Problem 83 - Objective Biology for NEET

Question

Intracellular factor required for development in plant include (a) Chemical regulators (b) Genetic (c) Both (a) and (b) (d) None of these

Step-by-Step Solution

Answer

The correct answer is (c) Both (a) and (b). Both chemical regulators as well as genetics are required for intracellular development in plants.

Step 1: Understanding the role of chemical regulators

Chemical regulators, such as hormones and chemical signals, play a significant role in plant development, as they control vital processes like growth, differentiation, and response to environmental conditions.

Step 2: Understanding the role of genetics

Genetics too, plays a crucial role in plant development. The genetic makeup of a plant determines its inherent traits and characteristics including size, flower color, seed production etc. Therefore, genetics is a key factor in plant development.

Step 3: Combining the roles of chemical regulators and genetics

Given that both chemical regulators (hormones for instance) and genetics play pivotal roles in plant development, it's quite evident that both factors are required intracellularly for plant development.

Key Concepts

Chemical Regulators in Plants

In plants, chemical regulators such as hormones and signaling molecules are crucial for coordinating and managing almost every aspect of growth and development. These substances control processes like germination, flowering, fruiting, and even how a plant reacts to stress. For instance, the plant hormone auxin is responsible for promoting cell elongation, which affects stem growth and bending towards light. Another example is ethylene, which influences fruit ripening and leaf abscission. These regulators are like the plant's internal communication system, transmitting vital information from cell to cell to ensure the organism grows and responds appropriately to its environment.

Understanding chemical regulators is key for students tackling plant biology, as they must recognize the diverse roles these substances play. It helps to personify them as 'messengers', delivering instructions to different parts of the plant to maintain its life cycle and adapt to changing conditions.

Plant Genetics

Genetics is the scientific study of heredity and variation in organisms, and in plants, this involves understanding how genetic information is passed from one generation to the next and how these genetic instructions are converted into physical traits. Plant genetics covers a range of topics from the genetic control of simple characteristics, like flower color governed by Mendelian genetics, to complex traits such as drought resistance, which may involve many genes interacting with the environment.

To grasp plant genetics, students should familiarize themselves with core concepts such as DNA, genes, alleles, and chromosomes. DNA carries the genetic instructions, genes are specific sequences of DNA that code for traits, alleles are different versions of a gene, and chromosomes are structures within cells that organize and carry these genetic materials. By understanding these fundamentals, students can appreciate how a plant's genetic makeup is a blueprint that directs its growth and development.

Plant Hormones

Plant hormones are natural chemicals that regulate the growth, development, and responses of plants to their environment. They are also known as phytohormones, and unlike in animals, these hormones are not produced in specific glands but are instead produced in various parts of the plant including stems, leaves, and roots. There are several major groups of plant hormones, each with their unique functions.

For example, auxins, are responsible for stimulating stem elongation, root initiation, and fruit development. Gibberellins promote stem growth and help in seed germination. Cytokinins are involved in cell division and growth, while abscisic acid is essential for maintaining water balance and facilitating the response to stress. Lastly, ethylene, a gas hormone, controls fruit ripening and leaf fall. Students learning about plant hormones should recognize how they interact in complex networks to finely tune the physiology of a plant, ensuring survival and reproduction.