Question

define different types of placentation in plants?

Answer 1

Marginal placentation: It is seen in the pea seed. The placentation occurs as a ventral suture of the ovary. Ovules are arranged in two rows along the margins of the ovary. Axile placentation: It is seen in tomato seed. Placenta is axial and the ovules are formed at the angles where the septa join the central placenta. Ovules placed along the central axis of the ovary. Parietal placentation: It is seen in mustard seed. In this type of placentation, the ovules develop on the periphery of the ovary. Ovary has a single chamber but appears to be double-chambered because of the formation of a false septum. Basal placentation: It is seen sunflower. There occurs one ovule attached at the base. Free central placentation: It is seen in primrose. Ovules lie on the central axis. Superficial placentation: It is seen in nymphea. Ovules are almost attached entirely to the inner surface of the ovary.

Answer 2

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$\Huge{\mathfrak{\purple{\underline{ANSWER}}}}$

✓ Marginal placentation

• The ovary in which the placenta forms a ridge along the ventral suture of the ovary and the ovules develop on two separate rows is known to have marginal placentation.

• This type of placentation is found in peas.

✓ Free central placentation

• In free central placentation, the ovules develop on the central axis while the septa are absent.

• This type of placentation is found inDianthus and primrose.

✓ Basal placentation

• The ovary in which the placenta develops from its base and a single ovule is found attached to the base is said to have basal placentation.

• It is found in marigold and sunflower.

✓Parietal placentation

• When the ovules develop on the inner walls of the ovary, the ovary is said to have parietal placentation.

✓ Axile placentation

• In axile placentation, the placenta is axial and ovules are attached to it.

• Examples include China rose, lemon, and tomato.

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Thanks!!