Chapter 2. Lesson 2, Traits and Heredity Lesson 3, Animal Adaptations for Survival

Transcription

1 Chapter 2 Lesson 2, Traits and Heredity Lesson 3, Animal Adaptations for Survival

2 Vocab Spiral: pages Lesson 2 Vocabulary Words 1. heredity- the passing down of inherited traits from one generation to the next 2. inherited trait- a characteristic that is passed from parent to offspring

3 Lesson 2 Vocabulary 3. instinct- a way of acting or behaving that an animal is born with and does not have to learn 4. gene- a potion of a chromosome that contains chemical instructions for inherited traits 5. dominant trait- the form of an inherited trait that masks the other form of the same trait

4 6. recessive trait- the form of a trait that is hidden, or masked, in the hybrid generation 7. pedigree- a chart used to trace the history of traits in the family 8. carrier- an individual who has inherited a factor for a trait but does not show the trait physically

5 Explore on pg 99 upurpose: What are some inherited human traits? uhypothesis: Do you have any of the same traits as your classmates? umaterials: paper and pencil uprocedures: Check out page 99. uobservations: Record the data. See the next slide for an example chart. uconclusions: After completing a class chart on the boar, which form of each trait appears more frequently? Are some forms of traits more common than others? If so, why?

6 Thumbs Earlobe Tongue regular- hitchhiker- attached- unattached- non-rolledrolled-

7 Alternate Explore WS Purpose: Which trait occurs more often? Hypothesis: Assume that red blocks represent a dominant trait and green blocks represent a recessive trait. Which trait do you think occurs more often? Materials: brown lunch bag, 15 red blocks, 5 green blocks Procedure: Refer to the part of the WS under Test Your Prediction. Observations: Record your results for numbers 1-3. Conclusion: This goes with numbers 4 and 5.

8 pages Lesson 2, Traits and Heredity Create the Foldable on page 105. Heredity Dominant and Recessive Carriers and Pedigrees

9 What is heredity? Heredity is the passing down of traits from parents to offspring. Heredity applies to all organisms and can affect appearance and behavior.

10 pages What is heredity? Let s review. What is a trait? A trait is a characteristic of a person. What is an inherited trait? An inherited trait is a trait that an offspring receives from its parents. What are some examples of inherited traits? hair color, eye color, skin color, shape/size of nose, body type, height, shape/size of hands, dimples, tongue rolling, double joints, attached/unattached earlobes, the way you laugh, and facial features

11 pages What is heredity? Can heredity affect an organism s behavior? Some behaviors such as instincts are inherited. An instinct is a way of acting or behaving that an animal is born with and does not have to learn. It is an involuntary response. It is something you do not have to think about. Can you think of any instincts? spider spinning a web, breathing, birds building nests

12 pages What is heredity? Are all traits inherited? Some traits are learned or are a result from an organism s interaction with the environment. Think about a scar. Can you inherit a scar? A learned behavior is developed during the course of an animal s lifetime. Think about a dog? What are some requests that you have taught your dog? Your dog did not inherit those abilities from its parents. Learning helps animals to survive by enabling them to respond better to changes. One type of learned behavior is imprinting. Imprinting occurs when an animal forms a bond with another organism shortly after birth.

13 How are traits inherited? Gregor Mendel was an Austrian monk who studied and discovered the basic principles of heredity. Mendel began experimenting with pea plants at his monastery. He crossed plants that had different traits and observed how those traits were passed on. Based on his results, Mendel determined that inherited traits are passed from parents to offspring during reproduction. Mendel believed that offspring receives one of two factors from each parent. Today those factors are called genes. pages A gene contains chemical instruction for inherited traits. Genes are found on cell structures called chromosomes which are located in the nucleus of the cell.

14 pages How are traits inherited? Mendel said that for every trait passed on there is a dominant and a recessive form. A dominant trait is one that dominates, or masks/hides, another form of that trait. A recessive trait is one that is hidden, or masked, by another form of that trait. Each form of the trait can be represented by letters. A capital letter is used for the dominant form of the trait. A lowercase letter is used for the recessive form of the trait. In the pea plants that Mendell studied, he said that plants with purple flowers or P are dominant and white flowers or p are recessive.

15 How are traits inherited? Inherited traits are passed from parents to offspring during reproduction. Dominant traits (shown on diagram with uppercase letters) tend to be expressed more frequently than recessive traits. Recessive traits (shown on diagram with lowercase letters) are masked, or hidden, by the more dominant forms. Parent Generation PP pp Generation 1 Pp Pp Pp Pp Generation 2 PP Pp Pp pp

16 pages How do we trace inherited traits? Some of the traits controlled by genes are easy to see, such as hair color. Some individuals carry a trait without showing evidence of that trait themselves. A carrier is any individual who has inherited the gene for a trait but does not show that trait physically. A pedigree is a chart used to trace the history of traits in a family. Parents and offspring are shown in a pedigree. Parent s Generation Mother Father Daughter Daughter Son Son Children s Generation Dimples (dominant trait) No Dimples (recessive trait) Notice the lines, shapes, and the shapes that are shaded.

17 1. Which is an inherited trait? a. the ability to play the piano b. eye color TCAP Prep c. learning to speak a different language d. a baby breathing 2. Which is a learned behavior? a. a bird building a nest b. a duck imprinting c. a spider building a web d. a baby breathing 3. Which statement is TRUE? a. a gene carries an inherited trait b. a trait produces a gene c. a trait can only be learned d. Children pass inherited traits to their parents.

