Chapter Menu Lesson 1: Sexual Reproduction and Meiosis Lesson 2: Plant Reproduction Lesson 3: Animal Reproduction Lesson 4: Asexual Reproduction Click on a hyperlink to view the corresponding lesson.

3.1 Sexual Reproduction and Meiosis egg sperm fertilization zygote meiosis diploid haploid

What is sexual reproduction? 3.1 Sexual Reproduction and Meiosis What is sexual reproduction? Reproduction in organisms produces new offspring. Sexual reproduction is the production of an offspring that results when the genetic materials from two different cells combine.

What is sexual reproduction? (cont.) 3.1 Sexual Reproduction and Meiosis What is sexual reproduction? (cont.) Half the genetic material in sexual reproduction is contained in: an egg cell a sperm cell In a process called fertilization, the sperm and egg cells fuse together forming a zygote. Meiosis and Fertilization

Advantages of Sexual Reproduction 3.1 Sexual Reproduction and Meiosis Advantages of Sexual Reproduction Genetic variation Variety of genetic traits in a population of the same species Can help a species survive changes in environmental conditions

Advantages of Sexual Reproduction (cont.) 3.1 Sexual Reproduction and Meiosis Advantages of Sexual Reproduction (cont.) Selective breeding Male and female organisms with certain preferred traits are selected to be the parents of offspring with those preferred traits Produces groups of organisms with similar traits Reduces genetic variation

Disadvantages of Sexual Reproduction 3.1 Sexual Reproduction and Meiosis Disadvantages of Sexual Reproduction Getting egg and sperm together for fertilization can be difficult Time is needed for organisms to grow and develop before they can reproduce

Why is meiosis important? 3.1 Sexual Reproduction and Meiosis Why is meiosis important? Meiosis is cell division that produces sperm or eggs from certain reproductive cells in an organism. Meiosis ensures that a species’ offspring inherit the correct chromosome number. Without meiosis, the chromosome number would double with each generation.

Maintaining Diploid Cells 3.1 Sexual Reproduction and Meiosis Maintaining Diploid Cells A diploid cell in an organism contains pairs of homologous chromosomes that equal the chromosome number of that organism’s species. A diploid human cell has 23 pairs of homologous chromosomes. Homologous chromosomes are similar, but not identical.

Creating Haploid Cells 3.1 Sexual Reproduction and Meiosis Creating Haploid Cells A haploid cell contains one chromosome from each homologous pair.

Creating Haploid Cells (cont.) 3.1 Sexual Reproduction and Meiosis Creating Haploid Cells (cont.)

3.1 Sexual Reproduction and Meiosis Phases of Meiosis I Prophase I—Nuclear membrane breaks apart and chromosomes condense. Metaphase I—Sister chromatids line up along the center of the cell. Cytoskeleton fibers attach to sister chromatids.

Phases of Meiosis I (cont.) 3.1 Sexual Reproduction and Meiosis Phases of Meiosis I (cont.) Anaphase I—Sister chromatids move to opposite ends of the cell. Telophase I—Nuclear membrane forms around each set of sister chromatids and the cytoplasm divides, forming two daughter cells.

Phases of Meiosis II Prophase II—Nuclear membrane breaks apart. 3.1 Sexual Reproduction and Meiosis Phases of Meiosis II Prophase II—Nuclear membrane breaks apart. Metaphase II—Chromosomes line up along the center of the cell.

Phases of Meiosis II (cont.) 3.1 Sexual Reproduction and Meiosis Phases of Meiosis II (cont.) Anaphase II—Sister chromatids of each chromosome begin to separate and move to opposite ends of the cells. Telophase II—A nuclear membrane forms around each set of chromatids, and the cytoplasm divides.

Comparison of Meiosis and Mitosis 3.1 Sexual Reproduction and Meiosis Comparison of Meiosis and Mitosis

What is the new cell that forms from fertilization called? A sperm 3.1 Sexual Reproduction and Meiosis A B C D What is the new cell that forms from fertilization called? A sperm B egg C haploid D zygote Lesson 1 Review

3.1 Sexual Reproduction and Meiosis B C D How many chromosomes from each homologous pair does a haploid cell contain? A one B two C three D four Lesson 1 Review

How many daughter cells are produced in meiosis? A one B two C three 3.1 Sexual Reproduction and Meiosis A B C D How many daughter cells are produced in meiosis? A one B two C three D four Lesson 1 Review

End of Lesson 1

3.2 Plant Reproduction spore pollen grain ovule seed angiosperm stamen anther filament pistil stigma style ovary pollen tube fruit

What is alternation of generations? 3.2 Plant Reproduction What is alternation of generations? Some organisms, including plants, have two life stages called generations. One generation has primarily diploid cells, the other generation has only haploid cells. Organisms that alternate between diploid and haploid generations have an alternation of generations.

What is alternation of generations? (cont.) 3.2 Plant Reproduction What is alternation of generations? (cont.)

