Mechanism of Excretion in Earthworm

In earthworm, water, urea and Co2 are major waste products. In earthworm nephridia is excretory organ.

Body fluid enters into nephridia through nephrostome. Nephridium continues into a coiled tubule which allows selective re-absorption of materials. At last waste products are excreted out through nephridiopore

Then you can tackle the strawberry, it does not have an unbearable shape for a beginner, but you can sketch it taking into account the effects of refraction of light, reflection and other moments of detail. Begin to portray living beings. This is much more difficult, but already a big breakthrough. For him, you will need to constantly observe how this or that pose looks, plus facial expressions and movements. Very useful knowledge will be – on anatomy., It is useful for creating sketches showing body position, facial expressions or gestures. A good exercise is to do as many sketches of body movements or facial expressions from life as possible in a few minutes. And practice.