Factors that affecting the plant growth MCQ - Practice Questions with Answers

The growth of the plants is affected by the following external features:

1. Temperature plays an important role in the growth of plants. The minimum, optimum and maximum temperature varies from species to species. As the temperature increases above the minimum, growth is accelerated until the optimum temperature is attained, when the growth gets slower and is completely retarded.

2. Light also affects the growth and development of the plant. Several factors of light like light intensity, duration of light and quality of light influences several physiological processes like the movement of stomata, chlorophyll synthesis, the temperature of aerial organs, formation of anthocyanin, absorption of minerals streaming of protoplasm and rate of transpiration.

3. Duration of light also affects plant growth as it affects the rate of photosynthesis. For instance, during winter when the days are short, the growth is very slow, while, it increases during summers when the days are longer.

4. The plants with lesser availability of oxygen show retarded growth while it is vice versa in the presence of ample oxygen.

5. Water is very important for plants and inadequate water results in poor growth. Plants grow well only in the presence of optimum water. Plants respond to deficiency of moisture as well.

6. Soil nutrients, their quantity and nature also affect the growth of the plant. For Luxuriant Growth, it is important to have an adequate amount of nutrients.

The following internal factors affect the growth of the plant:

1. There are several classes of growth regulators. Some promote the growth like Auxins, Florigen, Cytokinins, Gibberellins, etc. while some are growth inhibitors like ethylene, abscisic and chlorocholine chloride.

2. The ratio of carbohydrates and nitrogen also govern the growth of plants. Presence of more carbohydrates as compared to nitrogen facilitates vegetative growth, fruiting and flowering while the presence of more nitrogenous compounds results in poor vegetative growth.

3. Genotypes are responsible for controlling all the metabolic activities, growth and development of a plant. Expression of genes in the correct sequence is controlled by two things, i.e. environment and genes.