Plant Growth and Development — BIOLOGY STD 11 Science — Question

Metabolism is a defining feature of all living organisms without exception. Isolated metabolic reactions in vitro are not living things but surely living reactions. Comment.

Kritika's biology teacher explained the different phases of plant growth in her class. She taught that growth of plants takes place in three successive steps or phases from germination to maturation phase. Kritika reached home and asked her elder sister, a biology post-graduate student to clarify the phases in detail. Kritika's sister told her that she will explain the complete process with the help of experimentation. She took few seeds of pea and germinated them on a circular filter paper, soaked with water in a petri-dish. After two days of growth, she picked up a couple of seedlings with straight radicle and marked it from tip to base with the help of a waterproof ink and again placed the seedlings on moist filter paper to allow them to grow.

1. Mention different phases of growth in plants?
2. List the conditions required for growth.
3. What values are reflected from nature of Kritika's sister?

With respect to rib cage, explain the following:
Bicephalic ribs.
True ribs.
Floating ribs.

What is the source of energy for muscle contraction?

(i) Write three differences between protein hormones and steroid hormones.
(ii) Draw a labelled diagram depicting the mechanism of hormone action.

Give a diagrammatic representation of ATP synthesis.

Describe briefly :
Sigmoid growth curve

Give a brief account of structure and functions of Endoplasmic Reticulum.

How many vertebrae in all do we have? Categorise them on the basis of their location giving the specific number in each category.

Differentiate between:
Actin and myosin filament.