Earthworm-Morphology
Chapter Name : Structural Organization In Animals |
Sub Topic Code : 103_11_07_03_05 |
Topic Name : Earthworm-Morphology |
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Sub Topic Name : Reproductive System |
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Introduction
Earthworm is hermaphrodite (bisexual), i.e., testes and ovaries are present in the same individual.
Pre-Requisites:
To understand the reproductive system of an earthworm.
Activity:
Videos which show how reproduction in earthworm takes place.
Real Life Question:
How does fertilization in earthworm take place?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Testes | present in the 10th and 11th segments. Their vasa deferentia run up to the 18th segment where they join the prostatic duct. |
| Accessory glands | present one pair each in the 17th and 19th segments. |
| Ovaries | One pair of ovaries is attached at the inter-segmental septum of the 12th and 13th segments. Ovarian funnels are present beneath the ovaries which continue into oviduct. |
| Fertilisation and development | occurs within the cocoons which are deposited in soil. The ova (eggs) are fertilised by the sperm cells within the cocoon which then slips off the worm and is deposited in or on the soil. The cocoon holds the worm embryos. After about 3 weeks, each cocoon produces two to twenty baby worms |
Learning aids / Gadgets
| Gadgets | How it can be used |
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Practical examples around us
| Examples | Explainations |
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What you learn in Theory:
The different reproductive organs involved in earthworm reproduction.
What you learn in Practice:
How development of earthworm takes place.