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Chapter 2, Lesson 1, Reproduction Survival depends on reproduction. Sexual Reproduction: a new organism from 2 parents Fertilization: male sperm joins female egg to create new life New organism gets genetic material from both parents Promotes variety in species….species can improve over time and be more well suited Asexual Reproduction: a new organism from a single parent Offspring are identical to single parent Eliminates need of a mate Types of Asexual Reproduction Splitting: genetic material is copied and cell splits into 2 exact copies (bacteria) Budding: small part of parent grows into a new complete organism (cnidarians, sponges, fungi) Vegetative Propagation: new plant from leaf, root, or stem (runners) Chapter 2, Lesson 2, Plant Life Cycles Mosses and Ferns Spores can develop into new plants without fertilization during asexual stage. New plant creates male and female structures. Water joins the 2 and fertilization occurs and a new plant is created. Flowers Flowers contain the reproductive organs of angiosperms Petals: bright, outer part; attract pollinators Sepals: below petals, offer protection during bud stage Stamen: male; filament & anther; produces pollen grains that contain sperm cells Pistil: female; stigma, style, & ovary; holds egg cells; where fertilization occurs Complete flower: contains all parts Incomplete flower: missing one or more parts Perfect flower: has both stamen and pistil (lilies, gladioli, tulips) Pollination: transfer of a yellow powder called pollen(male cells) from stamen to pistil Can be carried by bees, birds, animals, wind. (brighter plants are usually pollinated by animals) These cells then move down the style of pistil to ovary where fertilization occurs. Embryo is beginning of new offspring inside a seed. As seed grows, ovary enlarges and becomes fruit Seed contains: embryo (material for new plant), cotyledon (food supply), seed coat (protection) Seed moves to favorable location to germinate (become a new plant) Self-pollination occurs when perfect flowers have both parts and make connection Cross-pollination is when pollen from one plant pollinates a different plant Monocot: single food supply; parallel veins, petals in groups of 3 Dicot: 2 food supplies; branched veins, petals in groups of 4 or 5 Conifer: gymnosperm; seeds but no flowers (cones) Seeds are dispersed when cones are blown off and carried by wind. Animals also eat seeds and then carry them to another location. Chapter 2, Lesson 3, Animal Life Cycles Metamorphosis: series of distinct growth stages Complete Metamorphosis: 4 stages (butterfly) Egg Larva: immature stage; does not resemble adult Pupa: hard caselike cocoon; non feeding stage Adult Incomplete Metamorphosis:3 stages (grasshopper) Egg Nymph: similar to adult but smaller and lacks wings and sex organs Adult External Fertilization: egg and sperm are joined outside the female’s body Sex cells must stay moist to survive Amphibians and most fish release sex cells into the water. Chances of fertilization are decreased, so organisms release a large number of cells to overcome Internal Fertilization: egg and sperm are joined inside female’s body Increases chance of fertilization; protected from dangers outside Some organisms develop inside eggs, others inside the mother. Liquid inside egg is proper environment; yolk feeds the embryo Chapter 2, Lesson 4, Traits and Heredity Heredity: passing down of traits from parents to offspring Inherited Trait: trait received from parents (hair/eye color, dimples, facial features) Instinct: way of acting or behaving that an animal is born with (babies breathe, spiders spin webs) Learned Behavior: develops over time from practice Imprinting: social bond with another organism (ducks follow mom) Gregor Mendel: scientist who studied genetics and found the following Gene: contains chemical instructions for inherited traits on chromosomes inside nucleus Genes come from both parents Dominant Trait: stronger; masks the other Recessive Trait: one that is hidden Pedigree: chart used to trace history of physical traits in a family