How do living things reproduce?

Transcription

1 Lesson 1 Reproduction Lesson 2 Plant Life Cycles Lesson 3 Animal Life Cycles Lesson 4 Traits and Heredity How do living things reproduce?

2 sexual reproduction fertilization asexual reproduction vegetative propagation runner

3 What are sexual and asexual reproduction? Asexual reproduction is the production of a new organism from a single parent. Sexual reproduction is the production of a new organism from two parents.

4 How do organisms reproduce asexually? Organisms reproduce asexually by splitting, budding, vegetative propagation, and the development of eggs into new animals without fertilization.

5 How do sexual and asexual reproduction compare? Asexual reproduction requires only one parent, and offspring are identical to the parent organism. Sexual reproduction requires two parents, and offspring have a combination of traits from both parents.

6 Main Idea How do sexual and asexual reproduction differ? Sexual reproduction requires the sex cells of two parents to combine. The offspring shows traits from both parents. In asexual reproduction there is only one parent.

7 Vocabulary Vegetative propagation is asexual reproduction in the plant that produces new plants from leaves, roots, or stems. Runners are plant stems that lie on or under the ground and sprout up as new plants. A sperm cell from a male and an egg cell from a female join into a single unit in a process called. Sexual reproduction is the production of a new organism from two parents. Asexual reproduction is the production of a new organism from a single parent. asexual sexual vegetative reproduction fertilization runners reproduction propagation

8 Sequence What happens after a bud forms on an organism? small bud grows on parent bud may break off bud grows apart or attached to parent End of Lesson

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14 pollination pollen embryo seed coat germination monocot dicot conifer

15 What are seedless plant life cycles? spore case spores sperm new moss plant adult plant fern frond Fern Life Cycle spores heart shaped plant fertilized egg egg Moss Life Cycle fertilized egg new fern plant sperm egg

16 What are the parts of a flower? perfect/complete flower stigma filament anther perfect/incomplete flower style pistil egg stamen petal ovary imperfect/incomplete flower (male) sepal imperfect/incomplete flower (female)

17 What is the angiosperm life cycle? adult plant seedling stamen pollinator ovary seed and fruit pistil

18 What is in a seed? A seed has three main parts: the embryo, the cotyledon (food supply), and the seed coat.

19 What is the conifer life cycle? male cones adult plant fertilized cones female cones pine seeds seedling

20 Main Idea What three features help make angiosperms the most plentiful plant group? flowers, seeds, and fruits

21 Vocabulary Germination is the development of a seed into a new plant. A produces seeds with a single cotyledon. A seed is surrounded by a tough outer coating called a. A produces seeds with two cotyledons. dicot germination monocot seed coat

22 Vocabulary Pollination is the transfer of pollen from the stamen to the pistil. Pollen is a yellow powder that contains sperm cells. An is the beginning of a new offspring. A is a gymnosperm, a plant that has seeds but not flowers. conifer embryo pollen pollination

23 Summarize What effect does water have in the moss life cycle? water carries sperm to female fertilization takes place End of Lesson

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32 metamorphosis complete metamorphosis larva pupa incomplete metamorphosis nymph external fertilization internal fertilization

33 What are animal life cycles? Many animals begin life looking like smaller versions of adults. Incomplete Complete Metamorphosis Grasshopper Butterfly adult eggs eggs larva nymph pupa adult Some Other animals animals go go through through four three distinct gradual stages of stages development in incomplete in complete metamorphosis. metamorphosis.

34 How does fertilization occur in animals? When a sperm cell combines with an egg cell, the resulting fertilized egg starts growing. External fertilization occurs when sperm and egg join outside of an animal s body. Internal fertilization is the joining of sperm and egg inside a female s body.

35 What happens to a fertilized egg? After fertilization, an embryo begins to develop inside an egg. In mammals, the embryo is fed by the mother s body as it develops. frog eggs In reptile and bird eggs, the yolk inside the egg provides the embryo with food. crocodile egg chicken egg

36 Main Idea Why do most aquatic animals use external fertilization and most land animals use internal? Aquatic animals can release their sex cells into the water because they will not dry out there. Land animals use internal fertilization to protect the sex cells from drying out.

37 Vocabulary The out-of-body joining of egg and sperm is called. A is similar to an adult form, but it is smaller and lacks wings and reproductive structures. The is a non-feeding stage during which a hard, caselike cocoon surrounds the organism. During incomplete metamorphosis the animal goes through three stages that occur gradually. incomplete external fertilization metamorphosis nymph pupa

38 Vocabulary In complete metamorphosis the animal goes through four distinct stages. A in an immature stage that does not resemble the adult. Internal fertilization is the joining of sperm and egg cells inside a female s body. Metamorphosis is a series of distinct growth stages that are different from one another. complete internal metamorphosis fertilization larva metamorphosis

39 Compare and Contrast How do complete and incomplete metamorphosis compare? complete metamorphosis: four stages egg, larva, pupa, adult Both: metamorphosi s incomplete metamorphosis: three stages egg, nymph, adult End of Lesson

40 metamorphosis (met ə môr fə sis) A series of distinct growth stages that are different from one another. (p. 114)

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48 heredity inherited trait instinct gene dominant trait recessive trait pedigree carrier

49 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.

50 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. Parent Generation PP pp Generation 1 Pp Pp Pp Pp Generation 2 Recessive traits (shown on diagram with lowercase letters) are masked, or hidden, by the more dominant forms. PP Pp Pp pp

51 How do we trace inherited traits? A pedigree chart can be used to trace the history of traits in a family. Parent s Generation Dimples (dominant trait) No Dimples (recessive trait) Mother Father Daughter Daughter Son Children s Generation Son

52 Main Idea Why are offspring similar to parents, but not exactly like either one of them? Offspring inherit one set of genes from each parent, so they have a mixture of traits.

53 Vocabulary A contains chemical instructions for inherited traits. A is any individual who has inherited the gene for a trait, but does not show that trait physically. Heredity is the passing down of traits from parents to offspring. A is one that dominates, or masks, another form of that trait. carrier dominant trait gene heredity

54 Vocabulary A is a chart used to trace the history of traits in a family. An is a trait that an offspring receives from its parents. A is one that is hidden, or masked, by another form of the trait. An is a way of acting or behaving that an animal is born with and does not have to learn. inherited trait instinct pedigree recessive trait

55 Fact and Opinion A friend claims that with practice anyone can roll their tongue. Is this fact or opinion? Explain. Tongue rolling is an inherited trait controlled by genes. Tongue rolling gets easier with practice. End of Lesson

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