UWhat is an Animal?

1. To identify the characteristics of an animal. 2. To identify cell differentiation in the development of a typical animal. 3. To sequence the development of a typical animal.

1. Autotroph 2. Heterotroph 3. Sessile 4. Blastula 5. Gastrula 6. Ectoderm 7. Endoderm 8. Mesoderm 9. Protostome 10. deuterostome

 All animals have several characteristics in common: ◦ Eukaryotic ◦ Multicellular ◦ Reproduce ◦ Obtain their own food ◦ Protect themselves ◦ Most have specialized cells that form tissues and organs(nerves and muscles)

 Heterotrophic: animals must consume food to obtain energy and nutrients.  Animals depend either directly or indirectly on autotrophs for food.  dXno dXno  Some organisms cannot move to obtain food, like oysters and barnacles; these are called sessile because they are permanently attached to a surface.  Food comes to them!

 Most animal cells are differentiated and carry out different functions.  There are specialized cells for sense and seeking food and mates, and to allow them to identify predators.  Most animals grow and develop from fertilization- a zygote-.  Zygotes of different animal species all have similar, genetically determined stages of development.

 Most animals reproduce sexually.  Males produce sperm cells.  Females produce egg cells.  Fertilization occurs when a sperm cell penetrates the egg cell, forming a zygote.  Fertilization can be internal or external.

 Once the zygote forms, mitosis occurs and 2 cells form.  Once cell division begins the organism is known as the embryo.  The 2 cells divide into four cells and so on, until a cell-covered, fluid filled ball is formed called a blastula.

 After blastula formation, cell division continues.  The cells on one side of the blastula then move inward to form a gastrula- a structure made up of 2 layers of cells with an opening at one end.  The cells at one end of the blastula move inward, forming a cavity lined with a second layer of cells.

 The layer of cells on the outer surface of the gastrula is called the ectoderm.  The ectoderm will continue to grow and divide and develop into skin and nervous tissue of the animal.

 The layer of cells lining the inner surface is called the endoderm.  The endoderm cells develop into the lining of the animals digestive tract and into organs associated with digestion.

 The process of gastrulation continues until a layer of cells called the mesoderm forms.  Meso=middle  Mesoderm is found in the middle of the embryo.

 This is the 3 rd layer found in the developing embryo between the ectoderm and endoderm.  Develops into muscles, circulatory system, excretory system, and in some animals, the respiratory system.

 When the opening in the gastrula develops into the mouth, the animal is called a protostome. ◦ Snails, earthworms, and insects are examples  In other animals, including humans, the mouth does not develop from the gastrula’s opening.  Animals whose mouth does not develop from the opening, but from cells elsewhere on the gastrula is called a deuterostome.

 In insects and echinoderms, the embryo develops inside an egg into a larva; which does not resemble the adult version.

 Once the larval stage passes, most animals continue to grow and develop into adults.  Process repeats itself.

1. Identify and list the characteristics of a mouse that make it a member of the animal kingdom. 2. Explain why movement is an important characteristic of animals. 3. Identify cell differentiation in the development of an animal. 4. Describe gastrulation. 5. Name a land animal that is sessile. Why would this adaptation be a disadvantage to an animal in a land biome?

1. Project: 1.Deuterostome vs. Protostome: 1.Compare the 2 2.Explain the difference in formation 1.Add information about general cell differentiation in animal development and where these fall in embryonic development. 3.Give examples of types of animals in each category 4.Make it be 8 slides including the title slide 5.2 slides per student in the group