Important Questions (2 Marks): Life Processes - SSS 1 MCQ

Arteries are thick-walled blood vessels which pump blood at high pressure away from the heart. They do not have valves as their walls are highly muscular.

The root has further extensions which increase the surface area for absorption.
These extensions are called root hair, which is present in all types of roots.

Stomata, which are part of the epidermal system in plants, facilitate transpiration. Transpiration mainly occurs through these stomata located in the leaves.

Oxygenated blood carries O₂ to the various tissues, muscles, cells, et(c) from the lungs and heart, while deoxygenated blood carries CO₂ from the organs to the lungs which is removed from the body. In birds and mammals, it is essential to keep the oxygenated blood separated from the deoxygenated blood In this way, only highly oxygenated blood is sent out to the body's tissues for far more efficient diffusion into the cells of the body, giving them more 'fuel' to run cellular respiration in the mitochondria, to make ATP molecules to run the reactions that allow them to maintain body temperature in addition to running all of their metabolic reactions of the body. If they were not separated, it would probably take much longer to perform simple activities and metabolism would be reduced as a consequence.

Arteries are the blood vessels which carry oxygenated blood from the heart to the organs. It breaks up into several branches of capillaries before entering the organs. These capillaries again reunite to form venules and ultimately veins which carry the deoxygenated blood towards the heart.

The kidneys filter blood to remove urea and other wastes (A), maintain water balance (B), regulate salt levels (D), and form urine (E). However, they do not produce antibodies, which is the function of the immune system (B-lymphocytes)

The kidney is the main excretory organ in man. It helps in the filtration of blood and maintains osmoregulation. Accessory organs of excretion are liver, lungs, and skin. Small intestine and large intestine helps in the digestion of food whereas the heart is the main circulatory organ in the human body which helps in the transportation of blood.

When your systolic pressure is between 120 and 129 mm Hg and your diastolic pressure is less than 80 mm Hg, it means you have elevated blood pressure. Although these numbers aren't technically considered high blood pressure, you've moved out of the normal range.

The sugars, synthesized in leaves (as a result of photosynthesis) are translocated downwards, upwards, and laterally to storage organs mainly through phloem. These sugars are translocated in the form of sucrose.

The diastolic reading, or the bottom number, is the pressure in the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen. A normal diastolic blood pressure is lower than 80. A reading of 90 or higher means you have high blood pressure.

Hydrochloric acid (HCl) is not found in pancreatic juice; it is secreted by the stomach. Mucus is also not a digestive enzyme, but rather a protective substance lining the digestive tract. Pancreatic juice does contain the digestive enzymes lipase (for breaking down fats) and trypsin (a protease that breaks down proteins). 

Why other options are incorrect:

• (i) and (iv): Lipase and trypsin are both digestive enzymes found in pancreatic juice.
• (iii) and (iv): While mucus is not a digestive enzyme, trypsin is.
• (i) and (ii): Lipase is a digestive enzyme found in pancreatic juice, but hydrochloric acid is not. 

Stomach secretes the enzyme pepsin and pancreas produces trypsin. Both of them break down protein.

The correct answer is:
c) (i), (ii) and (iv)

Explanation:

In autotrophic mode of nutrition (like in green plants), organisms prepare their own food using simple substances from the surroundings through photosynthesis.

The main raw materials required are:

• (i) Carbon dioxide – from the atmosphere and Water – from the soil

• (ii) Chlorophyll – as the pigment necessary to capture sunlight

• (iv) Sunlight – as the energy source

Note:
Chlorophyll is not a "raw material" but a requirement for photosynthesis.
Nitrogen (iii) is essential for growth and protein synthesis, but not directly involved in the photosynthesis process.

Hence, option (c) is the most appropriate.

The pancreas contains all kinds of enzymes that can digest proteins, fats, and carbohydrates.

The nephron is the structural and functional unit of the kidney. It is responsible for filtering blood and forming urine through processes like filtration, reabsorption, and secretion.

Mucus is a viscous secretion that protects the inner lining of the stomach from the action of HCl.

Transpiration creates a suction force that helps in the upward movement of water through the xylem vessels in plants. This process is called transpiration pull.

The build-up of lactic acid in our muscles while running (less oxygen conditions) causes cramps.

Red blood cells (RBCs) contain hemoglobin, which binds to oxygen and transports it to various parts of the body.

- Organisms that can produce their own food from inorganic substances are called autotrophs.
- Autotrophs use processes like photosynthesis or chemosynthesis.
- Photosynthesis: Converts light energy into chemical energy in plants, algae, and some bacteria.
- Chemosynthesis: Utilizes chemical energy from inorganic compounds, common in bacteria in extreme environments.
- Autotrophs are essential in ecosystems as primary producers, forming the base of the food chain by supplying energy to heterotrophs.