1. Large: 2

Small: 3

2. Three

3. Four

4. No. Forewings hard and leathery, rear wings soft/delicate and can be opened out to form a large surface area

5. Like plastic, hard

6. Feelers

7. No. There are spiracles on each segment of the abdomen.

8. Yes. Mouth parts are located at the bottom of the head. Cutting edges and feelers.

9. 6 legs.

10. No. The rear legs are stronger.

11. No. The females and males differ. The female locust has an ovipositor and the male has a copulatory organ.

12. Protection: hard external skeleton, but it can use the feelers for feeling. Does not lose moisture, can cope without water. Can move around easily: walks, sometimes flies of jumps. Can look for food because of its locomotive ability, can see, has good mouth parts.

13. The learner should draw from life. If possible, a real creature must be observed.

14. Life cycle: adult, eggs, larva, pupa

Assignment 3:

The grasshopper belongs to the largest group in the animal kingdom, namely the insects.

What do you already know about this group?

Investigation: Catch a few different types of insects and bring them to class. Form groups of two or three and study the insect in the group of which the body parts can be distinguished easily. A grasshopper or a cricket works well. Answer the following questions (try your best to give a good answer so that you can get a good mark):

1. An insect has large as well as small eyes.

2. In how many main parts would you divide the body? _______________________

3. How many wings does the insect have? If the wings are folded against the

body, lift them up and look carefully. ______________________________________

4. Are all the wings the same? ___________________________________________

Describe. ____________________________________________________________

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5. What does the insect’s skin covering feel like?

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6. What does the insect feel with?

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7. Does the insect have a nose with which to breathe? Describe

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8. Does the insect have a mouth? Describe.

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9. How do you know that it is an insect that you are busy studying?

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10. Are all the legs developed equally strongly? _____________________________

What do you observe? __________________________________________________

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11. Do the tips of the abdomen look the same in all the insects of the same type? ___

Describe. ____________________________________________________________

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12. Insects are particularly well adapted to be able to survive under different circumstances. Describe (refer to protection, need of water, movement, ability to look for food).

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13. Make a drawing of the insect as seen from the side.

Build

Figure 1

• The body consists of three main parts: the head, the thorax and the abdomen.
• The insect has an exoskeleton that consists of a strong leathery material called chitin.
• The three pairs of articulated legs are attached to the thorax.
• Two pairs of wings are also attached to the thorax: the front ones are leathery and lie flat against the body; the hind ones are soft and fold underneath the front ones like fans.
• The head bears:

- two antennae (feelers) with which the insect feels;

- three small eyes that are called simple eyes;

- two large or compound eyes; and

- mouth parts.

• The abdomen has no attachments, except for small sexual organs at the tip that differ in the case of the male and the female.
• There is a small spiracle (breathing opening) on each segment of the abdomen.

Movement

Insects are very mobile. Just think about the agility of a fly and the distance that swarms of grasshoppers can fly.

The legs are articulated. The hind legs of the grasshopper are developed more strongly so that it can jump.

The front wings fold open diagonally and balance the insect during flight (like the wings of an aeroplane), while the soft hind wings fold open like fans and do the actual flying.

Figure 2

Feeding

The grasshopper is a herbivore with mouthparts that are very well adapted for this purpose. Amongst others, there are two small feelers with which it can feel the food so that it can push the food into its mouth. There are also two jaws with cutting edges that finely cut up the plant material. The grasshopper therefore has biting mouthparts.

Figure 3

Other insects have the same mouthparts as the grasshopper, although the shape can differ greatly to adapt to other ways of eating. For example, they can be licking (the fly), sucking (some moths) or biting (the mosquito).

Maintaining a water balance

The exoskeleton of the grasshopper forms a watertight skin covering. This means that the body does not lose moisture and therefore can survive in dry conditions. The plant material eaten by the grasshopper contains sufficient water.

Reproduction

In Grade 6 you learned that a fruit fly undergoes a complete change of form, or metamorphosis, from the time the egg hatches until an adult fly has developed. Can you still remember the stages? Fill them in on the illustration below.

Figure 4

The grasshopper does not undergo a complete metamorphosis. After the male and female have mated, the female lays eggs in the ground with her ovipositor. The small grasshoppers that hatch look just like the adults. They moult a few times as they grow. We therefore speak of incomplete metamorphosis.

Explain why the grasshopper and other insects are adapted to their environment particularly well.

Dependence on water:

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Obtaining food (distinguish between the grasshopper and other insects that undergo a complete metamorphosis).

Grasshopper:

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Insects that undergo complete metamorphosis:

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Respiration (Tip: why are insects not as dependent on a moist environment as the earthworm is?):

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Senses and communication (Tip: research whether grasshoppers can hear and make sounds)

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