Problem 198 - Objective Biology for NEET

Question

Assertion: Ethylene increases the yield in cucumber. Reason: Ethylene promotes female flower in cucumber.

Step-by-Step Solution

Answer

Both the Assertion and the Reason are true, and the Reason is the correct explanation for the Assertion.

Step 1: Identify the facts

It is noted that the assertion states: 'Ethylene increases the yield in cucumber', and the reason states: 'Ethylene promotes female flower in cucumber'. First, it needs to be identified if these statements are scientifically correct.

Step 2: Research facts

After researching the facts, it is found that ethylene is indeed a plant hormone that can promote the growth of female flowers in cucumbers (as stated in the reasoning) and by doing so, it increases the yield of cucumbers (as stated in the assertion).

Step 3: Analyze the validity of the reason as an explanation

Since increasing female flowers means increasing potential fruit (since only female flowers produce fruit in cucumbers), and fruits are the yield in case of cucumbers, it is therefore correct to say that promoting female flowers in cucumber leads to an increased yield.

Key Concepts

Plant Hormones

Plant hormones are essential regulators in plant growth and development. They are chemical substances that significantly influence several aspects of plants’ life processes. Among the various types of plant hormones, ethylene is well known for its role in numerous plant responses. Ethylene is a gaseous hormone that plays a critical role in:

• Fruit ripening
• Leaf fall
• Flower opening

Ethylene is unique because it can diffuse through the air, contributing to its effects even at low concentrations. It interacts with other hormones, such as auxins, to modulate growth and developmental processes. Its ability to regulate the development of flowers is particularly relevant in the context of enhancing agricultural productivity.

Cucumber Yield

Cucumber yield refers to the amount of cucumbers produced by a plant. This is an essential factor for farmers and gardeners as it dictates how plentiful the harvest will be. Yield is influenced by various factors, including:

• Plant genetics
• Environmental conditions
• Soil quality
• Water availability
• Nutrient supply

Ethylene plays a significant part in this as it encourages the development of more female flowers which directly correlates to higher fruit production. The management of these factors can lead to a substantial improvement in the quantity of cucumbers produced.

Female Flower Promotion

In cucumbers, the differentiation between male and female flowers is crucial. Female flowers are the ones that develop into fruits. Ethylene promotes female flower production by influencing the hormonal balance within the plant. This hormone affects the expression of certain genes, steering the plant toward forming more female blossoms instead of male ones.
This is especially beneficial in cucumbers where the number of female flowers directly impacts the potential fruit yield. By enhancing female flower production, growers can effectively increase the yield of their crops, making ethylene a beneficial tool in agricultural practices.

Fruit Production in Plants

Fruit production is a vital aspect of a plant’s reproductive process. It involves complex stages from flower initiation to fruit set and maturation. In cucumbers, fruit production relies on the successful fertilization of female flowers. Scheduled and properly managed ethylene applications can enhance this process, as more female flowers typically mean more fruits.
The process can be broken down into stages:

• Flower initiation
• Pollination and fertilization
• Fruit development
• Fruit maturity and ripening

Controlling factors such as ethylene levels allows farmers to optimize the yield by maximizing fruit production. Understanding these stages helps in effectively harnessing the potential of plant hormones like ethylene to support and increase fruiting in cucumber crops.