CBSE Questions for Class 10 Biology Life Processes Quiz 2 - MCQExams.com

• The mode of nutrition in Amoeba is known as holozoic nutrition. It involves the ingestion, digestion, and egestion of food material with the help of pseudopodia. 
• Pseudopodia acts as an organ for locomotion or taking in food from its surroundings.

• The primary producers present at the first trophic level in an ecosystem are autotrophic.
• These autotrophs perform photosynthesis wherein they use carbon dioxide and water in the presence of sunlight and chlorophyll to produce carbohydrates.
• CO$$_2$$ (Carbon dioxide) + H$$_2$$O (Water) $$\rightarrow$$ C$$_6$$H$$_{12}$$O$$_6$$ (Glucose) + O$$_2$$ (Oxygen)
• So, the correct answer is option C.

Correct Option: D

Explanation:

• The nephron is the kidney's structural and functional unit.
• The huge volume of fluid goes through the glomerulus, where ultrafiltration occurs.
• Post the process of ultrafiltration, mineral reabsorption occurs in the proximal convoluted tubule, wherein, glucose, water, and amino acids are reabsorbed.
• Urine is concentrated deeper in Henle’s loop.
• Potassium and sodium are reabsorbed when the residual filtrate enters the distal convoluted tubule.
• In the collecting duct, the water is mostly reabsorbed. As the rest of the water and minerals are reabsorbed into the circulation, the urine produced is highly concentrated.

Although a large quantity of fluid is filtered every day by the nephrons in the kidneys, only about 1% of it is excreted as urine. The remaining 99% of the filtrate is reabsorbed into the blood.

• Pyruvic acid is the final product of glycolysis. Krebs cycle releases $$CO_2$$ and water. 
• Bacteria produces lactic acid via fermentation.
• Ethyl alcohol is produced as a result of fermentation in yeast, along with that, $$CO_2$$ is released as a by-product.
• So, the correct answer is option B.

• Green plants are autotrophic organisms because they can synthesize their own food by photosynthesis. 
• During photosynthesis energy from sunlight is converted into chemical energy in the form of organic compounds and oxygen is released as a by-product.
•  Animals, fungi and several bacteria are heterotrophic organisms and depend on organic compounds synthesized by autotrophs for their nutrition.
• So, the correct answer is 'Autotrophs'

• Organisms that cannot synthesize their own food are called heterotrophs. Heterotrophs depend directly or indirectly on autotrophs for their food.
• Autotrophs are the organism that can produce their own food using light, water, carbon dioxide, or other chemicals.
• Algae are autotrophs.

• The labeled portion depicted by the number 2 is the pulmonary artery that carries deoxygenated blood to the lungs from the right ventricle of the heart. 
• The labeled portion depicted by the number 4 is the pulmonary vein that returns oxygenated blood to the left atrium of the heart. 

• Light is essential for photosynthesis to take place. As the partially covered part doesn't get light to carry out photosynthesis, no starch is produced in them. This part when tested with Iodine solution gives pale colour, which indicates absence of starch. 
• The rest part of the Leaf which is not covered absorbs light and can perform photosynthesis. This part when tested with Iodine solution gives blue black colour, which indicates presence of starch.

• The covered leaf part with a black paper strip, when tested for presence of starch gives negative test i.e. there is no starch produced in them. 
• This case shows that light and water are essential for production of food (photosynthesis) in the plant. And as the covered part doesn't get any proper light, no starch is produced in that region of the plant.
• Hence, light is necessary for photosynthesis. Option "D" is correct.

• The circulatory system has several functions such as:

1. The transportation of substances
2. The removal of metabolic wastes.
3. Maintaining the body temperature
4. Protecting the body from certain diseases. 
5. Regulation of the body activities by transporting hormones.

• The formation of urea is the function of excretory system. 

Correct Option: B
Explanation: 

• The cardiac cycle has two phases of the heart beat-systole and diastole.

• The glomerulus is the blood capillary present in the bowman's capsule, where blood is filtered due to the pressure difference between afferent and efferent arteriole caused due to differences in their diameters. 
• The blood that comes into the bowman's capsule of the nephron is filtered i.e., without any blood corpuscles.