Question

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

Short answer

The correct answer is (c) Both (a) and (b). Both chemical regulators and genetics are required for plant development.

Step-by-step solution

Understanding chemical regulators

Chemical regulators in the context of plant development often refer to hormones or other signaling molecules. They regulate numerous growth and developmental events in plants, such as cell division, elongation, differentiation, and responses to environmental stimuli.

Understanding genetic factors

Genes also play a critical role in plant development. They are composed of DNA, which holds the instructions needed for an organism's development and functioning. Genetic factors regulate the plant's development by controlling the production of proteins that determine the biochemical and physical nature of cells and help control the organism's growth and development.

Answering the question

Given that both chemical regulators (hormones and signaling molecules) and genetic factors (genes that control protein production) are vital for plant development, the answer is that both are required.

Key concepts

Chemical Regulators

Chemical regulators are vital molecules in plant development. They serve as messengers that tell different parts of the plant what to do and when to do it. Chemical regulators, also known as phytohormones, include auxins, gibberellins, cytokinins, ethylene, and abscisic acid, among others. These molecules control a wide range of processes in plants.

• Auxins are crucial for cell growth and elongation, particularly in the tips of plants, which helps them grow upwards towards the light.
• Gibberellins are important for seed germination, stem elongation, and flowering.
• Cytokinins promote cell division and can delay aging in leaves.
• Ethylene plays a role in fruit ripening and response to stress.
• Abscisic acid primarily acts as a growth inhibitor and helps plants cope with stress by closing stomata during water scarcity.

These chemical regulators are essential because they balance growth and response to environmental changes, ensuring plants grow optimally.

Genetic Factors

Genetic factors are just as critical as chemical regulators in the development of plants. The DNA within plant cells holds the genes that encode proteins, which carry out most of the functions in a plant’s body. Each gene can be turned on or off, much like a switch, to ensure the proteins are produced when needed.

• Genes control the synthesis of enzymes that catalyze various biochemical reactions in plants.
• They also determine the structural features of plants, such as leaf shape, flower color, and root architecture.
• Genetic expression helps plants adapt to their environments, potentially conferring resistance to diseases or tolerance to harsh conditions.

Together, genetic factors provide the blueprint for all plant development processes, ensuring the correct formation of tissues and organs.

Hormones in Plants

Hormones in plants are a subset of chemical regulators, responsible specifically for influencing plant growth and development. They work in minute quantities but can profoundly affect plant physiology. The action of plant hormones is specific: they can either stimulate or inhibit processes, based on the plant’s needs and the external environment.

• The interaction between different hormones, such as the ratio of auxin to cytokinin, can determine whether a plant grows new roots or shoots.
• Plant hormones can mediate between environmental stressors and plant responses, ensuring plants can adapt and survive in varied conditions.
• They also coordinate complex processes like senescence, where a plant or part of it ages and eventually dies, which is essential for recycling nutrients within the plant.

Understanding plant hormones is crucial for agricultural practices, as manipulating hormone levels can improve crop yields and resilience.

Cell Differentiation

Cell differentiation in plants is the process by which generic plant cells become specialized in structure and function. This specialization is essential for forming different tissues and organs, such as leaves, flowers, and roots, each with unique roles in the plant’s survival.

• Cell differentiation is guided by both genetic instructions and chemical regulators, ensuring each cell type develops where and when it is needed.
• Differentiated cells in plants create a versatile structure that supports photosynthesis, water and nutrient transport, and reproduction.
• Processes like vascular tissue formation in roots and stems involve complex differentiation, establishing systems for nutrient transport throughout the plant.

Hence, cell differentiation is integral to the development and functionality of a plant, allowing it to grow and respond to its environment effectively.

Plant Growth

Plant growth involves both cellular proliferation and expansion, and is a dynamic process heavily influenced by the interplay between chemical regulators and genetic factors. Growth starts from seed germination and continues through the plant's life cycle, adapting to internal and external cues.

• Cell division provides new cells necessary for growth, initiated by hormones like auxins and cytokinins.
• Plant growth is directional, often oriented by factors like light (phototropism) and gravity (gravitropism).
• Genetic factors play a pivotal role by determining where growth occurs, ensuring the plant develops correctly shaped leaves, stems, and roots.

The process of plant growth is essential for replenishing plant tissues and enabling reproduction, affecting ecosystems and agriculture profoundly.