BIO Exam 4: Chordata VII (mammals)

What is the critical innovation of Class Mammalia?

milk and hair

What lineage gave rise to all modern animals?

therapsid

What is diphyodont tooth replacement in mammals?

mammals grow 2 sets of teeth

True or false: Class Mammalia has high morphological diversity

True

What are the 5 defining traits of the Class Mammalia?

1. Presence of hair and mammary glands

2. Endothermic (like birds)

3. Placenta for embryo nutrition

4. Tooth specialization

5. Highly advanced brain and sense organs

What skin modification is unique to mammals?

hair and mammary glands

What are the two types of hair forming the pelage?

the underhair and the guard hair

What is the characteristic of the underhair?

dense and soft for insulation

What are the characteristics of the guard hair?

coarse and long for protection and coloration

What are the 3 unique hair glands in Class Mammalia?

1. sweat glands

2. scent glands

3. mammary glands

What are the various functions that hair provides for species in the Class Mammalia?

thermal insulation, concealment, waterproofing, dense protective bristles, tactile sense

What is linked to tooth morphology (similar to beak morphology in birds) for Class Mammalia?

diet

What type of teeth allows for regional specialization?

Heterodont teeth

True or false: Class Mammalia has internal fertilization

True

What are the 3 reproductive strategies of the species in Class Mammalia?

1. Monotremes (egg-layers)

2. Marsupials (develop in pouches)

3. Placental

True or false: Most mammals are placental

True

True or false: All species in Class Mammalia rear their young on milk

True

What are the characteristics of species in the Class Mammalia’s respiration and limb modification?

they have a 4-chambered heart, high metabolic rate, diaphragm, secondary palate, and limb modification

True or false: Very few mammals make routine migrations

True

How do mammals defend territories?

they use scent glands

What was Darwin’s hypothesis for the evolution of humans ONLY based on?

anatomical similarities

Why was Darwin’ hypothesis wrong?

fossil, biochemical, and chromosomal evidence show common decent from apes

What are humans and apes both classified as?

primates 

True or false: The evolutionary importance are the grasping fingers between humans and apes

True

What were the first Homo sapiens called?

Neanderthals

What continent did humans first appear?

Africa

At about what time did Neanderthals become extinct?

30,000 years ago