Samacheer Kalvi solutions for Biology (Botany) [English] Class 12 TN Board chapter 6 - Principles of Ecology [Latest edition]

Arrange the correct sequence of ecological hierarchy starting from lower to a higher level.

Ecology is the study of an individual species is called

1. Community ecology
2. Autecology
3. Species ecology
4. Synecology

A specific place in an ecosystem, where an organism lives and performs its functions is

Read the given statements and select the correct option.

1. Hydrophytes possess aerenchyma to support themselves in water.
2. Seeds of Viscum are positively photoblastic as they germinate only in presence of light.
3. Hygroscopic water is the only soil water available to roots of plants growing in soil as it is present inside the micropores.
4. High temperature reduces use of water and solute absorption by roots.

Which of the given plant produces cardiac glycosides?

Read the given statements and select the correct option.

1. Loamy soil is best suited for plant growth as it contains a mixture of silt, sand, and clay.
2. The process of humification is slow in the case of organic remains containing a large amount of lignin and cellulose.
3. Capillary water is the only water available to plant roots as it is present inside the micropores.
4. Leaves of shade plant have more total chlorophyll per reaction centre, low ratio of chl a and chl b are usually thinner leaves.

Read the given statements and select the correct option.

Statement A: Cattle do not graze on weeds of Calotropis.

Statement B: Calotropis have thorns and spines, as a defense against herbivores.

In soil water available for plants is

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 ______

Column I represent the size of the soil particles and Column II represents the type of soil components. Which of the following is the correct match for the Column I and Column IL

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

Identify the A, B, C, and D in the given table

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

Pedogenesis refers to

Mycorrhiza promotes plant growth by

Which of the following plant has non-succulent xerophytic and thick leathery leaves with a waxy coating

In a fresh water environment like pond, rooted autotrophs are

Match the following and choose the correct combination from the options given below:

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

Sticky glands of Boerhaavia and Cleome support

Define ecology.

What is ecological hierarchy?
Name the levels of ecological hierarchy.

What are ecological equivalents? Give one example.

Distinguish habitat and niche

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

‘Green algae are not likely to be found in the deepest strata of the ocean’. Give at least one reason.

What is Phytoremediation?

What is Albedo effect and write their effects?

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.

Lichen is considered as a good example of obligate mutualism. Explain.

What is mutualism? Mention any two examples where the organisms involved are commercially exploited in modern agriculture.

List any two adaptive features evolved in parasites enabling them to live successfully on their host?

Mention any two significant roles of predation plays in nature.

How does an orchid Ophrys ensure its pollination by bees?

Water is very essential for life. Write any three features for plants that enable them to survive in a water-scarce environment.

Why do submerged plants receive weak illumination than exposed floating plants in a lake?

What is vivipary? Name a plant group that exhibits vivipary.

What is thermal stratification? Mention their types.

How is rhytidome act as the structural defense by plants against fire?

What is myrmecophily?

What is a seed ball?

How is anemochory differ from zoochory?

What is co-evolution?

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

List out the effects of fire on plants.

What is the soil profile? Explain the characters of different soil horizons.

Give an account of various types of parasitism with examples.

Explain different types of hydrophytes with examples.

Enumerate the anatomical adaptations of xerophytes.

List out any five morphological adaptations of halophytes.

What are the advantages of seed dispersal?

Describe the dispersal of fruit and seeds by animals.