Mammalia By: Jillian Roberts and Rachel Baker

Phylogenetic Tree

Characteristics Used to Place Organisms in Taxons To place an organism into the kingdom of Animalia the organism must inhabit most of these general characteristics: Multicellular eukaryotes Have muscle tissue and also nerves to support body Are mobile at some time in their life cycle Reproduce sexually Undergo cellular cleavage as zygotes

Characteristics Used to Place Organisms in Taxons (2) After taxonomists discover the kingdom to which place an organism they look at slightly less general characteristics to decided which Phylum an organism belongs to, Mammals belong to the Chordata Phylum, the qualities that are needed to be in this phylum are as follows: Vertebrae Brain (enclosed within a skull) Endoskeleton A closed circulatory system with a heart Excretion through kidneys Separate males and females with sexual reproduction

Characteristics Used to Place Organisms in Taxons (3) Once deciding which phylum to place the organism, taxonomists must pick which class to place the organism. Mammals are all placed into the class Mammalia. Each have most of the following characteristics: Body hair 3 middle ear bones (malleus, incus, and stapes) Nourish their young with milk that females produce (in modified sweat glands)

Human Life Cycle Begins with the fertilization of an egg with sperm, this would then become a fetus. The fetus remains in the womb of a woman for around nine months before leaving the womb as a baby. The baby will grow very fast into a toddler, and then into a child. The child will continue to grow and will go through a process called puberty, this is where reproductive organs become active. Next in the human life cycle are the teenage years. Once the teenager ages they enter a time in their life know as adulthood. This is the longest stage in the human life cycle. After adulthood comes the senior years which are present prior to death.

3 Organisms OrganismKingdomPhylumClassOrderFamilyGenusSpecies HumanAnimaliaChordataMammaliaPrimatesHominidaeHomoSapien Killer Whale Animalia MammaliaCeteDelphinidaeOrcinusOrca Aye-AyeAnimaliaChordataMammaliaPrimatesDaubentoniidaeDaubentoniaMadagascariensis

Features Used for Getting Food and Locomotion Mouth: mastication, some digestive enzymes Esophagus: simple transport tube Stomach: most initial digestion, some physical processing Small intestine: digestion continues, some absorption Caecum: diverticulum at junction of small and large intestines, digestion continues Large intestine: absorption Rectum: final absorption Locomotion: The majority of land mammals travel across land via 2-4 legs. The modes of locomotion used by animals have been divided up into more than 30 different types. It is not unusual for an animal to change from one type of movement to another. Mammals such as whales that live in the water swim using their tale and fins as there means of locomotion. The very view birds that are in the Mammalia Class use their wings to fly as their main source of movement.

Features Used for Getting Food and Locomotion (2)

Circulation Mammals have a closed circulation, which means that all their fluids stay within certain parts of the body and can be transported to body parts in need. Blood for example stays within the mammals and flows throughout different body parts via vessels and arteries.

Gas Exchange In mammals the release of CO2 is a process which takes in air (O₂) from the environment to which they preside and flows through the body throughout the bloodstream to certain cells. The air then undergoes the process of cellular respiration. The result of this complex process is the release of CO2.

Digestion The digestion of mammal varies from species to species but there is a general outline for both Carnivores and also Herbivores. The average carnivore will bite off large amounts of meat which they will crew using their teeth. It then travels down the esophagus into the stomach. Upon entering the stomach the chewed meat will be broken down into its basic components by stomach acids. These components then enter the bloodstream. What is left in the stomach moves into the large intestine where water is taken from it and then it leaves the body in the form of feces.

Digestion (2) Herbivores break down the plants they eat by first chewing them to break down the fiber. Next the chewed food enters the stomach where acids, enzymes and also bacteria begin digestion. The bacteria undergoes the process of fermentation. Their digestive system then forces the already eaten food back into their mouth to begin the process of ‘chewing the cud’ this is where they re-chew digested food. This will increase the speed of breaking down the food so that it can be released from their bodies as waste faster.

Excretion of Wastes Excretion in mammals happen in following ways: Urine- Through Kidneys Carbon Dioxide- Through lungs Food waste- Through Anus Urea and Lactic acid- Through Skin

Changes in Classification The classification of the mammalia is one that has not seen dramatic changes. There have however been many changes in levels found after that class due to the discovery of new species and also from scientists gaining a better understanding of molecular genetics. The names of species that have been modified due to evolutionary changes.

Interesting Facts! The largest mammal is the blue whale. It is also the biggest animal of any kind to have ever lived on Earth. It can grow to 30 meters in length and weigh around 30,000 pounds. The smallest mammal in the world is the Kitti's hog-nosed bat which grows to only 1.3 inches in length and weighs 2 grams.

Interesting Facts! (2) The Australian continent is the only place in the world where all three major classes of mammals are found Ex. Monotremes, Placentals and Marsupials The bowhead whale has the longest lifespan among mammals and can live for 100 years or more.

Bibliography of Mammals of Mammals