Unit 3 Lesson 4 How Do Animals Reproduce
- Slides: 18
Unit 3 Lesson 4 How Do Animals Reproduce? Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Life in Full Circle • Fish lay eggs. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Life in Full Circle • birds lay the eggs. • Bird parents protect the eggs until they have hatched. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Bringing Up Baby • Some animals, such as turtles, are on their own as soon as they hatch from their eggs. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Bringing Up Baby Other animals, such as penguins, give their young a great deal of care. • Penguins keep their young warm and fed until they are strong enough to take care of themselves. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Bringing Up Baby • Animals such as deer, bears, rabbits, cats, and kangaroos take care of their young by feeding them milk. • These animals care for their young for months or years until the young can live on their own. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Growing Up Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? Growing Up • Just like other animals, humans go through stages of development. It takes many years for a human baby to grow into an adult. • After a human egg is fertilized, it grows inside the mother. After nine months, the baby is born. • When babies are born, they have no teeth. They are not able to walk on their own. • Babies grow into toddlers. Toddlers learn how to walk and how to speak. Copyright © Houghton Mifflin Harcourt Publishing Company
Insect Life Cycles • Most insects undergo metamorphosis as they develop into adults. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? My, How You’ve Changed! • In complete metamorphosis, an animal goes through four different stages in its life cycle. • An egg hatches into a larva. • A larva develops into a pupa. • A pupa develops into an adult. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? My, How You’ve Changed! • A butterfly goes through complete metamorphosis. • The larva of a butterlfy is called a caterpillar. • The caterpillar grows into a pupa. • Inside a chrysalis, the pupa becomes an adult butterfly. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? My, How You’ve Changed! • What are the stages in a butterfly’s life cycle? Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? My, How You’ve Changed! • Some insects, such as dragonfiles and termites, go through a different series of changes. • In incomplete metamorphosis, an animal goes through three different stages in its life cycle. • First, the animal hatches from an egg as a nymph. • Nymphs look like tiny adults without wings. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? My, How You’ve Changed! • As the nymph grows larger, it molts. • Molting happens when an insect sheds its hard outer skeleton. • After several moltings, the insect, which now has wings, reaches its adult stage. Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Animals Reproduce? My, How You’ve Changed! • What are the stages in the life cycle of a grasshopper? Copyright © Houghton Mifflin Harcourt Publishing Company