unit 2 Science 3 Study note

Created
    English
  1. Other
  2. 2 Grade
  3. AvatarBy Ngô Hồng
Best for asynchronous learning and homeworkAssign in student-paced mode
Best for live in-class or video conferencing lessonsStart teacher-led lesson
Preview as student
Worksheet Image

Name Lesson 1 Summary Use with pp. 39–43 Lesson 1: How are animals grouped? Vocabulary trait a body feature passed onto an animal from its parents vertebrate animal with a backbone What All Animals Need are amphibians. Many amphibians spend All animals need food, water, oxygen, and part of their lives in water and part on land. shelter to live. Animals can drink water or get Most young amphibians live in water and water from the foods they eat. All animals get their oxygen through their moist skin need oxygen, which is a gas in the air. Most and gills. As they grow, most amphibians animals that live on land have lungs to develop lungs to breathe. breathe in oxygen. Many animals that live Reptiles usually have dry, scaly skin. They in water have gills to breathe in oxygen. have lungs to breathe air. Snakes, lizards, Animals eat plants or other animals for food. and turtles are reptiles. Shelters protect animals from the weather Birds have bills and feathers. They do and other animals. Some animals build not have teeth. Birds breathe air through shelters. Others have their own hard shells as lungs. Wings and light bones help birds fly. homes and to protect them. Feathers help keep birds warm. Most mammals have hair to keep them Ways of Grouping Animals warm. Mammals breathe air through lungs Sometimes we group animals by where and feed milk to their babies. they live or how they act. We can also group Animals Without Backbones animals by how they look. A trait is a body feature that is passed onto an animal from Most animals do not have skeletons made its parents. Traits can also be things an of bone inside their bodies. These animals animal does. are called invertebrates. Sea jellies, worms, An animal might be placed in more than mollusks, and arthropods are the major kinds one group. For example, we can group of invertebrate animals. Many mollusks animals by what they eat. Snakes, hawks, have a soft body inside a hard outside shell. and owls eat mice. Hawks and owls are also Octopus, clams, and snails are mollusks. in a group of animals that can fly. Arthropods are the largest group of animals without backbones. Arthropods wear their Animals With Backbones skeletons outside their bodies. They have legs An animal with a backbone is called with joints. Spiders and crabs are arthropods. © Pearson Education, Inc. 3 a vertebrate. Cats, dogs, and birds are Shells and skeletons outside the body vertebrates. Fish and snakes are vertebrates would weigh too much on big animals. So too. Vertebrate animals can look different, animals without backbones cannot grow as but they all have backbones. large as vertebrates. There are five groups of vertebrates. Fish, Most sea jellies live in the ocean, while amphibians, reptiles, birds, and mammals worms live in the soil. A small area of soil are the five kinds of vertebrates. Fish spend can have several million roundworms. There their lives in water. Most fish have scales are more animals without backbones than and breathe through gills. Frogs and toads animals with backbones. 12 Chapter 2, Lesson 1 Summary Quick Study

Worksheet Image

Name Lesson 1 Checkpoint Use with pp. 39–43 Lesson 1 Checkpoint 1. What do all animals need? 2. Should reptiles and amphibians be grouped together? Explain your answer. 3. If a rattlesnake and a black widow spider both make poison, why are they put in different groups? 4. Explain why most invertebrates are small in size compared to most vertebrates. © Pearson Education, Inc. 3 Quick Study Chapter 2, Lesson 1 Checkpoint 13

