View
228
Download
3
Category
Preview:
Citation preview
+
Biology 11Phylum ChordataSubphylum VertebrataClass Mammalia: US!
+ Mammalian Evolution
evolved from the reptiles
+Mammalia Objectives
General characteristics
complete body systems: circulatory, respiratory, integumentary, reproductive, nervous, skeletal, excretory, digestive
3 orders and example animals
+Mammalian Characteristics
4 chambered heart
Hair or fur
Diaphragm for breathing
Amniotic egg
Mammary glands for nursing young
Extensive post natal care
Learning and reasoning levels of behavior
+Advances and Characteristics of the body systems:1. Circulatory System
Complete four chamber heart and circulatory pattern
efficient transport system to every cell of the body
+
+2. Respiratory System
Highly efficient lungs
Chest muscles and a diaphragm to expand the chest cavity to increase capacity to hold air
+3. Body CoveringCovered with hair for insulation (modified scales) and sensing
All mammals are endothermic (generate heat to maintain their body temperature)
Have a layer of subcutaneous fat for insulation and food storage
+4. Reproductive SystemSexual reproduction
Internal fertilization & development
Amniotic egg: modified to include placenta in some mammals
Nurse young with mammary glands
Young born very immature - require extensive post natal care
+5. Nervous SystemMost developed nervous system in the animal kingdom
Great increase in cerebrum – responsible for thinking and learning
Very well developed senses
Behavior reaches learning and reasoning levels – infant care, mating & societies
+Brain Regions and Functions
Frontal Lobe thinking, planning, & central executive functions; motor execution.
Parietal Lobe somatosensory perception, integration of visual & somatospatial information.
Temporal Lobe language function and auditory perception involved in long term memory and emotion.
Occipital Lobe visual perception and processing.
+Class Mammalia
6. Skeletal SystemLimbs are well adapted for land & allow very rapid movement
Also adaptation of limbs to move in air & water
+7. Excretory Systemhighly developed kidney
– controls composition of body fluids
nitrogenous wastes from blood urea
urine = urea + water + other wastes
allowed mammals to live in many habitats ie. deserts – concentrate urine and feces conserve water
+ 8. Digestive System
highly developed and specialized organs responsible for digestion
Structure dependent on diet
1. Monotremes
Have fur & nurse young
Have a bird bill & lay eggs which they incubate outside body
Today represented only by Duck Billed Platypus and the two species of Anteater
ClassificationThe mammals are placed into three Orders:
+2. The MarsupialsFemales do not have a
uterus
Young are “born” immature and finish their development in a pouch
In pouch, young attach to mammary gland
Examples : Australia: kangaroos,
wallabies, possums and koala bears
+3. The Placental Mammals
Young develop completely inside the mother’s womb due to placenta
The placenta is an organ that allows for gas exchange and nutrient/waste exchange between mother & fetus
Most common order of mammals today - includes us!
+
Recommended