Exam 2
Answer key
I. Multiple choice
- b
- c
- d
- c
- a
- b
- b
- d
- c
- d
- a
- b
- d
- Short answer
1. Arvicoline population cycles
Rising phase |
Peak phase |
Declining phase |
Low density phase |
long breeding season |
short breeding season |
short breeding season |
short breeding season |
early sexual maturity |
late sexual maturity |
late sexual maturity |
|
high survival |
high survival |
low survival |
low survival |
high dispersal (vigorous individuals) |
high dispersal (old, young and weak individuals) |
|
|
- Shrews (family Soricidae) are venomous. The venom is produced in the submaxillary glands (salivary glands) atthe base of the lower incisors. Venom flows from the gland along a groove in the lower incisor when the shrew bites its prey. The bite is usually delivered to the base of the neck of the prey, where it can quickly travel to the brain and exert its neurotoxic effects. Venom allows these shrew to subdue prey that are larger than themselves (eg, frogs and small mammals).
- Anatomical specializations for feeding on ants and termites could include:
- elongate rostrum
- long, sticky tongue
- long, strong claws
- broad forefeet
- powerful forelimbs
- splayed forelimbs
- roughened pyloric portion of the stomach
- loss of or reduction in number of teeth
Examples:
- Xenarthra (anteater)
- Pholidota (pangolin)
- Tubulidentata (aardvark)
- Monotremata (echidna)
- Characteristics in bold were sufficient in and of themselves. Other characteristics had to be mentioned in combination to get full credit.
- Lagomorpha- fenestrated skull, peg incisor behind medial (middle) incisor , jointed cranium
- Tubulidentata-conical or figure-8 shaped cheek teeth, vertical pulp cavities through cheek teeth
- Insectivora-no auditory bullae, absence or reduction of zygomatic arch
- Myrmecophagidae- no teeth ; elongated, tubular rostrum
- Hystricidae-large, chisel-shaped incisors ( a single pair), large hole in front of zygomatic arch
- Tarsiidae - huge orbitals , foramen magnum directly below cranium
- To get full credit, you must have mentioned at least 2 traits for each type of locomotion.
brachiation
- elongated, curved fingers
- reduced or no thumb
- long forelimbs (relative to hind limbs)
- mobile shoulder and hip joints
- opposable hallux
- no tail
- broad thorax
vertical clinging and leaping
- relatively long hind limbs
- powerful thighs
- elongate tarsus (in Tarsiidae)
- prehensile hands and feet
- reduced or absent tail
terrestrial quadrupedalism
- reduced or absent tail
- near equal fore-to-hind limb ratio
- limbs move in a single plane (reduced mobility) narrow thorax
- relatively short digits
6.
CF=constant frequency
Long duration, constant pitch vocalization
Best for discriminating whether an object is moving towards or away from the bat (using the Doppler effect)
FM=frequency modulated
Relatively short duration vocalization, with pitch changing from high to low
Best for obtaining fine-grained information about the size, shape and position of features in the environment
7. Similarities could include:
- large, rootless, chisel-shaped incisors
- absence of canine teeth
- diastema
- large, often rootless cheek teeth with complex occlusal surfaces
Differences could include:
- presence of a second, peg incisor directly behind the large top incisor in the Lagomorpha
- upper jaw is wider than lower jaw in the Lagomorpha, so that only one side can occlude at a given point in time
Both orders feed primarily in plant material, which is tough and takes a great deal of mechanical processing (ie, chewing) in order to digest.
8. Each of the following bits of information was worth 0.5 points.
Morphological specializations
- long rostrum
- long, protrusile tongue
- brush-like tongue
- specialized body hairs to trap pollen grains
- wing shaped to allow hovering
Plant characteristics
Very large flowers
Robust flowers
White colored flowers
Flowers dangle from stalks
Flowers have pungent smell
Flowers bloom at night
Only one or a few flowers per plant bloom on a given night Produce copious amounts of nectar
Elongate stamens for more effective transfer of pollen
9.
- Nictitating membrane covers and protects eyes
- Valvular ears
- Valvular nostrils and specializations of the epiglottis that permit opening of mouth underwater provide protection for the lungs