The Living World — BIOLOGY STD 11 Science — Question

What is the significance of step-wise release of energy in respiration?

Write the characteristics of heartwood and sapwood.

Describe the main excretory organs found in invertebrate animals.

Akanksha, while walking in the garden in the morning with her mother observed two water drops falling on the ground. She thought that it is raining. Being curious, she started finding the source of the watery fluid. Then she observed drops falling from the leaves tip. She asked her mother, who was a botanist about this. The mother explained her that it is not due to the rain instead the water drops are dripping due to the phenomenon called guttation.

1. What are hydathodes? Why are these called water glands?
2. Where are hydathodes present?
3. Name the process of water loss occurring via hydathodes.
4. What value is displayed by Akanksha's nature?

Give the cause for the Heart sounds.

Who was the first to attempt a more scientific basis for classification of living organisms? How did he classify plants and animals?

Differentiate between primary and secondary growth in plants.

Each plant or group of plants have some phylogenetic significance in relation to evolution: Cycas, one of the few living members of gymnosperms is called as the 'relic of past'. Can you establish a phylogenetic relationship to Cycas with any other group of plants that justifies the above statement?

Answer the following questions with reference to the anatomy of dicot stem

1. Type of cells present in the hypodermis.
2. Why is the endodermis layer referred to as starch sheath?
3. Why are the vascular bundles present here referred to as 'open' and 'conjoint'?

List the hormones secreted by the following: Hypothalamus.