Sexual Reproduction in Flowering Plants

Questions and Answers

What is the main function of the tapetum in the microsporangium?

To facilitate the dehiscence of the anther

To protect the microspores from adverse conditions

To nourish the developing pollen grains (correct)

To provide structural support to the anther

Which layers surround a typical microsporangium?

Xylem, phloem, and cambium

Cuticle, epidermis, and endodermis

Epidermis, endothecium, middle layers, and tapetum (correct)

Parenchyma, collenchyma, and sclerenchyma

What structural feature distinguishes the anther of angiosperms?

It has a bilobed structure with two theca (correct)

It is a singular elongated structure

It lacks a longitudinal groove

It contains only one microsporangium

What type of division do cells in the sporogenous tissue undergo to form microspore tetrads?

Meiotic divisions Signup and view all the answers

Which statement correctly describes the appearance of a microsporangium in a transverse section?

It appears near circular in outline Signup and view all the answers

What is the primary purpose of the outer three wall layers of the microsporangium?

To provide protection and aid in dehiscence Signup and view all the answers

How many microsporangia are located in a typical angiosperm anther?

Four microsporangia Signup and view all the answers

What is the expected ploidy of cells in the microspore tetrad after meiotic division?

Haploid (n) Signup and view all the answers

Study Notes

Sexual Reproduction in Flowering Plants

Stamen Structure

A typical stamen consists of a filament (stalk) and an anther (bilobed structure).
The filament's proximal end attaches to the flower's thalamus or petal.
Variation in the number and length of stamens exists across different flower species.
Observing stamens under a dissecting microscope reveals diversity in size, shape, and anther attachment.

Anther Characteristics

Angiosperm anthers are bilobed with two thecae (dithecous) in each lobe.
A longitudinal groove often separates the thecae.
Anthers are typically tetragonal, containing four microsporangia located at their corners.
Each microsporangium develops into a pollen sac filled with pollen grains.

Microsporangium Structure

In transverse sections, microsporangia appear near circular and consist of four wall layers: epidermis, endothecium, middle layers, and tapetum.
The outer three layers protect the microsporangium and assist in the anther's dehiscence to release pollen.
The tapetum, the innermost layer, nourishes developing pollen grains with its dense cytoplasm and typically multinucleated cells.

Microsporogenesis Process

As the anther matures, sporogenous tissue, a compact mass of homogenous cells, occupies the center of each microsporangium.
The cells undergo meiotic divisions to form microspore tetrads, which are typically haploid (n).

Description

This quiz focuses on the structure of the stamen, including the filament and anther, as part of the sexual reproduction process in flowering plants. It explores variations in stamens across different species, enhancing your understanding of plant anatomy. Test your knowledge on pollen grains and microsporangia as well.