What is a Mammal?

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What is a Mammal?

• Ms. Hammer
• 2nd/3rd Grade Science

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Science Standards

• Strand Processes of Life
• Standard The student describes patterns of
  structure and function in
• living things.
• SC.F.1.2.2 Knows how all animals depend on
  plants.
• SC.F.1.2.3 Knows that living things are different
  but share similar structures.
• SC.F.1.2.4 Knows that similar cells form
  different kinds of structures.
• SC.F.2.2.1 Knows that many characteristics of an
  organism are inherited from the parents of the
  organism, but that other characteristics are
  learned from an individual's interactions with
  the environment.

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Objectives

• Students will be able to clarify at least three
  characteristics that designate a mammal.
• Students will be able to distinguish certain
  traits from animals in other classes, such as
  fish, reptiles, and amphibians.

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Mammal Characteristics

• All mammals are warm blooded.
• Most young are born alive.
• They have hair or fur on their bodies.
• Every mammal is a vertebrate.
• All mammals have lungs to breathe air.
• Mammals feed milk to their babies.

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Three Varieties of Mammals
Mammals constitute one class of the animal
kingdom and come in three varieties.

• MARSUPIALS
• Marsupials are mammals whose young are born
  very immature.
• Most female marsupials have pouches.
• MONOTREMES
• Monotremes are primitive, egg-laying mammals.
• Spiny anteaters and the duck-billed platypus
  are monotremes.
• PLACENTALSPlacental mammals are advanced mammals
  whose unborn young are nourished through a
  placenta.

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Are Humans Mammals?

• Our temperature stays about the same.
• We are born alive.
• We grow hair on our bodies.
• We have a backbone.
• We breathe air.
• Our mothers feed us milk when we are babies.
• Yes, we are! Humans are mammals.

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Activity

• What is the largest mammal?
• The blue whale grows up to 30 m in length
• and weighs up to 190 tons.
• The African elephant is the largest mammal
• living on dry land. It weighs up to 5.7 tons.
  
• The elk weighs up to 600 kg.
• What is the smallest mammal?
• The shrews are the smallest mammal in the world.
• They weigh about 1.5 g.

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Questions/Answers

• What do mammals have in common?
• They all have hair, mammary glands, are
  warm-blooded and use their lungs to breathe air.
• Every mammal is a vertebrate. That means mammals
  have a skeleton with a backbone.
• How do mammals give birth?
• All mammals give birth thanks to the sudden
  release of a flow of hormones. It is necessary to
  contract the uterus for the birth of the babies
  and for the delivery of the placentas.
• Mammals are bisexual, fertilization in internal.
  The embryo develops in the mother's body.
  Newborns are fed on milk from mammary glands.
• How do they stay warm?
• Their hair keeps them warm.

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Questions/Answers

• Where do mammals live?
• Most of mammals live on dry land. They live
  throughout the world some burrow in desert sand,
  some swing through tropical trees, some swim in
  arctic waters, some live in forests, some in
  mountains.
• How do mammals move?
• The way of moving depends on their habitats. The
  animals that live on the plains are adapted for
  fast running, forest animals can climb trees. The
  toes of cetaceans have fused to form flat,
  paddlelike flippers which enable them to swim.
  Bats are the only mammals that are able to fly.

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Questions/Answers

• What do mammals eat?
• Mammals are divided into three eating groups
• Herbivores, herbivores feed on grasses, roots,
  leaves, shoots, and fruits.
• Omnivores, omnivores feed on both plants and
  animals. Mammals use teeth, which are in the
  cavity of the mouth, to tear food.
• Carnivores, carnivorous mammals either hunt live
  prey or feed on dead animals.

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In Conclusion

• There are about 5,000 species of living mammals.