To explore how hormones function, researchers have begun to transform plants with particular genes. In one experiment, a gene involved in cytokinin synthesis was introduced into tobacco plants. Which one of the following results would be expected?
a. Individuals produced more lateral branches.
b. Stems grew extremely tall and slender.
c. Roots were incapable of responding to gravity.
d. Stomata were closed most of the time.

Verified step by step guidance

1. Understand the role of cytokinins: Cytokinins are a class of plant hormones that promote cell division and growth, particularly in the shoots and leaves. They are known to influence various aspects of plant development, including the stimulation of lateral bud growth.
2. Consider the effects of increased cytokinin synthesis: Introducing a gene involved in cytokinin synthesis into tobacco plants would likely lead to an increase in cytokinin levels. This could enhance the hormone's typical effects on plant growth and development.
3. Evaluate the options based on cytokinin function: Given the role of cytokinins in promoting lateral bud growth, option (a) 'Individuals produced more lateral branches' aligns with the expected outcome of increased cytokinin activity.
4. Analyze the other options: Option (b) 'Stems grew extremely tall and slender' is more characteristic of gibberellins, another plant hormone. Option (c) 'Roots were incapable of responding to gravity' relates to auxins, which are involved in gravitropism. Option (d) 'Stomata were closed most of the time' is associated with abscisic acid, which regulates stomatal closure.
5. Conclude with the most likely result: Based on the understanding of cytokinin function, the expected result of introducing a gene involved in cytokinin synthesis into tobacco plants would be the production of more lateral branches, as described in option (a).

Key Concepts

Cytokinin Function

Cytokinins are a class of plant hormones that promote cell division and growth, particularly in shoots and leaves. They are known to influence the development of lateral branches by stimulating the growth of axillary buds. Understanding cytokinin function is crucial for predicting how genetic modifications affecting cytokinin synthesis might alter plant morphology.

Genetic Transformation in Plants

Genetic transformation involves introducing new genes into a plant's genome to alter its characteristics. This process can be used to study hormone functions by modifying hormone synthesis pathways. In the context of the question, transforming tobacco plants with a gene for cytokinin synthesis allows researchers to observe changes in growth patterns and development.

Plant Hormone Interactions

Plant hormones often interact with each other to regulate growth and development. Cytokinins, for example, can work in conjunction with auxins to balance root and shoot growth. Understanding these interactions helps predict outcomes of genetic modifications, such as increased lateral branching due to enhanced cytokinin activity, as opposed to other growth changes like stem elongation or root behavior.