Roman Saini is teaching live on Unacademy Plus
Q46. Which of the following cells can respire anaerobically? 1. Brain cells 2. Muscle cells Yeast 4. Stomach cells Choose the correct code. a. b. 2 and 3 only 1 and 2 only c. and 4 only d. 2 and 4 only
Answer: b Explanation: Yeasts are single-celled organisms. They respire anaerobically and during this process yield alcohol. They are, therefore, used to make wine and beer. Muscle cells can respire anaerobically when there is a temporary deficiency of oxygen such as during heavy exercise.
Q47. Breathing involves the movement of Rib cage 2 Diaphragm Windpipe Nostrils 4 Choose the correct code a. 1 and 2 only b.2 and 3 only c. and 4 only d. 1, 2 and 4 only
Answer: a Explanation: Breathing involves the movement of the diaphragm and the rib cage. Diaphragm is a large, muscular sheet that forms the floor of the chest cavity. During inhalation, ribs move up an outwards and diaphragm moves down. This movement increases space in our chest cavity and air rushes into the lungs. The lungs get filled with air. During exhalation, ribs move down and inwards, while diaphragm moves up to its former position. This reduces the size of the chest cavity and air is pushed out of the lungs
Q48. Which of the following structures helps the insects in breathing? 1. Spiracles Lungs 3. Trachea 4. Skin Choose the correct code. a. 1 and 2 only b. 2 and 3 only c. 1 and 3 only d. and 4 only
Answer: c Explanation: Insects have small openings called spiracles on their body. These spiracles are connected to a series of air-tubes called trachea. Oxygen rich air rushes through spiracles into the tracheal tubes, diffuses into the body tissue, and reaches every cell of the body. Similarly, carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles.
Q49. Which of the following organisms breathes through skin? a. Insects b. Earthworms C. Snakes Lizards
Answer: b Explanation: Earthworms breathe through their skin, which feels moist and slimy on touching. Gases can easily pass through it.
Q50. Frogs can respire through Lungs 2. Skin 3. Spiracles 4. Gills Choose the correct code. a. 1 and 2 only b.2 and 3 only c. 1 and 3 only d. and 4 only
Answer: a Explanation: Frogs can breathe through lungs as well as the moist skin.
Q51. Roots of plants take up oxygen for respiration from Atmosphere . ater in the soil a. C. Air in the soil d Roots don't respire
Answer: c Explanation: Roots take up air from the air spaces present between the soil particles.
Answer: c Explanation: Overwatering leads to decreased availability of oxygen to the roots, which depend on soil air for respiration and thus overwatering harms the plant.
Q54. Which of the following organisms do not have a circulatory system? 1.Sponges 2. 3. 4. Snakes Choose the correct code a. b. 1and 3 only C. d. Cockroaches 1 and 2 only 2 and 3 only
Answer: c Explanation: Self-explanatory
Q56. Which of the following organs is not a part of excretory system? a. Ureters b. Urethra C. Penis d. Urinary bladder
Answer: c Explanation: Excretory system consists of kidneys, ureters, urinary bladder and urethra only
Q58. Which of the following organisms and their chief excretory product is correctly matched? Man- uric acid Fish- ammonia Birds urea 3 Choose the correct code a. b. C. d. 2 and 3 only 1 only 2 only 1 and 2 only
Q59. Dialysis is a clinical procedure performed in patients suffering from Kidney failure Heart failure C. Liver failure d. Urea toxicity a.
Q60. Which of the following helps in transport of water and minerals from roots in plants? a. Phloem b. C. Arteries d. Veins Xylem
Answer: b Explanation: The xylem forms a continuous network of channels that connects roots to the leaves through the stem and branches. It transports water and minerals to the entire plant. Phloem transports food prepared by the leaves to all other parts of the plant.