How do seedless plants reproduce? 3.2 Plant Reproduction How do seedless plants reproduce? Seedless plants, such as mosses and ferns, grow from haploid spores, not seeds. Haploid spores that grow by mitosis and cell division into haploid plants. Fertilization results in a diploid zygote that grows by mitosis and cell division into the diploid generation. The diploid generation produces haploid spores by meiosis, and the cycle repeats.

How do seed plants reproduce? 3.2 Plant Reproduction How do seed plants reproduce? Most of the land plants that cover Earth grew from seeds—called seed plants. There are flowerless seed plants and flowering seed plants. The haploid generation is within diploid tissue. Separate diploid male and diploid female reproductive structures produce haploid sperm and haploid eggs.

The Role of Pollen Grains 3.2 Plant Reproduction The Role of Pollen Grains A pollen grain forms from tissue in a male reproductive structure of a seed plant. Pollination occurs when pollen grains land on a female reproductive structure of a plant of the same species.

The Role of Ovules and Seeds 3.2 Plant Reproduction The Role of Ovules and Seeds The female reproductive structure of a seed plant contains one or more ovules. After fertilization, a seed develops from the ovule.

Flowerless Seed Plant Reproduction In flowerless seed plants—gymnosperms— the seeds are not surrounded by a fruit. Cones are the male and female reproductive structures of conifers. Male cones produce pollen grains. Female cones produce eggs. Seeds form as part of the female cone.

Flowering Seed Plant Reproduction Flowering seed plants—angiosperms—include most of the plants you see. Fruits and vegetables come from flowering seed plants. Seed Plants

Reproduction and the Flower 3.2 Plant Reproduction Reproduction and the Flower A typical flower has male and female reproductive organs surrounded by petals. The stamen is the male reproductive organ. Pollen grains form at the tip of the stamen, in the anther. The filament is a long stalk that supports the anther and connects it to the base of the flower.

Reproduction and the Flower (cont.) 3.2 Plant Reproduction Reproduction and the Flower (cont.) The female reproductive organ of a flower is the pistil. Pollen can land at the tip of the pistil on the stigma, which is at the top of a long tube called the style. At the base of the style is an ovary containing one or more ovules which eventually will contain a haploid egg.

Reproduction and the Flower (cont.) 3.2 Plant Reproduction Reproduction and the Flower (cont.)

3.2 Plant Reproduction An Angiosperm’s Cycle

Fruit and Seed Dispersal 3.2 Plant Reproduction Fruit and Seed Dispersal Fruits and seed are important sources of food for people and animals. Fruits and seeds can be dispersed by: Air currents Animals Water Gravity What is the life cycle of a simple plant?

3.2 Plant Reproduction A B C D In alternation of generations, the haploid structures of the diploid generation produces daughter cells called what? A zygotes B spores C pollen D seeds Lesson 2 Review

3.2 Plant Reproduction A B C D What is an immature diploid plant that develops from the zygote of a seed plant called? A embryo B seed C fruit D stigma Lesson 2 Review

What is another name for a flowering seed plant? A zygote B conifer 3.2 Plant Reproduction A B C D What is another name for a flowering seed plant? A zygote B conifer C gymnosperm D angiosperm Lesson 2 Review

End of Lesson 2

3.3 Animal Reproduction gonad testes ovary metamorphosis

Animal Reproductive Organs 3.3 Animal Reproduction Animal Reproductive Organs Gonads are specialized organs that produce sperm or eggs. Testes are male gonads that contain a network of coiled tubes in which sperm cells form. Ovaries are female gonads that produce egg cells.

Internal Fertilization 3.3 Animal Reproduction Internal Fertilization Internal fertilization happens inside the body of an organism. Internal fertilization ensures that an embryo is protected and nourished until it leaves the female’s body. Examples Earthworms, spiders, insects, reptiles, birds, and mammals

External Fertilization 3.3 Animal Reproduction External Fertilization External fertilization occurs in the environment, outside of an animal’s body. Most animals that reproduce using external fertilization do not care for the eggs or young. Examples Jellyfishes, clams, sea urchins, sea stars, many fish species, and amphibians

External Embryo Development 3.3 Animal Reproduction External Embryo Development Animals whose embryos develop outside the mother are usually protected inside an egg.

3.3 Animal Reproduction Metamorphosis A developmental process in which the form of the body changes as an animal grows from egg to adult

3.3 Animal Reproduction Internal Development The embryos of some animals, including most mammals, develop inside the mother. A tissue or organ transfers nourishment from the mother to the embryo. Other embryos—some snakes, insects, and fishes—develop in an egg with a yolk inside the mother.

3.3 Animal Reproduction Gestation Gestation is the length of time between fertilization and the birth of an animal. Gestation varies by species and usually relates to the size of the animal at birth—smaller animals have shorter gestation.

