Question

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Enlist the general characters of Angiosperms with two examples.
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Answer 1

Answer -

$\bf{ General \:characteristics \:of \:\:Angiosperms :}$

• Angiosperms is made up of two words :- angeion - vessel; sperma - seeds.

• The seeds of angiosperms are enclosed by fruit wall or pericarp.

• Double fertilization is present in angiosperms.

• In angiosperms, fertilization is occurs by pollen tube formation called siphonogamy.

• Xylem vessels are present only in angiosperms.

• Endosperm is triploid in angiosperms .

• There are 250k+ species of angiosperms.

• Angiosperms are the most abundant plants.

• $\bf{ Examples :}$ Cactus, mango, roses, onion, ficus religiosa (peepal), Nerium (kaner).

Angiosperms are divided into two classes -

1. $\bf{ Dicotyledons :}$

• They have two cotyledons.
• Pea and gram are the examples of Dicotyledons.

2. $\bf{ Monocotyledons :}$

• They have one cotyledons.
• wheat and rice are the examples of monocotyledons.

Answer 2

$\huge \red{\sf{ Answer :}}$

$\bigstar \: \underline{\purple{\sf General \: characteristics \: of \: Angiosperms:}}$

(i.) Habitat: The Angiosperms are group of highly evolved plants, primarily adapted to terrestrial habitat.

(ii.) Alternation of generations: Angiosperms show heteromorphic alternation of generations in which the sporophyte is diploid dominant, autotrophic and independent, while the gametophytes are recessive, haploid and dependent on the sporophyte.

(iii) Body: The body of sporophyte is divisible into root, stem and leaves. It has flowers, fruits and seeds.

(iv.) Vascular tissues: Vascular tissues are well differentiated. Xylem shows vessels or tracheae, while phloem has sieve tubes and companion cells.

(v.) Spore: Heterospory is exhibited by all Angiosperms. Microspores (also called pollens) are formed in microsporangia. They develop on highly specialized microsporophylls or stamens, while megaspores are formed in megasporangia (or ovules) borne on highly specialized megasporophylls called carpels.

(vi.) Sporophylls: Besides the essential whorls of microsporophylls (Androecium) and megasporophylls (Gynoecium), there are accessory whorls of sepals (calyx) and petals (corolla), clustered together into flowers.

(vii.) Pollination: The pollination is indirect and maybe self or cross.

(viii.) Sexual reproduction:

• There is typically double fertilization, one male gamete fusing with egg cell and another fusing with secondary nucleus.
• The zygote continues to develop within the ovule until seed is developed. The ovary simultaneously ripens into a fruit.

$\red{\bf e.g.\: Helianthus\: annus,\: Zea \:mays.}$