Download Sculpt a Parasite

 Eww! What’s Eating You? Grades 1-­4 Sculpt a Parasite
Duration
50 minutes Group Arrangement
partners Setting
classroom Vocabulary
• Insects • Parasites • Habitat Materials • Salt dough
Description
Students will investigate similarities and differences in the characteristics of insects. Curriculum Expectations
Grade 1: Understanding Life Systems – Needs and Characteristics of Living Things Grade 2: Understanding Life Systems – Growth and Changes in Animals Grade 4: Understanding Life Systems – Habitats and Communities Safety First!
Listen carefully to the teacher’s instructions when carrying out activities. Background
Insects have six legs. The insect body has three distinct parts – the head, thorax and abdomen. The head contains the eyes and antennae; the thorax contains three pairs of legs and can contain one or two pairs of wings. Examples include butterflies, ants, bees, dragonflies, fleas, flies, termites and HEAD LOUSE!
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Unlike predators, parasites are generally much smaller than their host. Parasites show a high degree of specialization, and reproduce at a faster rate than their hosts. Classic examples of parasitism include interactions between human hosts and head louse. Head lice are wingless insects spending their entire life on human scalp and feeding exclusively on human blood. Head lice are grey in general, but their precise colour varies according to the environment sciencenorth.ca/schools Science North is an agency of the Government of Ontario
1 in which they were raised. After feeding, consumed blood causes the louse body to take on a reddish colour. Head One pair of antenna, each with five segments, protrudes from the insect's head. Head lice also have one pair of eyes. Head lice mouthparts are highly adapted for piercing skin and sucking blood. These mouthparts are retracted into the insect's head except during feeding. Thorax Six legs project from the fused segments of the thorax. These legs are short and terminate with a single claw and opposing "thumb". Between its claw and thumb, the louse grasps the hair of its host. With their short legs and large claws, lice are well adapted to clinging to the hair of their host. However, these adaptations leave them quite incapable of jumping, or even walking efficiently on flat surfaces. Lice can climb up strands of hair very quickly, allowing them to run and jump on to another host. Abdomen There are seven visible segments of the louse abdomen. The first six segments each have a pair of spiracles through which the insect breathes. Introduction 1. Discuss the distinct features insects have and the various habitats they occupy – even human heads! Activities Sculpt and Parasite • Have students build a head louse using salt dough (250 ml flour, 85 ml water, 85 ml salt and 15 ml vegetable oil). • Make sure students sculpt three distinct parts: a head, a thorax and an abdomen and the antennae, 6 legs (attached to the thorax but none to the abdomen) and compound eyes. Remember, head louse are wingless insects! Conclusion Discuss with students how lice travel from host to host. Lice have no wings or powerful legs for jumping, so they move by using their claw-­‐like legs to transfer from hair to hair. Normally head lice infest a new host only by close contact between individuals, making social contacts among children and parent-­‐child interactions more likely routes of infestation than shared combs, brushes, towels, clothing, beds or closets. Head-­‐to-­‐head contact is by far the most common route of lice transmission. sciencenorth.ca/schools 2