Characteristics of Life Lesson 1

Invertebrates

Section Objectives: Identify the characteristics of animals. Identify cell differentiation in the development of a typical animal. Sequence the development of a typical animal.

What is an animal? Name the all the different types of animals you see in the pictures below. Fawn, pig, goat girl and calf

Characteristics of Animals A. Must be able to obtain food. B. Be able to digest food. C. Adaptations D. Reproduce E. Movement

Characteristics of Animals 9:57 min

Sessile Organisms that are permanently attached to one spot. These animals have some moveable parts for gathering food and protection. Ex: Sea anemone

camo

Motile Free moving stage in the life cycle of a sessile animal. Use the water movement to move.

What might be some advantage to being motile in the early parts of the life cycle of a sessile organism? Advantage is so they might move away from parent. Start a new colony etc.

Glycogen A polysaccharide used for food storage.

Fertilization Occurs when a sperm penetrates the egg. May occur internally or externally.

Answer is: All 2. Movement, Be able to Obtain food, Able to digest food, Adaptations, Reproduce 1. 2.

Multicellular heterotrophic eukaryotes Have more than one cell and must obtain food and energy by eating other organisms.

Embryo development 1. Fertilization 2. Zygote 3. Cleavage- zygote divides 4. Blastula - when the embryo becomes a hollow ball of cells. 5. Gastrula - As the blastula continues to develop, certain cells move inward from the surface, forming a two - layered, cup- shaped embryo.

Body Plans 6:18 min

The animals pictured below are probably ______. Sessile

Areas of the gastrula A. Ectoderm - cells on the outer surface. B. Endoderm - Layer of cells lining the inner surface. C. Mesoderm - A layer some animals have that is located between the ectoderm and endoderm. Area where different organs and tissues develop.

18. Endoderm 19. Endoderm, Ectoderm, Mesoderm 16. Openings in gastrula 17. Ectoderm 18. Endoderm 19. Endoderm, Ectoderm, Mesoderm 20. Endoderm 21. Mesoderm 22. Ectoderm 23. Mesoderm

Protostome - proht uh stohm Animal with a mouth that develops from the opening in the gastrula. Snails, earthworms, and insects are examples of protostomes.

Deuterostome – dew tihr uh stohm Animal in which the anus develops from cells elsewhere on the gastrula . Sea Cucumber

Cell Differentiation in Animal Development Sperm cells Fertilization Egg cell Formation of mesoderm First cell division Endoderm Mesoderm Ectoderm Gastrulation Additional cell divisions Formation of a blastula

Larva Intermediate stage of development. Usually bears little resemblance to the adult animal. (Ex; butterfly)

You have just discovered a new organism that you think is an animal You have just discovered a new organism that you think is an animal. In order to be classified an animal, what characteristics must it have? Movement, Reproduce, Adaptation, Able to digest food, Be able to obtain food

If the animal described below is a sessile organism, write yes If the animal described below is a sessile organism, write yes. If not write NO A. Barnacles attached to a ship’s hull. B. A spider lying in wait in the center of its web. C. Coral larvae drifting in a tropical ocean. D. Sponges growing on the outside of crab’s shell A. Yes B. No C. No D. Yes

The animal’s digestive tract forms from the _________ layer. Endoderm

1. _____ animal with a mouth that develops from the opening in the gastrula. 2. _____ embryonic structure of an animal that consists of two cell layers . 1. Protosome 2. Gastrula

3. ______ describes organisms that don’t move from place to place. 4 3. ______ describes organisms that don’t move from place to place. 4. ______ layer of cells lining the inner surface of the gastrula. 5. _____ layer of cells on the outer surface of the gastrula. 3. Sessile 4. Endoderm 5. Ectoderm

6. ______ single layer of cells surrounding a fluid-filled space that forms during early development. 7. ____ third cell layer formed in the developing embryo. 6. Blastula 7. Mesoderm

More Invertebrates

Section Objectives: Compare and contrast radial and bilateral symmetry with asymmetry. Trace the phylogeny of animal body plans. Distinguish among the body plans of acoelomate, pseudocoelomate, and coelomate animals.

Body Plans Most can be compared on the basis of symmetry and segmentation.

Body symmetry Arrangement of body parts around a central axis. Balance in proportions of an object.

Radial symmetry Body parts radiating from a central axis. Can be divided along any plane, through a central axis. Ex: Sea star

Bilateral symmetry Body parts arrange in pairs on either side of a central axis. Generally have more complex sense organs. Tend to be located in the anterior end. Animals can generally move faster. Can divide down it’s length into similar right and left halves.

