Chemical Coordination and integration — BIOLOGY STD 11 Science — Question

Demonstrate and explain the formation of annual ring in the transverse section of the stem.

What is the difference between monocot and dicot leaves?

Complete the flow chart for cyclic photophos-phorylation of the photosystem.

Write short notes on:

1. Erythrocytes.
2. Leucocytes.
3. Structure of Heart.

Does pyruvic acid enter the 'Krebs' cycle directly?

While teaching cell division in the class, teacher told that during meiosis, the chromosome number is reduced to half of the parent, whereas during mitosis, the number remains the same. Seema was not able to recognise what teacher explained in the class and asked her elder brother, a botany student, the need of reducing chromosomes during gamete formation and what will happen if chromosome number will not reduced to its half. He explained the concept in detail to Seema.

1. In which part of the organisms does meiosis occur?
2. How does meiosis help in evolution?
3. Give the significance of meiosis.
4. What value is expressed in the behaviour of Seema's elder brother?

Study the curve given below and answer the questions asked:

1. What is this curve known as?
2. What does 'C' depict in the curve?
3. The effect of which factors can be studied with the help of this curve?

1. What is termed as first messenger and second messenger in the target cells.
2. How do protein hormones act on target cells?

Differentiate between macronutrieints and micronutrients with an example of each.

Respiratory pathway is believed to be a catabolic pathway. However, nature of TCA cycle is amphibolic. Explain.