Flashcards in Ch 34 Chordates - Mammals Deck (55):
Synapsids were the first what?
Amniote group to diversify widely into terrestrial habitates
What were the dominant amniotes during the Permian period?
No temporal openings in the skull for muscle attachment
Two temporal openings in the skull for muscle attachment
Are reptiles anapsids, diapsids, or synapsids?
Were the earliest amniotes anapsides, diapsids, or synapsids?
One temporal opening in the skull for muscle attachment
Are mammals anapsids, diapsids, or synapsids?
Shared derived characteristic of mammals
How do mammals nourish their young?
Milk produced by mammary glands
Are mammals endothermic or exothermic?
What modification in mammals transmits sound in the middle ear?
Three bones of the skull
Mammals have what kind of heart?
Mammals have what kind of metabolic rate?
Composed of dead, keratin packed cells of the epidermal skin layer
How does hair grow?
By proliferation of cells at its base in the hair follicle
The shedding of all hairs at once
Benefits of hair
Long, coarse hairs that overlie underhair
Dense, soft, insulating hair
Bones extension of the skull
What covers horns?
A sheath of keratin
What covers antlers?
A highly vascular, soft skin
When are antlers covered by velvet?
During their growth phase
Are antlers shed?
Are horns shed?
Produce a watery fluid that cools the skin surface
Consist of cells that rupture to release sebum that conditions skin and hair
Produce nourishing milk
Have various function in chemical signaling including territoriality and mating
Teeth differentiated to perform specialized functions
Advances in mammalian locomotion
1) Limbs positioned under, rather than to the sides, of the body
2) Muscular diaphragm for inhalation, loss of abdominal ribs
3) Enlarged cerebrum for greater coordination
Three groups of mammals
Mammals that reproduce by laying eggs
Female monotremes possess what?
An abdominal pouch within which offspring complete their development after hatching
How are monotreme young fed?
From milk secreted by the mother's skin within the pouch
Pouched, viviparous mammals
When are marsupial young born?
At the embryonic stage of development
Where do marsupial young complete development?
In the abdominal pouch
How are marsupial young fed?
From the mother's nipples
Are most mammals, marsupials, monotremes, or eutherians?
How are eutherian young nourished during embryonic development?
Via a placenta
A vascular connection within the uterus between the mother and embryo
The period of development in the uters
How long can gestation last?
One to twenty-two months
What is seen between marsupials and eutherians?
Mammals that walk on their digits (toes)
Are ungulates considered digitigrades?
The odd-toed ungulates
Characteristics that distinguish humans from other apes
1) Upright posture and bipedalism
2) Larger brains
3) Reduced jawbones and jaw muscles
4) Shorter digestive tract
The larger brains of humans are capable of what?
2) Symbolic thought
3) Artistic expression
4) Manufacture and use of complex tools