Intro to Animals/Fish and Amphibians Ch. 24/27-28
Chapter 24 Introduction to Animals Section 1: Animal Characteristics Section2: Animal Body Plans Section 3: Sponges and Cnidarians
Introduction to Animals Chapter 24 24.1 Animal Characteristics General Animal Features • The ancestral animals at the beginning of the evolutionary tree are eukaryotic and multicellular. • They developed adaptations in structure that enabled them to function in numerous habitats.
24.1 Animal Characteristics • Invertebrates- (Exoskeletons) Hard or tough outer coverings that provide a framework of support • Protect soft body tissues, Provide protection from predators
24.1 Animal Characteristics • Vertebrates- (Endoskeletons) Protect internal organs, Provide support for the body • Provide an internal brace for muscles to pull against • Movement: The evolution of nerve and muscle tissues enables animals to move in ways that are more complex and faster than organisms in other kingdoms.
24.1 Animal Characteristics • Fertilization occurs when the sperm penetrates the egg to form a fertilized egg cell called the zygote. • Internal fertilization- the egg and sperm unite inside the animals body ….humans • External fertilization- the egg and sperm unite outside the animals body ….fish
24.1 Animal Characteristics • What are the first few phases of early development in most animals. Please provide a visual for full credit. • The zygote undergoes mitosis and a series of cell divisions to form new cells.
24.1 Animal Characteristics • The cells continue to divide, forming a fluid-filled ball of cells called the blastula. • The blastula continues to undergo cell division as some cells move inward to form a gastrula.
Introduction to Animals Chapter 24
Introduction to Animals Chapter 24 24.1 Animal Characteristics Tissue Development • Endoderm • inner layer of cells in the gastrula • Ectoderm • outer layer of cells in the gastrula • Mesoderm • layer of cells between the endoderm and ectoderm
Introduction to Animals Chapter 24 24.1 Animal Characteristics
Introduction to Animals Chapter 24 24.2 Animal Body Plans Evolution of Animal Body Plans • Anatomical features in animals’ body plans mark the branching points on the evolutionary tree. • Relationships on this tree are inferred by studying similarities in embryological development and shared anatomical features.
Introduction to Animals Chapter 24 24.2 Animal Body Plans Symmetry • Similarity or balance among body structures of organisms • Asymmetry • Radial symmetry • Bilateral symmetry
Introduction to Animals • Have a fluid-filled cavity with tissue formed from mesoderm that lines and encloses the organs in the coelom Chapter 24 24.2 Animal Body Plans Body Cavities • Coelomates
Introduction to Animals • Have a fluid-filled body cavity that develops between the mesoderm and the endoderm rather than developing entirely within the mesoderm Chapter 24 24.2 Animal Body Plans Body Cavities • Pseudocoelomates
Introduction to Animals Chapter 24 24.2 Animal Body Plans Body Cavities • Acoelomates • Have solid bodies without a fluid-filled body cavity between the gut and the body wall
Introduction to Animals Chapter 24 24.2 Animal Body Plans Development in Coelomate Animals • Protostomes • The mouth develops from the first opening in the gastrula. • Deuterostomes • The anus develops from the first opening in the gastrula.
Introduction to Animals Chapter 24 24.2 Animal Body Plans Segmentation • Segmented animals can be “put together” from a succession of similar parts. • Can survive damage to one segment • Movement is more effective
Introduction to Animals Chapter 24 24.2 Animal Body Plans
Chapter 28 Fishes and Amphibians Section 1: Fishes Section2: Diversity of Today’s Fishes Section 3: Amphibians
Chapter 28 Fishes and Amphibians • Vertebrates have a vertebral column and specialized cells that develop from the nerve cord. • The vertebral column, or spinal column, is the hallmark feature of vertebrates. • A vertebral column can start as a notochord made of cartilage that protects the dorsal nerve cord then develop into bone.
Diversity of Today’s Fishes • Scientists have grouped fishes into three classes based on their body structure. Jawless Fishes (support system is cartilage) • Hagfish feed on soft-bodied invertebrates and dead or dying fish on the sea floor. • Lampreys are parasites that feed by attaching themselves to other fishes. Agnatha
Cartilaginous Fishes • All cartilaginous fishes have skeletons made of cartilage. • The flexible skeleton, rows of sharp teeth, a streamlined body, and placoid scales make sharks one of the top predators in the sea. • Skates and rays have flattened bodies that are adapted for living on the ocean floor.
