PART - 2 - Unit V : CH - 16 Excretory Products and Their Elimination — BIOLOGY STD 11 Science — Question

Manish while performing a practical in laboratory on Grams stain observed that one type of bacteria stained dark blue or purple in colour, while the other type of bacteria did not retain the crystal violet dye even after staining again and again. Instead it keeps on loosing the dye on washing. He rushed to his teacher for showing the specimen.

His teacher explained that there is nothing to get worried about. As different kinds ofbacteria are found.

1. What is the basis of classifying bacteria.
2. What is the basic difference between Gram positive and Gram negative bacteria.
3. Name one Gram positive and one Gram negative bacteria.
4. What values are shown by Manish's teacher?

Describe the structure of the following with the help of labelled diagrams.
Nucleus

How does cytokinesis in plant cells differ from that in animal cells?

Make a labelled diagram of a plant cell. Compare animal cell with this.

What is a tissue? Describe different types of simple tissues in plants.

Give a brief account of mechanism of synaptic transmission.

Discuss "The respiratory pathway is an amphibolic pathway."

The mode of arrangements of sepals or petals in a floral bud is known as aestivation. Draw the various types of aestivation possible for a typical pentamerous flower.

Describe the structure of the membrane as proposed in fluid mosaic model.

Explain the difference between cilia and flagella. Draw a diagram and describe their internal structure.