Mammalogy

Spring 2000

Exam 1
 
 

Name ___________________________________
 
  I. Multiple choice. Choose the single most appropriate answer. (3 points each)
 
 

For questions 1-2, select your answer from the options below:

a. b. c. (NOTE:  THESE WERE PHYLOGENETIC TREES)
 
 
 

1. Which of the above phylogenetic trees depicts a monophyletic lineage?
 

a.

b.

c.

d. None of the above


2. Which of the above phylogenetic trees depicts a paraphyletic lineage?
 

a.

b.

c.

d. None of the above


3. The Metatheria differ from the Prototheria and Eutheria in that they
 

a. Lay eggs

b. Are extinct

c. Do not have a cervix

d. Give birth to highly undeveloped young


4. Which brain structure allows communication between the two halves of the brain?
 

a. Hypothalamus

b. Corpus callosum

c. Tapetum lucidum

d. Corpus luteum
 

5. Which word describes a jumping or bounding form of locomotion?
 
a. Saltatorial

b. Fossorial

c. Amphibious

d. Arboreal
 

6. The incisors of the Rodentia remain useful despite tremendous amount of wear because they are
 
a. Closed-rooted

b. Open-rooted

c. Cursorial

d. Deciduous


7. Which of the following taxonomic groups possess a cloaca instead of a vagina?
 

a. Monotremata

b. Marsupialia

c. Multituberculates

d. Eutheria
 

8. Which of the following characteristics is found ONLY in present day mammals and in ALL species of present day mammals?
 
a. Pinnae

b. 4-chambered heart

c. Enucleate erythrocytes

d. Viviparous reproduction
 

9. The placenta serves to
 
a. Allow transfer of nutrients from mother to fetus

b. Allow exchange gases between mother and fetus

c. Produce hormones that maintain pregnancy

d. All of the above
 

10. Which of the following terms describes traits present into two species that were inherited from a recent shared ancestor?
 
a. Homology

b. Parallelism

c. Convergence

d. None of the above
 

11. Male accessory reproductive glands
 
a. Produce sperm

b. Produce substances that may coagulate to form a plug

c. Are located in the seminiferous tubules

d. None of the above

12. The function of vibrissae is
a. Insulation

b. Protection

c. Sensory

d. All of the above


 

II. Matching.

Match each feature of mammalian dentition with the most appropriate answer. Each answer may be used only once (14 points).

_____Crown

_____Heterodont dentition

_____Incisors

_____Elongated canines

_____Cheek teeth

_____Root

_____Edentate

_____Diastema

_____Occlusal surface

_____Tusk

_____Homodont dentition

_____Cementum

_____Dental formula

_____Enamel
 
 

a. Gradually accumulates to close of the root in closed-rooted teeth

b. Extremely hard substance that covers the crown of most mammalian teeth

c. Associated with myrmecophagy

d. Associated with aquatic carnivory

e. Indicates the number of incisors, canines, premolars and molars present

f. Area of the tooth that comes into contact with another tooth during chewing

g. Possessing different types of teeth with differing functions

h. Characteristic of herbivores

i. Premolars and molars

j. Associated with terrestrial carnivory

k. Square-shaped teeth that are used in nipping food

l. Covered primarily in dentine rather than enamel

m. Portion of the tooth above the gum line

n. Portion of the tooth below the gum line
 
 
 
 

Match each part of the mammalian skeletal system with the most appropriate answer from the answer set below. Each answer may be used only once (10 points).

_____Mandible

_____Ancestral phalangeal formula

_____2 occipital condyles

_____Cranium

_____Epiphyses

_____Malleus, incus, and stapes

_____Baculum

_____Axial skeleton

_____Appendicular skeleton

_____Turbinal bones
 
 

a. Contained within the auditory bullae

b. 2-3-3-3-3

c. Regions of bone growth

d. Components include cervical, thoracic, lumbar, sacral and caudal vertebrae

e. Allow for increase mobility of the head

f. Bone contained within the penis of many mammals

g. Contains the maxilla and rostrum

h. Associated with an acute sense of smell

i. Composed of the dentary bone

j. Shows high degrees of modification with differing modes of locomotion
 
 
 
 

III. Short answer (5 points each).

1. Describe the changes in jaw structure and hearing apparatus that accompanied the evolutionary transition from reptiles to mammals.
 

2. Describe or diagram the two basic types of mammary glands. What hormonal and sensory factors control the production of milk?
 

3. Mammals show many variations on the basic reproductive pattern, including delayed fertilization, delayed implantation and spontaneous abortion. Pick one such variant and describe how it differs from the basic mammalian reproductive pattern. Under what sorts of social/environmental conditions would the variant be advantageous?
 

4.  Each form of mammalian locomotion is associated with numerous anatomical specializations. Contrast the specializations of the limbs and tail typically found in arboreal species with those found in marine species.
 

5. Describe five characteristics of early mammals and indicate how each of these contributed to the success of mammals relative to their therapsid ancestors.
 

6. In 1693 John Ray proposed that mammals included those animals that (1) had blood, (2) breathed with lungs, (3) had 2 ventricles in their heart and (4) were viviparous. Evaluate this definition based on your knowledge of mammalian characteristics. Is this definition effective in differentiating mammals from other vertebrates? Which (if any) parts of Ray's chosen characteristics are diagnostic of mammals? Which current mammalian orders would be excluded from his definition?
 

7.  Mammals have numerous adaptations of the circulatory, respiratory and digestive systems that allow them to maintain a high metabolic rate. Describe five such structures and indicate the role of each in maintaining a high metabolic rate.
 

8. Describe the composition of hair (including the factors accounting for differences in coloration). What muscular and glandular structures are associated with the hair follicle and what are their functions?