Developing Zygote Seeds Eggs Embryos Developing Zygote When

Developing Zygote Seeds, Eggs, Embryos

Developing Zygote • When a sperm and egg fuse, a single-celled zygote is formed, • the zygote divides and develops into an embryo • Embryos are protected when they develop inside • seeds, • eggs, • mother

Seeds • A seed is a fertilized ripened ovule of a flowering plant • Three basic parts of a seed are the embryo, stored nutrients, and a seed coat. • Stored nutrients are in the form of either sugar or starch • Most of the world’s food comes from seeds of three plants: corn, rice, wheat.

Cotyledons • Plants can be divided in to groups: • Monocotyledons produce one seed leaf (cotyledon) Eg. corn • Dicotyledons produce two cotyledons. Eg beans • When conditions are right ( warmth, water, sun) a seed can germinate (start to grow), and will use the food in the cotyledons

Anatomy of a Seed 1. Seed coat provides protection 2. Stored Nutrients: endosperm in monocots, cotyledon in dicots. 3. Embryo: • Radicle - develops into roots • epicotyl - becomes the stem and leaves • hypocotyl - pushes up through the soil and protects the epicotyl in beans. • cotyledon

Anatomy of a seed

Monocotyledons Eg. corn

Seed Germination video • https: //www. youtube. com/watch? v=TE 6 xptjg. NR 0 • 5 min

Eggs contain the • zygote, • some nutrients, • protection (shell, jelly-like substance, or egg case).

Amniotic Egg • Amniotic Eggs are those that contain a single embryo surrounded by a shell. Eg birds and reptiles • Amnion- a fluid-filled sac, cushions the embryo • Yolk sac stores food for the embryo • Allantois holds waste produced by the embryo • Chorion (along with allantois) controls the movement of gases and wastes in and out of egg. • Albumen also cushions embryo and supplies additional nutrients • Chorion – outermost membrane

Mammals • Characterists

Three types of Mammals • Three different ways animals give birth: https: //www. youtube. com/watch? v=sz 3 Yv 3 On 4 l. E

Monotremes • Mammals that lay eggs. • duck billed platypus, spiny anteaters

How do animals protect their eggs/developing embryos? • bury their eggs (sea turtles) • Incubate them in a nest (birds) • Incubate them inside their bodies (all mammals except monotremes)

Embryos that develop in the Mother: Marsupials • Embryos of all mammals except duckbill platypus and spiny anteaters, develop inside the mother. • Embryos of Marsupials (kangaroos, koalas, and opossums) are only partially developed when born and finish developing in their mother’s pouch. https: //www. youtube. com/watch? v=2 l. CKc 8 t. URtc

Embryos that develop in the Mother: Placental Mammals • Embryos of placental mammals (humans, dogs, whales) develop inside the mother longer, inside a placenta that is connected to mother. • The fetus is attached to the placenta via an umbilical cord, which carries wastes out of fetus and nutrients in.

Sex Determination – more complicated than you thought • Ted Ed video • https: //ed. ted. com/lessons/sex-determination-more-complicatedthan-you-thought

Label the parts of the seeds

3. 5 Reproductive Technologies in Agriculture Selective breeding is used to produce desirable traits in plants and animals. VOCABULARY selective breeding artificial insemination Vegetative reproduction techniques are used to produce more plants faster. in vitro fertilization Artificial insemination and in vitro fertilization are used in the breeding of many domestic animals. genetically modified recombinant DNA technology organisms (GMOs) Fish hatcheries increase the number of fertilized eggs. Recombinant DNA technology is used to produce some drugs for humans. Some genetically modified organisms (GMOs) may have desirable traits, but since they contain DNA from other organisms, their existence raises moral and ethical concerns.