Worksheet Image

Name Lesson 2 Summary Use with pp. 44–47 Lesson 2: How do animals grow and change? Vocabulary larva stage in an insect’s life after it hatches from the egg pupa stage in insect’s life after larva, when it is in a hard covering Life Cycles change many times as they grow. Other An animal’s life starts out as an egg. vertebrates, such as pandas or monkeys, do Sometimes the egg develops inside the not change much as they grow. mother who gives birth to a live baby. A Frog’s Life Cycle For other animals, the mother lays an Amphibians change very much as they egg outside her body. The young animal become adults. Did you know that a frog develops in the egg and hatches when it is acts more like a fish when it is very young? ready. Some baby animals look like their The frog completes all the stages of its life parents when they hatch or are born. But cycle in one summer. Frogs grow in different most animals have to grow before they ways. In colder places, frogs dig into the look like their parents. The stages of the mud during the winter and will not become life cycle are birth, growth, development, adult frogs until the spring or summer. reproduction, and death. The adult frog lays eggs in the water. A Butterfly’s Life Cycle Tadpoles hatch from the frog eggs. Tadpoles The butterfly’s life cycle begins in an egg. grow and live underwater. They use gills The egg is so tiny it is hard to see. to breathe. Then the tadpole grows and Next a caterpillar hatches from the changes. Its tail gets shorter. Its legs start to egg. The caterpillar is now a larva. The grow. The back legs grow first. It grows lungs caterpillar must eat a lot to survive. so that it can breathe air on land. Finally it As it grows, the caterpillar sheds its skin becomes an adult frog that lives on land. It and forms a hard cover around itself. This goes back to the water to lay eggs. cover is called a chrysalis. The larva’s body A Mammal’s Life Cycle changes inside the chrysalis. The larva is now Mammals do not change a lot as they a pupa. Its body changes a lot while it is a grow. Many mammals look like their parents pupa. It grows wings and legs with joints. It when they are born. Mammals grow as they begins to look like an adult butterfly. © Pearson Education, Inc. 3 get older. Most mammals develop inside their It breaks the chrysalis and crawls out. The mother’s body. When they are born, they are adult butterfly dries its wings and flies away given milk from their mother. They also have to look for a mate. The butterfly finds a mate hair or fur. and lays eggs. Finally its life cycle ends when Humans take a long time to become it dies. adults. But some mammals become adults in Some Vertebrate Life Cycles only a few weeks. For example, a baby rabbit The life cycles of vertebrates can be very leaves the nest when it is less than three different. Some vertebrates, such as frogs weeks old. It will be an adult at six months. 14 Chapter 2, Lesson 2 Summary Quick Study

Worksheet Image

Name Lesson 2 Checkpoint Use with pp. 44–47 Lesson 2 Checkpoint 1. What is the purpose of the pupa? 2. Sequence List the sequence of steps in a butterfly’s life cycle. Use the signal words first, next, then, and finally. 3. Before a frog can live on land, how must its body change? 4. How is a mammal’s life cycle different from a frog’s or butterfly’s life cycle? © Pearson Education, Inc. 3 Quick Study Chapter 2, Lesson 2 Checkpoint 15

Worksheet Image

Name Lesson 3 Summary Use with pp. 48–53 Lesson 3: How do adaptations help animals? Vocabulary adaptation trait that helps an animal meet its needs in the place it lives inherited adaptations passed on from parent to offspring migrate move to another place when the seasons change hibernate during cold winter months, to slow down body systems to save energy Adaptations quills can cut into an attacker’s skin. The A trait that helps an animal meet its needs hooks on the quills keep them attached to in the place it lives is an adaptation. The the attacker. webbed feet of a pelican are an adaptation. Behaviors That Help Animals They help the pelican swim and survive in Behaviors are things that you do. Many the water. Adaptations are inherited, or behaviors are inherited. For example, walking passed on, from parents to their young. Body and talking are inherited behaviors. Reading parts such as feet and bills are important and writing are not inherited behaviors. You inherited adaptations. Most animals have have to learn how to read and write. But your many adaptations to help them live. ability to learn these behaviors is inherited. Adaptations for Getting Food Instincts Animals have many special adaptations An instinct is a behavior that an animal for getting food. Prairie dogs and moles have can do when it is born. One instinct is to feet that are good for digging. Hawks and respond to hunger. Baby birds open their eagles have feet that can hold tightly on to mouths when they sense a parent with food their food. Animals may have special teeth to is near. Some animals have an instinct to help them eat. Many birds have bills to help move, or migrate, when the seasons change. catch and eat their food. Butterflies migrate thousands of miles in the Adaptations for Protection winter. This helps them survive the winter. The way an animal looks and acts can help Other animals have an instinct to hibernate it survive. Some animals protect themselves by in the winter. An animal’s body system slows looking dangerous. Other animals blend into down when it hibernates to save energy. the area around them so they are hard to see. Learning © Pearson Education, Inc. 3 Many animals climb, run, hop, jump, fly, or Animals learn some behaviors from their swim away from danger. parents and other animals. Chimpanzees Some animals use poison to protect can learn how to use tools to catch insects. themselves. Skunks and weasels spray a bad They don’t know how to use tools when odor at their enemies. Special body parts like they are born. They learn how to use tools shells, teeth, claws, hooves, beaks, or pointed by watching other chimpanzees. Young body parts can protect animals from danger. chimpanzees watch what their parents and The porcupine is covered in quills. The other adults eat. This is how they learn porcupine uses muscles to make the quills which foods are safe to eat. stand up when it is scared. Then it turns around and raises its tail. The porcupine’s 16 Chapter 2, Lesson 3 Summary Quick Study

