 Involves the fusion of egg cell (ovum) and sperm cell (sperm)  Union of gametes occurs in two ways ◦ internal fertilization– occurs inside the female body ◦ external fertilization– occurs outside the organisms body

 Internal fertilization ◦ In internal fertilization, sperm cells are deposited inside the female’s body where they meet an egg cell.

 External fertilization ◦ Sperm cell and an egg cell unite outside the bodies of the parents. ◦ As they develop outside of the female’s body, fertilized eggs are not protected from predators or weather, and many will not survive these environmental conditions.

1. Mosses: - external fertilization - water allows the egg and sperm cell to meet - reproduces both asexually and sexually

The Moss

Sexual Reproduction in Flowering Plants

 Internal fertilization occurs through Pollination  Pollination is the transfer of male gametes in structures called pollen from the male reproductive part of the plant to the female reproductive part of the plant.

Pollen Transport  Pollen can be transported by: Pollinators such: bees, other insects, wind, and water

Seeds After fertilization the seeds are protected in fruit or cones. Seeds contain the plant embryo.

Insects  In many insect the male deposits a package of sperm inside the female.  Insects often change a great deal in form between hatching an adulthood.

 This change in form is called Metamorphosis  Metamorphosis can be incomplete or complete

Three stages: egg, nymph, adult Example: Grasshopper Adult and nymph resemble each other Incomplete Metamorphosis

Four stages: egg, larva, pupa adult Example: Butterfly Adult and larva look completely different Complete Metamorphosis

Asexual vs Sexual Reproduction AsexualSexual 1 parent cell2 parent cells No gametes, cells divide 2 sex cells (egg, sperm) Little variation in offspring Greater variation in offspring Little energy required Energy required for mating Less parental careGreater parental care

Sexual Reproduction [complete the table below (page 194) ] AdvantagesDisadvantages Little energy required to find mate (external fertilization) More energy required to find a mate (internal fertilization) Greater number of offspring can re-populate and area after a disaster (external fertilization) Few offspring are produced, so if the number of predators increases the population will decline (internal fertilization) More protection to embryo and more protection given to offspring (internal fertilization) Gametes, embryos, offspring not protected and often preyed upon Great genetic diversity in offspring so species may survive new diseases or other threats to the population Some beneficial traits may not be passed on to offspring

Complete questions: 1, 3, 4, 5, 7, 8, 9,10, 13, 16, 17 on page 195