Seed, Biology

Seed

A seed is a mature ovule enclosing an embryonic plant, stored food material (in endosperm, persistent nucellus or embryo itself) and a seed coat formed by one or two integuments. In h broad sense the term seed is also applied to small one-seeded, dry fruits (e.g., grains of wheat or barley which are in fact made up by fusion of fruit wall and seed coat) or other disseminules (fruits with attached bracts, inflorescences or even vegetative structures such as tubers and bulbils). The size, shape, color and surface of the seed show innumerable variations. Most orchids have minute seeds like dust particles.

Seeds of a majority of flowering plants are a few millimeters in diameter (e.g., mustard, guava and poppy) or extend to a length of about a centimeter (e.g., castor, cucumber and groundnut). Some tropical trees and lianas have fruits with very large seeds. The double coconut, Lodoicea maldivica has bilobed seeds as large as 10 cm weighing nearly 6 kg. The seed surface may be smooth, wrinkled, striated, ribbed, furrowed or it may have a variety of patterns on it. The surface may be glossy (as in linseed and castor), fleshy or pulpy (in Magnolia) or covered with hair (in cotton).

Posted Date: 1/23/2013 8:02:25 AM | Location : United States







Related Discussions:- Seed, Assignment Help, Ask Question on Seed, Get Answer, Expert's Help, Seed Discussions

Write discussion on Seed
Your posts are moderated
Related Questions
TYPES OF CELL WALL Cell wall differentiated into the following layers : 1. Primary Cell Wall       2. Secondary Cell wall             3. Tertiary Cell wall 1 .

Regeneration in Hydra You previously know that the Hydra has spectacular regenerative ability. The hydra is a small tubular, two layered fresh water animal computing 20mm in

Define Sweetness as a Function of Sugar? Sweetness is the most recognized functional property of sweeteners. Our preference for sweetness, regarded as innate, is apparent soon

Explain Beef Extract and Yeast Extract These are aqueous extracts of lean beef and brewer's yeast, respectively. Beef extract provides amino acids, peptides, nucleotides, organ

What is meant by the expression 'infant mortality'? Infant mortality refers to the number of babies in a population who die at the age of 1 year or less. It is usually express

Foods with moderate amounts of protein can be eaten in limited amounts. These foods include grains, bread, pasta, rice, potatoes, corn, and peas. Foods with little or no protein ar

Adverse Effects of Bronchospasm Nasal and throat discomfort can occur. Bronchospasm, sometimes severe, has been reported uncommonly in patients with reactive airway disease; za

Signify the term - Trachea Part of the respiratory system in insects, vertebrates and some spiders. In invertebrates it comprise tubules carrying air directly from outside to t

Q. What do you mean by Punch cards? Punch cards are used when the number of taxa to be keyed out is large. In this type of cards the holes at numbers corresponding to a charact

Neurological symptoms and signs occur in 30 to 40 per cent of patients with IE, are more frequent when IE is caused by S. aureus, and are associated with increased mortality rates.