Respiration In Plants — BIOLOGY STD 11 Science — Question

Describe the features of exoskeleton of cockroach.

What is the role of second messenger in protein hormone action?

What is the structural and functional unit of kidney called? Make a labelled diagram of it.

Dark reactions are dependent on light yet are called dark reactions. Justify.

1. When is a mineral element considered toxic in plant nutrition?
2. Why are the symptoms of toxicity difficult to identify?

In a class, teacher taught about the significance of water intake during summers. Teacher told children that water intake is valuable for healthy living and for proper digestion and excretion. Drinking enough water directly or through food helps the kidneys in their proper working.

1. What is osmoregulation?
2. Why we generally urinate fewer times in summer than in winter and the urine passed is usually thicker. Give the reason behind this statement.

While teaching about the chemistry of life, teacher emphasised that carbohydrates, fats, proteins, vitamins and minerals are important for life in addition to water. Akash was under the impression that fats are not good for body and high cholesterol content generally causes heart related and other problems. Therefore, he asked his father who is a doctor about the role of fats in living organisms.

1. What are fats?
2. What is the average percentage of fats present in a cell?
3. How many fatty acid residues are found in one molecule of fat?
4. What values are indicated from Akash's character?

Why is there a decrease in the rate of photosynthesis at high light intensities?

In which of the following notochord is present in embryonic stage?

1. All chordates.
2. Some chordates.
3. Vertebrates.
4. Non-chordates.