Lecture 21- Mammals

Question 1

Taxonomy of Mammals

Answer 1

• Class Mammalia
  Orders
  1- monotreme
  7- marsupials
  18- eutherians

Question 2

Characteristics of mammals (7)

Answer 2

• four-chambered heart
• lungs and diaphragm
• metanephric kidney and urea
• cerebral cortex
• endothermic homeotherms
• separates sexes
• parental care

Question 3

Whats adaptive radiation (2)

Answer 3

• one ancestor
• divergent evolution

Question 4

Whats convergent evolution

Answer 4

• different ancestors, similar traits

Question 5

List the adaptive radiation of limbs (4)

Answer 5

• Purpose: swimming, running, flying, hopping, gliding
• Chiroptera = hand wings
• Hair = Pelage (horns, antlers)
• Glandular skin: swear, scent, sebaceous and mammary glands

Question 6

Adaptive radiation of teeth and skull (5)

Answer 6

• single jaw bone
• baby and adult teeth
• 2 occipital condyles
• differentiated teeth
• Diastema (gap in between teeth)

Question 7

Sensory modalities

Answer 7

• Vision: large eyes= nocturnal, small eyes= pupil shape, bad eyesight
• Touch: whiskers (vibrissae), hands etc
• Hearing: different frequencies, acute
• Smell (olfaction)
• Electroreception

Question 8

Name the 2 Subclasses and give examples

Answer 8

Subclass
1. Prototheria, order monotremata: no placenta, lays eggs (echinda, platypus)
2. Theria: true placentals (marsupials)

Question 9

What are the 3 major mammal groups

Answer 9

1. Monotremes
2. marsupials
3. placentals