HSC Science कक्षा १२ - Tamil Nadu Board of Secondary Education Question Bank Solutions for Botany

The plant of this group are adapted to live partly in water and partly above substratum and free from water

Ophrys an orchid resembling the female of an insect so as to able to get pollinated is due to phenomenon of

A free-living nitrogen-fixing cyanobacterium which can also form a symbiotic association with the water fern Azolla

In a fresh water environment like pond, rooted autotrophs are

Strong, sharp spines that get attached to animal’s feet are found in the fruits of

Sticky glands of Boerhaavia and Cleome support

Why are some organisms called as eurythermals and some others as stenohaline?

The organic horizon is generally absent from agricultural soils because tilling, e.g., plowing, buries organic matter. Why is an organic horizon generally absent in desert soils?

Soil formation can be initiated by biological organisms. Explain how?

Sandy soil is not suitable for cultivation. Explain why?

Describe the mutual relationship between the fig and wasp and comment on the phenomenon that operates in this relationship.

What is thermal stratification? Mention their types.

What is myrmecophily?

What is a seed ball?

What is co-evolution?

Explain Raunkiaer classification in the world’s vegetation based on the temperature.

Explain different types of hydrophytes with examples.

What are the advantages of seed dispersal?

Describe the dispersal of fruit and seeds by animals.

Read the following statements and fill up the blanks with the correct option.

1. Total soil water content in soil is called ______
2. Soil water not available to plants is called ______
3. Soil water available to plants is called ______