Question

2. Distinguish between the following pairs :
(a) Flower and inflorescence,
(b) Petals and petaloid sepals.
(c) Polyandraus and Polyadephous androecium
3. Where are the following structures/parts located and
what are their functions ?
(a) Placenta
(b) Thalamus
(c) Anther
(d) Stigma

Answer 1

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$\huge\red{\underline{{\bf Question : }}}$

1. Distinguish between the following pairs :

(a) Flower and inflorescence,

(b) Petals and petaloid sepals.

(c) Polyandraus and Polyadephous androecium.

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2. Where are the following structures/parts located and what are their functions ?

(a) Placenta

(b) Thalamus

(c) Anther

(d) Stigma

$\huge\red{\underline{{\bf Answer : }}}$

$\large{\boxed{{\bf\blue{Flower \: and \: inflorescence:-}}}}$

Flower :-

▪️The flower is a modified shoot which shows distinct nodes and internodes and the stalk of the flower is called pedicel

Inflorescence :-

▪️Inflorescence is a group of flowers arranged on a floral axis which does not show distinct nodes and internodes and the stalk of the flower is called peduncle.

$\large{\boxed{{\bf\pink{Petal \: and \: Petaloid:-}}}}$

Petal :-

▪️Petal is the part of the flower which is the non-essential whorls that are brightly colored to attract insects for pollination process.

Petaloid :-

▪️Petaloid is when the perianth is non-green i.e. when petals and sepals appear to be undifferentiated. Petaloid is resembling the petal of a flower.

Example, Michelia sps.

$\large{\boxed{{\bf\blue{Polyandraus \: and \: Polyadephous \: androecium:-}}}}$

▪️Polyandrous Androecium is when stamens

are many free e.g., Corchorus. Polyadelphous Androecium is when filaments are united in many groups with their anthers remaining free e.g., Ricinus, Citrus etc. Explanation: Androecium is the stamens of a flowering plant collectively.

$\large{\boxed{{\bf\green{Placenta}}}}$

▪️Funiculus in the part equivalent to the umbilical cord in which the ovules are attached inside a flower's ovary.

▪️The part of the ovary where funiculus is present is called the placenta.

▪️Its function is to provide a connection with the ovary walls and the flower and provide nutrients to the developing embryo.

$\large{\boxed{{\bf\red{Thalamus}}}}$

▪️The thalamus is a small structure within the brain located just above the brain stem between the cerebral cortex and the midbrain and has extensive nerve connections to both.

▪️The main function of the thalamus is to relay motor and sensory signals to the cerebral cortex.

$\large{\boxed{{\bf\green{Anther}}}}$

▪️The anther is a key structure in the reproduction of flowering plants.

▪️It sits atop the filament of the male structure known as the stamen.

▪️It produces the male sex cells, stores them, and provides a place for them to stay until the time is right for them to be dispersed.

$\large{\boxed{{\bf\red{Stigma}}}}$

▪️The stigma is composed of stigmatic papillae, the cells which are receptive to pollen.

▪️The stigma receives pollen and it is on the stigma that the pollen grain germinates.

▪️Often sticky, the stigma is adapted in various ways to catch and trap pollen with various hairs, flaps, or sculpturings

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