Analyse the illustration given below and answer the following questions. (a) Identify the pigment labelled as ‘X’. (b) Which part of the plant produces this pigment? (c) How does ‘X’ induce flowering?
Official Solution
Correct Option:
(1)
Step 1: Understanding the diagram.
The diagram shows a pigment (X) converting into a signal which leads to flowering. This represents the concept of photoperiodism, where light-sensitive pigments control flowering in plants. Step 2: Identification of pigment ‘X’.
The pigment labelled ‘X’ is Phytochrome. It is a light-sensitive pigment that detects changes in light duration. Step 3: Site of production.
Phytochrome is produced in the leaves of the plant, which perceive light signals. Step 4: Mechanism of inducing flowering.
Phytochrome exists in two forms (active and inactive) and responds to light and dark periods. Based on day length, it triggers the production of a flowering hormone (florigen), which acts as a signal. Step 5: Final effect.
This signal (florigen) is transported to the shoot apex, where it induces flowering in the plant.
02
PYQ 2026
medium
biologyID: kerala-s
Which hormone maintains dormancy of seeds until favourable conditions?
1
Auxin
2
Gibberellin
3
Ethylene
4
Abscisic acid
Official Solution
Correct Option:
(4)
Step 1: Understand seed dormancy. Seed dormancy is a condition in which seeds do not germinate even under favourable conditions. It is an important mechanism that helps plants survive adverse environmental conditions. Step 2: Identify the hormone responsible. Abscisic acid (ABA) is known as a growth-inhibiting hormone. It plays a major role in inducing and maintaining seed dormancy by inhibiting germination. Step 3: Analyze other hormones.
(A) Auxin: Promotes cell elongation and growth.
(B) Gibberellin: Promotes seed germination and growth.
(C) Ethylene: Involved in fruit ripening.
(D) Abscisic acid: Correct. It inhibits growth and maintains dormancy.
Step 4: Conclusion. Therefore, the hormone responsible for maintaining seed dormancy is abscisic acid. Final Answer:} Abscisic acid.
About Plant Physiology - KERALA-SSLC-EXAM
Plant Physiology is a vital chapter for KERALA-SSLC-EXAM aspirants. Mastering the concepts covered in this chapter is essential for securing a top rank.
By rigorously practicing the previous year questions associated with this chapter, you can identify high-yield topics, understand the examiner's perspective, and boost your confidence during the actual exam.
Frequently Asked Questions
Why focus on Plant Physiology PYQs?
Analyzing PYQs for this specific chapter reveals the most frequently tested concepts and the typical complexity of questions, allowing you to tailor your study plan efficiently.
How to best use this analysis?
Review the topic breakdown to see which sub-topics within Plant Physiology carry the most weight. Then, tackle the questions iteratively to solidify your understanding.