Bony Fishes • There are two groups of bony fishes: the ray-finned fishes and the lobe-finned fishes. • Thin, spinelike rays support the fins of ray-finned fishes. • Lobe-finned fishes have muscular lobes and joints similar to those of land vertebrates.
Fishes and Amphibians Chapter 28 28.2 Diversity of Today’s Fishes Evolution of Fishes
Fishes • Jaws: Anterior gill arches evolved into jaws in ancient fishes. • The development of jaws allowed ancient fishes to prey on a larger range of animals.
Fishes • Paired Fins: A fin is a paddle-shaped structure on a fish or other aquatic animal that is used for balance, steering, and propulsion. • Paired fins reduce the chance of rolling to the side and allow for better steering during swimming.
Fishes and Amphibians Chapter 28 28.1 Fishes Scales • There are four types of fish scales. • Ctenoid scales • Placoid scales • Ganoid scales • Cycloid scales
Fishes • Gills: Fishes get oxygen when water that enters their mouths flows across their gills, where oxygen from the water diffuses into the blood. (Pressure: Volume relationship!!) • Gills are composed of thin filaments that are covered with highly-folded, plate-like lamellae.
Fishes and Amphibians Chapter 28 28.1 Fishes Circulation • Vertebrates have a closed circulatory system. • In most fishes, the heart consists of two main chambers—the atrium and the ventricle.
Fishes and Amphibians Chapter 28
Fishes and Amphibians Chapter 28 28.1 Fishes Feeding and Digestion • Most fishes swallow their food whole, passing it through a tube called the esophagus to the stomach, where digestion begins.
Fishes • Explain the importance of the lateral line and the swim bladder. How does each work?
Fishes and Amphibians Chapter 28 28.1 Fishes The Brain and Senses • Color vision, chemical detection, hearing, and balance are coordinating in the brain. • The lateral line system is a special sensor that allows fish to detect even the slightest movements in water.
Fishes and Amphibians Chapter 28 28.1 Fishes Reproduction • The majority of fishes reproduce through external fertilization. • Male and female fishes release their gametes near each other in the water in a process called spawning.
Fishes and Amphibians Chapter 28 28.1 Fishes Movement • Fishes are well adapted to swimming in the water. • Streamlined shape • Paired fins • Swim bladder • Fishes move through the water by contracting muscle groups on either side of their bodies.
Lamprey and Perch • What are the four differences between the lamprey and the perch.
Fishes and Amphibians Chapter 28 28.3 Amphibians:
Fishes and Amphibians Chapter 28 28.3 Amphibians Characteristics of Amphibians • Most amphibians begin life as aquatic organisms. Tadpole • After metamorphosis, they are equipped to live life on land. Frog
Fishes and Amphibians Chapter 28 28.3 Amphibians Feeding and Digestion • Most frog larvae are herbivores, whereas salamander larvae are carnivores. • As adults, their diets are similar as both groups become predators. Intestines must shorten. • The digestive system of an amphibian is very similar to that of a fish.
Fishes and Amphibians Chapter 28 28.3 Amphibians Respiration • As larvae, most amphibians exchange gases through their skin and gills. • As adults, most breathe through lungs, their thin, moist skin, and cavities in the mouth.
Fishes and Amphibians Chapter 28
Fishes and Amphibians Chapter 28 28.3 Amphibians Circulation • Amphibians have a double-loop circulatory system. • Amphibians have three-chambered hearts.
Fishes and Amphibians Chapter 28
Fishes and Amphibians Chapter 28 28.3 Amphibians Reproduction and Development • In most amphibians, fertilization is external and the shell-less eggs must be laid and fertilized in water. • Tadpoles hatch from the egg and undergo metamorphosis from a fishlike animal to an air-breathing one.
Fishes and Amphibians Chapter 28 28.3 Amphibians Amphibian Diversity • Scientists classify modern amphibians into three orders. • Order Anura includes frogs and toads. • Order Caudata includes salamanders and newts. • Order Gymnophiona includes caecilians. Legless and wormlike!! Page 839.
Fishes and Amphibians Chapter 28 28.3 Amphibians Evolution of Amphibians