Worksheet Image

Name Lesson 3 Checkpoint Use with pp. 48–53 Lesson 3 Checkpoint 1. Give two examples of adaptations and tell how they help the animal survive. 2. What are some ways that animals protect themselves from their enemies? 3. Sequence List in the correct sequence what happens when a predator attacks a porcupine. Be sure to use the signal words first, next, and finally in your list of steps. 4. Name two types of adaptations having to do with an animal’s actions. 5. Why do some animals migrate or hibernate? © Pearson Education, Inc. 3 Quick Study Chapter 2, Lesson 3 Checkpoint 17

Worksheet Image

Name Lesson 4 Summary Use with pp. 54–57 Lesson 4: How are animals from the past like today’s animals? Animals That Lived Long Ago How Animals Today Compare to Fossils are signs of past life. Usually, only Those of Long Ago the hard parts of animals become fossils. A Fossils can tell us how animals have fossil is usually not the actual bone, but a changed over time. Dinosaurs are extinct. rock in the shape of the bone. An extinct animal no longer lives on Earth. After an animal dies, its remains become But some animals today look like animals covered with soft earth. The remains wear of long ago. away. This leaves a mold, or space, in the Fossils also tell us how Earth has earth. Over time, the mold fills with rock. changed over time. The drawing on pages The rock has the shape of the animal. This 56–57 of your textbook shows the Badlands is called a fossil mold. of South Dakota more than 65 million years ago. At that time, dinosaurs like Ancient Insects Tyrannosaurus Rex lived there. Plant fossils Small animals or parts of animals have were found in this area. These plant fossils been found in amber. Amber is hardened show that the climate was hot and wet. tree sap. Long ago, an insect got trapped That is why you see plants in the drawing in the sticky sap. Soon the sap covered the of the T. rex. insect. In time, the sap turned into the hard Over time, the place where the T. rex yellow or reddish-brown substance called lived became hot and dry. The picture on amber. You can see the animal’s body pages 56–57 also shows what the Badlands covering through the amber. It is millions look like today. The Badlands are almost of years old. like a desert. Only animals that can live in We find another type of fossil in tar pits. hot, dry conditions live there now. Thousands of years ago, saber-toothed tigers and other extinct animals fell into these oily pools. The soft parts of their bodies broke down. Only the bones remained. These fossils are the actual bones of these animals. © Pearson Education, Inc. 3 18 Chapter 2, Lesson 4 Summary Quick Study

Worksheet Image

Name Lesson 4 Checkpoint Use with pp. 54–57 Lesson 4 Checkpoint 1. What are some ways that fossils form? 2. Describe four kinds of fossils. 3. What can fossils tell us about extinct animals? © Pearson Education, Inc. 3 Quick Study Chapter 2, Lesson 4 Checkpoint 19