18 4. Where do you get your genes from? a. only from your mother b. only from your father c. half from your mother and half from your father d. most from your mother and some from your father 5. Which trait would NOT be passed on through a living thing s genes? a. a hooked beak b. webbed feet c. brown scales d. a broken wing TCAP Prep 6. Which of the following traits is inherited? a. the ability to ride a bike c. a long beard b. eye color d. the ability to recite a poem

19 Vocab Spiral: Lesson 3 Vocabulary Words pages adaptation- any characteristic that helps an organism to survive in its environment 2. protective coloration- a type of camouflage in which the color of an animal blends in with its background, protecting the animal against predators 3. protective resemblance- a type of camouflage which the color and shape of an animal blends in with its background, protecting it against predators 4. mimicry- an adaptation in which an animal is protected against predators by its resemblance to another, unpleasant animal

20 pages Lesson 3, Animal Adaptations for Survival Create the foldable on page 119. Main Idea What I learned Sketches Adaptations Adaptations to climate Camouflage and Mimicry

21 What is adaptation? Adaptations are physical structures or behaviors that help an organism survive in its environment. puffer fish Over time, organisms with successful adaptations survive more frequently and are able to pass on their characteristics to their young.

22 What is adaptation? A physical adaptation is an adjustment to internal or external structures. What do you think that means? pages Some examples of physical adaptations are fur color, long limbs, strong jaws, an animal holding their breath under water, or using gills for underwater breathing. Other examples include reptiles having dry, scaly skin which is waterproof, reptiles laying eggs with soft, leathery shells, birds having hollow bones to reduce weight for flight, peacocks using bright colored or elegant plumes to get the attention of their mate. Mammals are animals with fur or hair. Marsupials are pouched mammals that give birth to partially developed offspring. Monotremes are mammals that lay eggs like a duck-billed platypus.

23 What are behavioral adaptations? pages Instinct is an inherited behavior, one that is not learned but is instead done automatically. An adjustment in an organism s behavior is a behavioral adaptation or an adaptive behavior.

24 Some of these behaviors help animals find food, and others help animals defend themselves. Examples of behavioral adaptations: wolves traveling in packs to hunt large prey fish swimming in schools to help protect them from predators nocturnal animals come out only at night to search for food reptiles stay warm by sunning themselves because they are cold-blooded like amphibians and most fish birds and mammals are warm blooded; they can keep their body temperatures steady some birds and mammals perform elaborate, attentiongetting dances to get the attention of their mate mothers taking care of their young Don t forget about an instinct. It is an inherited behavior that is not learned but instead done automatically. What are behavioral adaptations? pages

25 What are adaptations to climate? Living things thrive in all areas of the world, including deserts and the frozen areas near Earth s poles. Examples of adaptations to climate: pages the dessert animal, fennec, a kind of fox that has large ears to provide a large surface to let heat escape humps of camels are made of fat which they can live off of when food is scarce in colder climates, animals are insulated by a thick layer of body fat called blubber or a heavy coat of fur birds have an air-trapping layer of soft, thick down feathers some behavioral adaptations such as penguins huddling together other animals migrate or move from one place to another animals such as bats, snakes, turtles, and frogs hibernate or spend a period of time of inactivity during cold weather

26 What are adaptations to climate? pages In very hot climates, animals must be able to get rid of excess heat. In colder climates, animals must reduce heat loss.

27 pages What adaptations do predators and prey have? Many adaptations develop because of predator and prey relationships. How Prey Escape to defend themselves, a pill bug will curl into a tight ball skunks spray a bad-smelling liquid some snakes and lizards have poison glands gazelles can run up to 49.7 mph opossums and hognosed snakes pretend to be dead How Predators Catch Prey for hunting at night, owls have excellent hearing, large eyes, large muscular wings, large talons or claws giant anteaters use their spine and sticky saliva covered tongues to pick up ants some woodpecker finches use a twig or cactus spine to remove insects from within trees

28 page 117 What adaptations do predators and prey have? Camouflage Any coloring, shape, or pattern that allows an organism to blend in with its environment is camouflage. Protective coloration is a type of camouflage in which the color of an animal helps it blend in with its background. In winter the artic fox has a white coat that blends in with the snow. In summer the fox s coat changes color to help it blend in with the plants that grow in the warm weather. Protective resemblance is the matching of color, shape, and texture to the environment. The walking stick insect, resembles a stick or a small branch.

29 What adaptations do predators and prey have? streamlined bodies in water environments camouflage Protective coloration helps arctic hares blend in with their snowy environment

30 What is mimicry? Mimicry is an adaptation in which an animal is protected from predators because it looks like a dangerous or unpleasant animal. How can the predators deceive their prey?

31 TCAP Prep 1. Which adaptation would you expect to find in marine mammals that live in extremely cold environment? a. large ears b. thin fur coat c. thick layer of blubber d. down feathers 2. How do animals get adaptations? a. they learn them from watching their parents b. they are born with them c. they get them when their environment changes d. they decide to get them when they need them

32 TCAP Prep 3. Which animal is MOST LIKELY to share an environment with a bear with white fur? a. a bear with brown fur b. a deer with red fur c. a rabbit with brown fur d. a fox with white fur 4. Which of the following is an adaptation to life under water? a. lungs b. gills c. light bones d. webbed feet

33 TCAP Prep 5. Which one is a trait that helps walking sticks thrive in wooded habitats? a. wing span b. body color c. diet d. flying speed