The colorless plastids in green plants that store starch is?

Appeared in: KPSC Staff Nurse - 2015

Explanation

Amyloplasts are a specific type of leucoplast, which are colorless plastids found in plant cells.
Their main function is the synthesis and storage of starch from glucose, a process crucial for the plant's energy reserves.
Starch is stored within these organelles in the form of amylopectin and amylose.
They are abundant in non-photosynthetic storage tissues like roots, tubers (e.g., potatoes), and seeds, which are major sources of carbohydrates in the human diet.

Option A: Elaioplasts are leucoplasts that are specialized for the synthesis and storage of fats and oils (lipids), not starch.
Option B: Aleuroneplasts are a type of proteinoplast. Their primary function is to store proteins, particularly in the aleurone layer of seeds, not starch.
Option D: Proteinoplasts are leucoplasts that contain crystalline bodies of protein and are involved in protein storage, not starch storage.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Functions of different types of plant plastids as background academic context rather than a clinical decision trigger.
Understanding that plants store energy as starch in amyloplasts is fundamental to human nutrition, as starches are a primary source of dietary carbohydrates.
This knowledge is essential for nurses when providing dietary counseling to patients, explaining the nutritional content of foods like potatoes, rice, and wheat.
What if? If a patient requires a low-carbohydrate diet (e.g., for managing diabetes or weight), the nurse can advise them to limit foods rich in starch, which originates from the amyloplasts of plants.

How to Approach the Question

First, identify the key terms in the question: 'colorless plastids' and 'store starch'.
Recognize that 'colorless plastids' refers to a category called leucoplasts.
The question then asks for the specific type of leucoplast that 'stores starch'.
Analyze the prefixes of the options. The prefix 'Amylo-' is related to starch (e.g., the enzyme amylase digests starch).
'Elaioplast' relates to oil, and 'Proteinoplast' clearly relates to protein.
Based on this word association and biological knowledge, conclude that Amyloplast is the plastid responsible for storing starch.

Concept Tested & Keywords

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E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) pp. 17-19, 249-251

Practise the full KPSC Staff Nurse - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.