1. Plant growth follows distinct phases: cell formation, enlargement, and maturation. 2. The initial phase involves meristematic cell division and the addition of new cells. 3. Newly formed cells elongate and undergo enlargement during the phase of cell enlargement. 4. Cell maturation follows, where cells differentiate into specialized types. 5. Growth rates vary across phases: … Read more
Macronutrients: Essential macronutrients, such as nitrogen, phosphorus, and potassium, play vital roles in plant development. Nitrogen is crucial for protein synthesis, and its deficiency leads to leaf yellowing and grain wrinkling. Phosphorus, a key component of cell membranes and proteins, causes red spots on leaves and delays seed germination when deficient. Potassium, abundant in growing … Read more
1. Plants utilize their root system to absorb minerals from the soil. 2. Charged particles, including positively charged cations and negatively charged anions, are taken up by the roots from the soil. 3. Active absorption, a process demanding metabolic energy, enables minerals to be absorbed against the concentration gradient. 4. ATP energy produced through root … Read more
Definition: Hydroponics involves growing plants in nutrient-rich water, either with or without the use of a mechanical support system like sand, gravel, or perlite. 1. Hydroponics, derived from the Greek words “hudor” (water) and “ponos” (work), is a technique where plants are cultivated without soil, receiving essential nutrients through a water-based medium. This involves creating … Read more
1. Stomatal transpiration is regulated by the turgidity of guard cells. 2. Turgor pressure, acting on the unevenly thickened guard cell wall, governs stomatal movement. 3. The elastic outer wall stretches, pulling the inner inelastic wall, causing stomatal opening. 4. Flaccidity of guard cells results in stomatal closure. 5.Osmotically active sugar increases guard cell osmotic … Read more
1. Introduced by Dixon and Jolly in 1894, this theory currently stands as the widely accepted explanation for the upward movement of sap in plants. 2. Grounded in two fundamental principles—cohesion and adhesion, along with transpiration pull—this theory delineates the mechanism behind sap ascent. 3. Cohesion and adhesion dynamics involve the cohesive force among water … Read more
1. Root hairs, originating as tubular extensions of epiblema cells, play a crucial role in absorbing capillary water from the soil. 2. The absorption of water involves three key physical processes: imbibition, diffusion, and osmosis. 3. Imbibition occurs as water molecules are adsorbed on the cell wall of the root hair, contributing to the overall … Read more
1. The absorption of water by plants is facilitated through the intricate network of root hairs embedded in the soil. 2. Root hairs, strategically located in the zone of absorption, play a vital role in the uptake of water and essential nutrients. 3. Originating as unicellular extensions, these root hairs are ephemeral structures formed by … Read more
Genetic variation refers to the diversity in DNA sequences among individuals within a population, occurring in both germ cells (sperm and egg) and somatic cells (all other cells). Genetic variations are caused by following factors: I. Mutation: • Definition: Sudden, permanent heritable changes. • Types: Gene mutation (point mutation), chromosome structure mutation, chromosome number mutation. • Effect: Alters … Read more
Isolation refers to the division of a species’ population into smaller units, where organisms in these subunits are hindered from interbreeding by barriers known as isolating mechanisms. Different type of reproductive isolation are as follows: I. Geographical Isolation: • Physical barriers like rivers, oceans, mountains, or glaciers divide the original population. • Organisms can’t cross these … Read more