EARTHWORM ( Annelids ) Flashcards Preview

Science GR 7 > EARTHWORM ( Annelids ) > Flashcards

Flashcards in EARTHWORM ( Annelids ) Deck (13):
1

Explain body structure (4)

  1. Long segmented body covered with fine bristles that are retractable
  2. 90-150 segments
  3. Front segment modified for mouth, last segment for anus
  4. longest earthworm in SA is 6.7 m

2

What is anterior and posterior? (2)

ANTERIOR - front

POSTERIOR - back

3

Explain the 2 ways the  EARTHWORM moves ?  (8)

1.  Circular muscles: that make up the segments are used to lengthen earthworms body

2.  Fine bristles that sticks out (protrude) from the front (anterior) segments anchors in soil while back (posterior) segments drag along. Then the bristles on the front (anterior) segments are pulled back and the bristles on the back (posterior) segments are anchored in the soil and push the front segments forward.

4

Explain how an EARTHWORMS eats and it's natural nutrition and how it has adapted? (6)

Front segment has membrane that covers mouth opening, helps to push food in mouth.

Earthworms naturally eats organic material:

plants, insect parts and bacteria 

But they have adapted for use of compost making by eating:

anything that once lived like leftover food, newspaper, eggshells, meat, tea bags

5

Explain EARTHWORMS respiration (4)

Through skin:

Oxygen dissolves on moist hide and absorbed through skin into the body tissue and transported to rest of body.

6

Discuss why Water Balance is important for EARTHWORMS (2)

Always moist to prevent drying out

Moisture on hide dissolves gases for respiration (breathing)

They HAVE TO live in moist enviroments

7

How does EARTHWORMS reproduce / multiply?

Earthworms are hermaphrodites

(both Male and Female)

The Clitellum (saddle like area) secreates slimy cocoon where eggs are fertilised during mating.

Clitellum is between 30 - 40 segment.

Juvenile (babies) hatch from cocoon

they look like earthworms

8

What is Hermaphrodites ?

Annimal with Male and Female organs

9

What is a Juvenile

Young animal - new born

10

What senses are very sensitive/best with the EARTHWORM?

Sense of TOUCH

Highly developed to feel even as a bird land close by.  They feel the vibrations in the ground and burrow deep into soil for protection.

11

What senses are the worst with EARTHWORMS?

SIGHT

EARTHWORMS can't see

12

What role does EARTHWORMS play in our ecosystem?

  • Decomposition of dead organic material
  • Kill harmful bacteria and makes healthy bacteria through their urine and faeces.
  • Responsible for healthy soil and plants
  • They help loosening the soil to let oxygen into the soil for plant growth.

13

EARTHWORM SKETCH

Q image thumb

A image thumb