Cell Cycle and Cell Division — BIOLOGY STD 11 Science — Question

Classify the frog. How is this creature beneficial for us?

Which one of the following characters is not typical of the class-Mammalia?

1. Seven cervical vertebrae.
2. Thecodont dentition.
3. Ten pairs of cranial nerves.
4. Alveolar lungs.

1. What is florigen?
2. Which hormone breaks seed dormancy? State the mechanism involved.

Write about Haldane effect. How does Haldane effect and Bohr effect complement each other?

What is meant by the term osmoregulation?

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?

Give two reasons why all minerals cannot be absorbed passively by the roots.

Describe the cortex region of dicot root.

Which one of these is viviparous?

1. Turtle
2. Running birds
3. Rabbit and whale
4. Bony fish

Assertion: Periplaneta Americana is nocturnal, omnivorous, household pest. Reason: It is because it acts as scavenger.

1. A is true but R is false.
2. A is false but R is true.
3. Both A and R are true and R is correct explanation of A.
4. Both A and R are true but R is not correct explanation of A.