Draw a schematic transverse section of a mature anther of an angiosperm. Label its epidermis, middle layers, tapetum, endothecium, sporogenous tissue and the connective.

An anther is a tetragonal structure consisting of four microsporangia located at the corners. Two microsporangia are located in each lobe of the anther. The microsporangia undergo development and become pollen sacs that contain microspores. The transverse section of an angiospermous anther and its parts has been shown below:

When and where do tapetum and synergids develop in flowering plants? Mention their function.

Tapetum is the innermost layer of the anther wall that develops during microsporogenesis in the anther. A typical anther consists of four microsporangia that are surrounded by anther wall. Anther wall consists of the outer epidermis, endothecium, middle layers and innermost tapetum. Its function is to provide nourishment to the developing pollen grains. Synergids develop during megasporogenesis in the ovule (megasporangium) inside the ovary. These are haploid cells that are located at the micropylar end of the embryo sac in the ovule. The embryo sac is formed from a single megaspore that undergoes three mitotic divisions to form 8 nucleated and seven celled structure. Among these, two are synergids. Synergids have the filiform apparatus which help to guide the pollen tube into it.

You are given castor and bean seeds. Which one of the two would you select to observe the endosperm?

Endosperm can be characterised as a tissue that stores food materials and provides nutrition to the developing embryo. This has been observed that in some plants, this tissue is completely absorbed before maturity. For example, pea, beans, etc. In a condition to choose between castor and bean seeds for the examination of the endosperm. The selection of castor seeds will be suitable as the endosperm will be present in those seeds.

Differentiate between Parthenocarpy and Parthenogenesis. Give one example of each.

Criteria Parthenocarpy Parthenogenesis Definition It is the production of fruit from the ovary without fertilization. It is the development of an unfertilized egg into a complete individual without fertilization. Criteria Parthenocarpy Parthenogenesis Occurrence It occurs because of unsuccessful pollination. It occurs only in plants. It occurs in both plants and animals. Criteria Parthenocarpy Parthenogenesis Product It produces seed-less fruits. For example, Banana, pineapple, watermelon, papaya, etc. It gives haploid organisms. For example, Some plants such as Datura, Nicotiana, etc., and animals like drones, Typhlina brahmina, etc.

E M B I B E

Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 32

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IMPORTANT

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What does the filiform apparatus do at the entrance into the ovule?

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Important Questions on Sexual Reproduction in Flowering Plants

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 35

When a seed of an orange is squeezed, many embryos, instead of one are observed. Explain how it is possible?

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 36

Are pollination and fertilisation necessary in apomixis? Give reasons.

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 37

Explain non-recurrent and recurrent apomixis.

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 38

Describe endosperm development in coconut.

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 39

Double fertilization is reported in plants of both castor and groundnut. However, the mature seeds of groundnut are non-albuminous and castor are albuminous. Explain the post-fertilization events that are responsible for it.

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 40

Why does endosperm development precede embryo development in angiosperm seeds? State the role of endosperm in mature albuminous seeds.

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Biology Crash Course (Based on Revised Syllabus-2023)>Chapter 1 - Sexual Reproduction in Flowering Plants>Exercise>Q 41

Plumule forms which organ during seed germination?

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