow etc.
- By eggs – snakes, hen etc.
Question: Explain giving examples what you mean by a ‘species’.
Answer: A Species is a group of similar living organisms that have similar body parts live in the same habitat, eat the kind of food and reproduce among themselves.
Question: Plants take in oxygen and give out carbon dioxide during respiration all that time. Why do we them say that plants supply oxygen to the air.
Answer: During day time they produce oxygen much more then they need for respiration. So they excrete out excess oxygen.
Question: What are cells? Are all living things made up of cells?
Answer: Living things are made up of cells, they grow, have a definite lifespan, reproduce, respond to stimuli, need food, respire and excrete.
Question: Give an example of a stimulus and a response.
Answer: When you accidentally touch a hot utensil. you quickly withdraw your hand. The withdrawing of your hand is a response. The cause of this response is called the stimulus which in this case is the hot utensil.
