Lab 8 Animal Adaptations

Question 0

What does fossil records indicate about earliest mammals

Answer 0

1. Small
2. Shrew- like
3. Fed on small prey and insects
4. Evolutionarily conservative for 10s of millions of years

Question 1

Variation that we see among species in coloration, morphology and behavior reflects

Answer 1

Adaptations to specific environments or to particular ecological lifestyles

Question 2

Evolution of early mammals after extinction of dinosaurs ( 65 million years ago)

Answer 2

Mammals underwent adaptive radiation and evolved into a wide variety of life forms

Secondary bouts of adaptive radiation later gave rise to most of our modern groups such as primates, rodents and ungulates

Question 3

Mammals evolved from

Answer 3

Reptiles

Question 4

How are mammals distinguished from reptiles

Answer 4

A variety of derived traits
Presence of hair
Mammary glands which produce milk
Internal development of embryos
Tooth morphology ( reptiles.... Homondont/ mammals heterodont)

Question 5

Homodont

Answer 5

. Found in reptiles

. Condition where all teeth are roughly similar in size and shape

Question 6

Heterodont

Answer 6

. Found in mammals

. Teeth differ in size and shape

Question 7

What does tooth shape and number correlate with

Answer 7

. Feeding biology of mammals

Question 8

What caused a dramatic increase in the diversity of tooth shapes and sizes

Answer 8

Adaptive radiation

Question 9

What are the 4 major types of teeth found in mammals

Answer 9

Incisors
Canines
Premolars
Molars

Question 10

Why do reticle have homodont teeth

Answer 10

?

Question 11

Incisors

Answer 11

Incisors…. Tearing
Canines…. Piercing
Premolars and molars ….. Crushing and grinding

Question 12

DENTAL FORMULA

Answer 12

. Used to describe the number and kinds of teeth found in mammals
. Consist of the number and type found on the upper and lower portions of one side of the mouth. Then multiplied by 2 gives the total number of teeth in the mouth

Question 13

Carnivores

Answer 13

CARNIVORES : such as dogs and cats, generally have large pointed incisors and canine that can be used to kill prey, or rip or cut away pieces of flesh. Jagged premolars and molars crush and shred food.

Question 14

Herbivore

Answer 14

Such as horses and deer, usually have molars and premolars with broad ridged surfaces that grind tough plant material. Incisors and canines are modified to bite off pieces of vegetation. In some herbivores canines are absent

Question 15

Omnivores

Answer 15

As in humans are adopted to eating both plants and meat. 
Incisors for biting
Canines for tearing 
Premolars for grinding 
Molars for crushing

Question 16

Purpose of hair

Answer 16

To provide heat

Question 17

2 classifications of hair

Answer 17

Guard hair

Under fur

Question 18

Guard hairs

Answer 18

Larger, coarser hairs that are more apparent on the outer surface of the body

Question 19

Underfur

Answer 19

Is composed of finer, shorter hairs that are not apparent until the fur is parted

Question 20

Why is hair shed

Answer 20

Because they are dead at maturity

Question 21

Function of hair

Answer 21

Heat conservation
Special air filled for buoyancy caribou
Camouflage 
Water repellent 
Protection from predators