H. Answer these questions.
1. Under what conditions does anaerobic respiration occur?
2. State the role of diaphragm and rib muscles in breathing.
3. Explain the mechanism of breathing in humans.
4. Describe the process of inhalation of air into the lungs.
5. How does exchange of gases take place in human body?
6. Give differences in the composition of air being inhaled and exhaled.
7. What is the use of oxygen supplied to the cells of living organisms?
8. What material is used during respiration? Describe respiration in plants.
Answers
Answer:
(1)Anaerobic respiration transfers energy from glucose to cells. It occurs when oxygen is not present. It transfers large amounts of energy quickly.
(2)The diaphragm is attached to the base of the sternum, the lower parts of the rib cage, and the spine. As the diaphragm contracts, it increases the length and diameter of the chest cavity and thus expands the lungs. The intercostal muscles help move the rib cage and thus assist in breathing.
(3)The mechanism of breathing involves two main processes: inspiration and expiration. Inspiration occurs when the diaphragm and the external intercostal muscles contract. The contraction or relaxation of muscles around the lungs changes the entire volume of air inside the lungs, and so does the pressure.
(4)When you breathe in, or inhale, your diaphragm contracts and moves downward. This increases the space in your chest cavity, and your lungs expand into it. The muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.
(5)During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs. This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
(6)Inhalation is the process of intake of air into lungs, whereas exhalation is the process of letting air out from lungs. The composition of air which is inhaled is oxygen and nitrogen mix, while the composition of air which is exhaled is carbon dioxide and nitrogen mix.
(7)Your body cells use the oxygen you breathe to get energy from the food you eat. This process is called cellular respiration. During cellular respiration the cell uses oxygen to break down sugar. Breaking down sugar produces the energy your body needs.
(8)photosynthesis is the process where light energy is converted into chemical energy stored in glucose that can later be used in respiration. Photosynthesis occurs on the green parts of the plant that contain chlorophyll.
During respiration, plants consume food to keep plant cells alive while during photosynthesis, plants create their own food.