Roman Saini is teaching live on Unacademy Plus
Q1. Which of the following organisms are autotrophs? 1. Algae 2. Green plants Fungi Choose the correct code. a. 1 and 2 only b. 2 and 3 only c. 1 ad 3 only d. 1, 2 and 3
Answer: a Explanation: The mode of nutrition in which organisms make food themselves from simple substances is called autotrophic (auto = self, trophos = nourishment) nutrition. Algae and green plants prepare their own food using photosynthesis. They are autotrophs. Fungi on the other hand cannot prepare their own food and are not autotrophs.
Q2. Plants take carbon dioxide from air through Roots Fruit Stem Stomata C. d.
Answer:d Explanation: Carbon dioxide from air is taken in through the tiny pores present on the surface of the leaves. These pores are surrounded by 'guard cells'. Such pores are called stomata.
03.In desert plants, most of the photosynthesis takes place in 03. In desert plants, most of the photosynthesis takes place in a. Leaves b. Roots C. C. Stem d. Spines
Answer: c Explanation: The desert plants have scale- or spine-like leaves to reduce loss of water by transpiration. These plants have green stems which carry out photosynthesis.
Q4. Why do we add nitrogenous fertilizers to soil when nitrogen is so abundant in the atmosphere? a. Because atmospheric nitrogen is not good for plant health so plants don't absorb it. b. Because atmospheric nitrogen cannot be absorbed as such by the c. Because atmospheric nitrogen is absorbed slowly through stomata d. ecause a plants. and plants require a lot of nitrogen. d. Because atmospheric nitrogen is too light in weight and is not available at the level of plant height.
Answer:b Explanation: Atmospheric nitrogen cannot be absorbed directly by the plants. Soil has certain bacteria that convert gaseous nitrogen into a usable form and release it into the soil. These soluble forms are absorbed by the plants along with water. Nitrogenous fertilizers are added to the soil to make usable nitrogen available to the plants.
Q5. Fungi are able to grow on almost all kinds of organic matter. Where do the fungi growing on a piece of bread kept in a closed room, come from? a. Fungal spores, which are present everywhere. b. Fungi grow by themselves from organic matter. c. Fungi are present on all kinds of organic matter and they just need moisture to grow and become detectable by naked eye. Fungi cannot grow on organic matter placed in a closed room d. .
Answer: a Explanation: The fungal spores are generally present in the air. When they land on wet and warm things they germinate and grow.
Q6. Lichens is a symbiotic association between a. Plants and fungi b. Algae and fungi c. Bacteria and algae d. Plants and algae
Answer:b Explanation: In organisms called lichens, a chlorophyll-containing partner, which is algae, and a fungus live together. The fungus provides shelter, water and minerals to the alga and, in return, the alga provides the food which it prepares by photosynthesis.
Answer: b Explanation: Bacterium called Rhizobium can take atmospheric nitrogen and convert it into a soluble form. But Rhizobium cannot make its own food. So it lives in the roots of gram, peas, moong, beans and other legumes and provides them with nitrogen. Most of the pulses (dals) are obtained from leguminous plants. In return, the plants provide food and shelter to the bacteria. In organisms called lichens, a chlorophyll-containing partner, which is algae, and a fungus live together. The fungus provides shelter, water and minerals to the alga and, in return, the alga provides the food which it prepares by photosynthesis.
Q9. The saliva breaks down a. Proteins into peptides. b. Starch into simple sugars. c. Fats into fatty acid and glycerol. d. t has no digestive activity.
Answer:d Explanation: The inner lining of the stomach secretes mucous, hydrochloric acid and digestive juices. The mucous protects the lining of the stomach. The acid kills many bacteria that come along with the food and makes the medium in the stomach acidic and helps the digestive juices to act. The digestive juices break down the proteins into simpler substances.
Q11. Digestive enzymes of stomach convert a. Starch into simple sugars. b. Fats into fatty acid and glycerol. c. t has no digestive activity d. Proteins into simpler substances
Answer:d Explanation: Pepsin is the digestive enzyme secreted by stomach. It helps in converting proteins into simpler substances.
Q13. Pancreatic juices help in the digestion of 1 Carbohydrates Fats Proteins Vitamins 4 Choose the correct code. a. 1 and 2 only b.2 and 3 only c. 1, 2 and 3 d. 1, 2, 3 and 4
Q14. Which of the following organs is involved in digestion of carbohydrates, fats as well as proteins? Stomach Small intestine 2 3 Large intestine 4 Pancreas Choose the correct code. a. 1 and 2 only b. 1 and 3 only c. 2 and 4 only d. 3 and 4 only
Q15. Large intestine is involved in Absorption of salt and water Absorption of fats b. C. Digestion of fats d. Absorption of amino acids
Answer: a Explanation: The large intestine is wider and shorter than small intestine. Its function is to absorb water and some salts from the undigested food material. The remaining waste passes into the rectum and remains there as semi-solid faeces. The faecal matter is removed through the anus from time-to-time. This is called egestion.