Respiration in Organisms Grade 7 Notes PDF

Respiration in Organisms NOTES Grade 7 Starter: Learning Objectives: List the functions performed by a cell in order to infer the need of energy for various processes. Outline cellular respiration in order to differentiate between...

Respiration in Organisms NOTES Grade 7 Starter: Learning Objectives: List the functions performed by a cell in order to infer the need of energy for various processes. Outline cellular respiration in order to differentiate between aerobic and anaerobic respiration. Analyze inhalation, exhalation and breathing rate in own body in order to examine the impact of various activities on breathing rate. Construct a cause-and-effect model of respiratory processes in animals and plants, as an extension of available resources and respiratory organs/features.  List the functions of a cell to determine the amount of energy required for various processes. Interpret the respiration process in cockroaches, earthworms, fish, and plants to predict the consequences of an insufficiency of respiratory organs or characteristics in animals or plants Let us learn new words (Write meaning of the words) Aerobic respiration Anaerobic respiration Breathing rate Cellular respiration Diaphragm Exhalation Gills Lungs Inhalation Spiracles Tracheae Ribs Let us read and write: 1. Why does an athlete breathe faster and deeper than usual after finishing the race? Ans: Athletes generally have a faster breathing rate as they require more energy for running or any physical exercise. In order to get a larger amount of oxygen, they breathe faster so that more energy can be synthesized. 2. List the similarities and differences between aerobic and anaerobic respiration.  Ans: 3. State aerobic and anerobic respiration with the help of an equation. Ans: a. Aerobic respiration takes place in the mitochondria and requires oxygen and glucose, and produces carbon dioxide, water, and energy. The chemical equation - C6H12O6 + 6O2 → 6CO2 + 6H2O+energy (glucose + oxygen -> carbon dioxide + water). b. Anaerobic respiration takes place in the cell cytoplasm in the absence of oxygen and produces lactic acid. The chemical equation- C6H12O6 -> 2C3H6O3 (Glucose -> Lactic acid). 4. Define Breathing rate. Ans: The number of times a person breathes in a minute is termed as the breathing rate. The normal breathing rate for an adult at rest is 12 to 20 breaths per minute. 5. Explain about inhalation and exhalation. Ans: Inhalation is when we take in air containing oxygen. Exhalation is when we give out air rich in carbon dioxide. They are the basic process of breathing.  During Inhalation, the lung volume increases. According to Boyle’s law, lung pressure reduces compared to atmospheric pressure. It makes the air rush into lungs. Afterwards, blood promptly transports the air containing oxygen to every part of the body. In the case of expiration, the lung volume decreases because of the elastic flinch of lung tissues. As a result, the pressure within the lungs increases compared to the outside pressure. It allows the air carrying carbon dioxide to push out of the body. 6. Draw the respiratory system in humans. Ans- 7. Why do we often sneeze when we inhale a lot of dust-laden air? Ans: There are tiny hairs all along our respiratory passageways (cilia) that filter dust and other particles out of the air we breathe. Sneezing or coughing is a result of the cilia  working together with mucous linings to expel the unwanted particles from your body. 8. Write a short note on lungs. Ans: The lungs are the main organs of the respiratory system. The tiny air bags in the lungs, the alveoli, are surrounded by small capillaries where the exchanges of oxygen and carbon dioxide takes place. The lungs also consist of elastic tissues that allows them to inflate (when inhaling) and deflate (when exhaling) without losing their shape. 9. Explain the process of respiration in earthworm. Ans: Earthworms breathe through their moist skin. They keep their skin moist by secreting mucus. It is very important to keep their skin surface moist for oxygen to get dissolved in it. 10. How does a fish respire? Ans: A majority of aquatic animals like fish and prawns breathe through special organs called gills. Gills are projections of the skin that help in using oxygen dissolved in water. Gills contain blood vessels which help in exchange of gases. 11. Write a short note on alternate modes of respiration in plants. Ans: Like animals and humans, plants also breathe. Plants do require oxygen to respire, the process in return gives out carbon dioxide. Unlike humans and animals, plants do not possess any specialized structures for exchange of gases, however, they do possess stomata (found in leaves) and lenticels (found in stems) actively involved in the gaseous exchange. During respiration, in different plant parts, significantly less exchange of gas takes place. Hence, each part nourishes and fulfils its own energy requirements. Consequently, leaves, stems and roots of plants separately exchange gases. During the process of respiration, oxygen is utilised, and carbon dioxide, water and energy are released as products. C6 H 12 O6= CO2+ H2 O +Energy *****************