Asymmetry Irregular shaped body. Usually a sessile animal. Ex: sponge

What shape? Radial

What shape? Bilateral

Dorsal Refers to back surface.

Ventral Refers to belly surface.

Posterior Refers to rear or tail end.

Anterior Refers to front or head end.

Segmentation Body parts divided into repeated units or segments. Ex: earthworm, human vertebrae

Acoelomate Organisms that have the 3 cell layers, (ectoderm, endoderm, and mesoderm) , but no body cavities. Ex: flatworm Acoelomate Flatworm Ectoderm Mesoderm Endoderm Body cavity Digestive tract

Coelomates (see loh mayts) Coelom - A fluid filled space that is completely surrounded by mesoderm. Greatest diversity of animals is found in this body plan.

Ex: earthworms, humans, insects. Coelomate Segmented Worm Ectoderm Mesoderm Endoderm Body cavity Digestive tract Coelom

Pseudocoelom - (sewd uh see lum) Fluid - filled body cavity partly lined with mesoderm. Organisms called pseudocoelomates. Ex: roundworm Anus Intestine Mouth Round body shape

1. Bilateral Symmetry (could divide into pairs) 2. Moves, legs, central axis 3. Tree 4. Asymmetry (No shape, irregular) 5. Probably sessile 6. Stew 7. Radial Symmetry (Divide any place equal, or same) 8. Not as complex, can’t move as fast 9. Flower

Exoskeleton Hard encasement on the surface of an animal. Ex: insects, crabs, snails and clams.

Endoskeleton Rigid framework inside of an animal. This skeleton in echinoderms may be made of Calcium carbonate (CaCO3); cartilage as in sharks or bones. Ex: human, vertebrates.

Vertebrates Animals with a backbone. All are bilaterally symmetrical animals that have endoskeletons.

Invertebrates Animals without a backbone. Jellyfish Sea Anemone Coral

Animal fossils become abundant at the beginning of the Cambrian period. Scientist have traced evolution back in time to this period.

Fossils Oldest known fossils of animals are more than 600 million years old. Scientist theorize may be as early as 700-800 million years ago.

Animal Ancestors 9:47 min

Instruments

Instruments

Instruments Microscope Triple Beam Balance

Question 1 A. radial symmetry C. bilateral – anterior B. asymmetry A sea star exhibits _______. A. radial symmetry C. bilateral – anterior B. asymmetry D. bilateral – posterior

The answer is A, radial symmetry.

Question 2 A. jellyfish B. starfish C. octopus D. sea urchin Which of the following animals does NOT exhibit radial symmetry? A. jellyfish B. starfish C. octopus D. sea urchin

The answer is C. An octopus exhibits bilateral symmetry.

Question 3 As you look at the cross sections of animals in the following figure, give the reason why animals with the basic cross section in the middle and on the far right will tend to be larger than animals with the far-left cross section.

Question 3 Coelomate Segmented Worm Pseudocoelomate Roundworm Acoelomate Flatworm Pseudocoelom Coelom Ectoderm Mesoderm Endoderm Body cavity Digestive tract

Answer The development of fluid-filled body cavities made it possible for animals to grow larger because it allowed for the efficient circulation and transport of fluids, and support for organs and organ systems.

Question 4 A. eukaryotic B. multicellular C. heterotrophic Which of the following is NOT a characteristic of animals? A. eukaryotic B. multicellular C. heterotrophic D. prokaryotic The answer is D.

Question 5 A. live only underground B. are autotrophs Sessile animals _______. A. live only underground B. are autotrophs C. are permanently attached to a surface D. live only on land

The answer is C. Sessile animals are permanently attached to a surface.

Question 6 A. digestion B. physically responding to a light stimulus Ingestion is another word for _______. A. digestion B. physically responding to a light stimulus C. breathing D. eating

The answer is D, eating.

Question 7 A. sponge – spicule B. mollusk – shell C. flatworm – coelom Which of the following pairs of terms is not related? A. sponge – spicule B. mollusk – shell C. flatworm – coelom D. coral – larvae The answer is C.

Question 8 A. endoskeleton B. backbone C. bilaterally symmetrical Which of the following is NOT a vertebrate feature? A. endoskeleton B. backbone C. bilaterally symmetrical D. pseudocoelom The answer is D.