4.6A
Patterns of Change: Metamorphosis
Science Reading Passage
4th Grade Life
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Expository Text:
Think about what a caterpillar looks like. Now think about a butterfly. Do the two look alike or different? They look very different, but both are parts of the life cycle of a butterfly. All living things change as they grow, but some young animals look very much like their parents while others do not. Insects such as the butterfly go through four stages of growth. The egg is the first stage of growth. Very often the butterfly will lay eggs on the underside of leaves. The larva is the second stage of growth. The larva is the insect when it hatches. A larva eats all of the time. Their first meal is the leaf on which the egg was laid. When the larva has eaten and grown larger, it stops eating and makes a hard covering for itself. The insect is now a pupa and is in the third stage of growth. The insect slowly changes when it is in the pupa. When the changes are completed the adult insect comes out. This is the fourth stage of growth. The adult insect looks like the adult that laid the eggs on the underside of the leaf. This four stage life cycle that an insect like a butterfly goes through is called complete metamorphosis. Other animals, like grasshoppers, go through a three stage life cycle. A three stage life cycle has an egg stage, a nymph stage, and an adult stage. The first stage is just like the four stage life cycle, an egg. But, when the egg hatches the animal in the second stage looks almost like a small adult. The animal is called a nymph. The nymph eats and grows until it sheds it outer skin a number of times and then develops into an adult. This three stage life cycle is called incomplete metamorphosis.
4.6A
Patterns of Change: Metamorphosis
Science Reading Passage (continued)
4th
Grade Life
Questions:
1. What is the main idea of this passage? A. Stages of an incomplete metamorphosis B. Stages in a complete metamorphosis C. How insects grow and change D. All living things go through patterns of change
Use the diagram below and your knowledge of science to answer questions 2 and 3.
2. What is missing in the box? A. Pupa B. Nymph C. Larva D. Grub
3. What process is pictured in the diagram? A. Complete metamorphosis B. Photosynthesis C. Respiration D. Incomplete metamorphosis