Where are sperm formed in male animals? A eggs B ovaries C testis 3.3 Animal Reproduction A B C D Where are sperm formed in male animals? A eggs B ovaries C testis D glands Lesson 3 Review

How is the embryo in an egg nourished? A the outer covering 3.3 Animal Reproduction A B C D How is the embryo in an egg nourished? A the outer covering B an organ transfers nourishment from the mother C fluid produced in glands near the testes D the yolk Lesson 3 Review

D internal development 3.3 Animal Reproduction A B C D What is the developmental process in which the form of the body changes as an animal grows from egg to adult? A metamorphosis B gestation C fertilization D internal development Lesson 3 Review

End of Lesson 3

3.4 Asexual Reproduction asexual reproduction fission budding regeneration cloning

3.4 Asexual Reproduction Asexual Reproduction The production of offspring by one parent without a sperm and an egg joining Results in offspring that are genetically identical to the parent organism

Advantages of Asexual Reproduction No time or energy expended finding a mate. Less time to produce offspring Parent and offspring are genetically identical—equally well-adapted to the same environmental conditions.

Disadvantages of Asexual Reproduction Lack of genetic variation. Harmful mutations in the cells of an organism will be passed to offspring

Types of Asexual Reproduction Prokaryotes reproduce asexually by cell division that does not involve mitosis. Eukaryotes reproduce asexually by mitosis and cell division.

3.4 Asexual Reproduction Fission Bacteria reproduce by a process called fission which produces two genetically identical cells very rapidly.

3.4 Asexual Reproduction Mitotic Cell Division Some single-celled eukaryotes reproduce by mitotic cell division—mitosis followed by cell division. Produces two identical cells. Each cell is an organism.

3.4 Asexual Reproduction Budding Asexual reproduction in which a new organism forms on the parent organism The new organism—a bud—forms by mitosis and cell division, and eventually separates from the parent Example Some single-cell (yeast) and multicellular eukaryotes (hydra)

3.4 Asexual Reproduction Plant Cuttings If you cut a green stem from a houseplant and put it in water, roots and leaves can grow, producing a new plant. Some plants propagate themselves asexually. Examples Strawberry plants and kalanchoe plants

3.4 Asexual Reproduction Animal Regeneration Some animals have cells that can change into other cell types. Regeneration is asexual reproduction that produces new animals from pieces of an animal’s body. Regeneration is sometimes used to describe growth that replaces a missing part of an animal.

3.4 Asexual Reproduction What is cloning? Cloning refers to a method of asexual reproduction developed by scientists and performed in laboratories. Cloning produces identical individuals from a cell or cells taken from a multicellular organism.

3.4 Asexual Reproduction Plant Cloning

3.4 Asexual Reproduction Animal Cloning The first animal to be successfully cloned was a sheep named Dolly, in 1996

3.4 Asexual Reproduction A B C D What type of asexual reproduction involves reproduction by cell division only? A fission B budding C regeneration D cloning Lesson 4 Review

A mitotic cell division B cloning C regeneration D budding 3.4 Asexual Reproduction A B C D What type of asexual reproduction involves a new organism forming on the parent organism? A mitotic cell division B cloning C regeneration D budding Lesson 4 Review

3.4 Asexual Reproduction A B C D What type of asexual reproduction involves producing a new animal from pieces of an animal’s body? A plant cuttings B cloning C regeneration D budding Lesson 4 Review

End of Lesson 4

Chapter Resources Menu Chapter Assessment California Standards Practice Concepts in Motion Image Bank Science Online Virtual Lab BrainPOP Click on a hyperlink to view the corresponding feature.

A B C D What is the name for the process of a sperm cell and an egg cell fusing together? A sexual reproduction B fertilization C meiosis D pollination Chapter Assessment 1

What is one advantage of sexual reproduction? B C D What is one advantage of sexual reproduction? A produces many offspring B offspring are genetically identical C offspring have more genetic variation D can produce offspring quickly Chapter Assessment 2

Where are pollen grains formed? A anther B ovule C testes D pollen tube Chapter Assessment 3

What are animal reproductive organs called? A zygotes B gonads C embryos D buds Chapter Assessment 4

What is not an advantage of asexual reproduction? B C D What is not an advantage of asexual reproduction? A organism does not have to spend time and energy finding a mate B can produce a number of offspring faster than with sexual reproduction C offspring have more genetic variation D parent and offspring are equally well adapted to the same environmental conditions Chapter Assessment 5

What type of organism can reproduce asexually by regeneration? SCI 2.a A B C D What type of organism can reproduce asexually by regeneration? A human B sea star C bacterium D yeast CA Standards Practice 1

What flower structure becomes fruit surrounding the seed? A stamen SCI 2.a A B C D What flower structure becomes fruit surrounding the seed? A stamen B pollen tube C ovary D pistel CA Standards Practice 2

A alternation of generations B asexual reproduction C metamorphosis SCI 2.a A B C D What term describes the development of a ladybug larva to an adult ladybug? A alternation of generations B asexual reproduction C metamorphosis D mitotic cell division CA Standards Practice 3

What type of seed plant does not produce flowers? A seedless plants SCI 2.a A B C D What type of seed plant does not produce flowers? A seedless plants B gymnosperms C angiosperms D strawberry plants CA Standards Practice 4

SCI 2.a A B C D How many times does division of the nucleus and cytokinesis happen in meiosis? A one B two C three D four CA Standards Practice 5

Meiosis and Fertilization Concepts in Motion 1

Concepts in Motion 2

Image Bank

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