Body Fluids and Circulation — BIOLOGY STD 11 Science — Question

Biology teacher was teaching cell cycle in the class. She taught that cell is the basis from which life exists. Also explained well about cell cycle. Robin who was a bright student was facing difficulties in understanding the topic he reached home and asked her sister who is a student of biology in a college about details of cell cycle and cell theory. She explained him that according to cell theory, cells arise from pre-existing cells and the process involved is cell division. Sexually reproducing organisms start their life from a single cell, called zygote, and cell divisions do not stop with the formation of a mature organism, but continue throughout the life.

1. What is meant by cell cycle?
2. Which is the actual phase of cell division?
3. When (at what phase) do the cell organelles duplicate?
4. What values are reflected from the Robin's concern?

Diagrammatically show the types of symmetry in animals.

Differentiate between dendrites and axons.

Differentiate between
Glycolysis and Krebs’ cycle

Tendrils of grapevines are homologous to the tendril of pumpkins but are analogous to that of pea. Justify the above statement.

What is the advantage of development of seed habits in seed plants?

Differentiate between primary and secondary growth in plants.

Draw a labelled diagram showing reabsorption and secretion of major substances at different partsof the nephron.

List the various types of nephridia in earthworm. Briefly describe the functioning of nephridia during excretion.