What is an Animal? Animal Characteristics Chapter 4 & 5

Words to Know Homeostasis Chordate Adaptation notochord Vertebrate vertebra Invertebrate ectotherm Tissue endotherm Organ molting Organ system cartilage Radial symmetry muscle Bilaterial symmetry joint Bird Placenta

What is an Animal ? All animals are multicellular organisms that feed on other organisms and perform the same basic functions: obtaining food and oxygen, keeping conditions stable, move in same way and reproduce. Keeping internal body conditions stable is known as homeostasis.

How are animals classified? Animals are classified according to how they are related to other animals. These relationships are determined by an animals body structure, they way they develop and their DNA. All animals are either vertebrates or invertebrates

Animal Body Plans All animals are made up of many cells. These cells are than organized as tissues. In most animals, tissues combine to form organs and organs work together to form an organ system.

How is Symmetry Related to Body Structure? Types of symmetry : Radial, bilateral and asymmetrical.. The bodies of animals without symmetry are organized simply, with some cells but no specialized tissues. Animals with radial symmetry have complex body plans with tissues and usually with organs. Animals with bilateral symmetry have organ systems

Introduction to Invertebrates Animals that do not have a backbone are invertebrates. The main groups are sponges, cnidarians, flatworms, roundworms, segmented worms, mollusks and echinoderms.

Sea Sponge Cnidarian Worms Mollusks

Arthropods Echinoderms

Introduction into Vertebrates At some point in their lives, all chordates have three characteristics: a notochord, a nerve cord and pouches in their throats. Most chordates also have a backbone Notochord is a flexible rod that supports a chordates back All chordates have a nerve chord that runs down their back. Throat pouches disappear before birth, aside from fishes and lancelets which have gills.

How do Vertebrates Control Body Temperature? Some vertebrates do not produce much internal heat. Therefore, their body temperatures change with the environment. Other vertebrates control their internal heat and maintain a constant body temperature. Ectotherm – Body temperature changes with environment Endotherm – Body temperature can be controlled constantly.

Skeletons and Muscles A skeleton is a framework that shapes and supports an animal, protects its internal organs and allows it to move in its environment. There are two types of skeletons – Endoskeleton and Exoskelteon

Compare and Contrast Endotherms Ectotherm Both

What is the role of Muscles ? Muscles help animals move their body parts. Muscles make up most the walls of some blood vessels When the muscles contract or get shorter they squeeze blood through the vessels. Muscles attached to skeletons always work in pairs. When one muscles contracts the other relaxes.

The Nervous System A nervous system allows animals to detect signals in their environments, process these signals and react to them. A signal that causes an animal to react is some way is called a stimulus. A response is an animals reaction to a stimulus. The simplest nervous systems are netlike arrangements of neurons throughout the body. The most complex systems have a nerve cord and a brain. The more complex nervous systems have sense organs: eyes, ears, and noses that detect stimuli

Animal Movement An animal moves about when the nervous system, muscular system and skeletal system work together to make movement happen. Animals that live in water, on land, or in the air have different adaptations for movement. Moving in water - Water vascular system, fins, jet propulsion, streamlined bodies and webbed feet On Land Animals - Body muscles, arms and legs In Air – Feathers, various types of wings, skin and bones

Moving in water and air

Lets Review What are the 5 main functions of animals? Describe how the symmetry of a sea star, a sponge, and a fish differ. What is the highest level of organization an animal can have? Why is the endoskeleton important? List three functions of the skeleton. Describe how your muscles work to help you kick a ball What are three reasons why an animal might need to move about?