Chapter 32, 32-1, 32-2, 32-3 Mammals Key Concepts

How are teeth of mammals adapted to their different diets?

As mammals evolved, the joint between the skull and lower jaw became stronger that that of reptiles, this allowed mammals to evolve larger, more powerful jaw muscles and different ways of chewing.

Name the three (3) groups of living mammals and describe the ways each develops.

Monotremes - egg-laying mammals. Marsupials - bear live young that complete their development in an external pouch. Placental - Internal patch where nutrients, oxygen, carbon dioxide, and wastes are exchanged.

How are powerful front claws and sticky tongues useful adaptations in mammals that feed on ants?

Powerful front claws and sticky tongues are useful adaptations in mammals to feed on ants because after the Cenozoic Era they had to adapt to their new surroundings.

When did mammalian ancestors diverge from reptiles?

The first true mammals appeared during the late Triassic Period, about 220 million years ago.

What is the function of the placenta?

The function of the placenta is to exchange, nutrients, oxygen, carbon dioxide, and wastes between embryo and mother.

Name the genera that currently make up the hominid fossil record.

The genera that make up the hominid fossil record are: Ardipithecus, Australopithecus, Paranthropus, Kenyanthropus, and Homo.

List two (2) ways in which mammals maintain homeostasis.

The high rate of metabolism helps mammals generate body heat. Also, mammals have external body hair and subcutaneous fat that help conserve body heat.

Describe the major primate groups and explain how they are related.

Two main primate groups are Prosimians and Anthropoids. Prosimians are small, nocturnal primates with large eyes that are adapted to seeing in the dark. Anthropoids are humanlike primates.

With regard to mammals, what was the result of continental drift during the Cenozoic Era?

When the continents drifted apart early in the Cenozoic Era, ancestors of different mammal groups were isolated from one another. Each landmass took with it a unique array of species.

List five (5) characteristics that most primates share.

Fingers, Toes, and Shoulders Well-Developed Cerebrum Binocular Vision

Compare and contrast hominids and hominoids. How are they similar? Different?

Hominoids have a smaller brain and are quadrupeds, walking on all fours but with flexible limbs. Hominids have an upright posture and bipedal locomotion. Apes belong to Hominoids and humans are in the Hominids category. As far as similarities they possess the same bones, Skull, Spinal cord, Arms, Pelvis, and Thigh bones.

Many humans have their wisdom teeth removed because their jaws are too small to accommodate those teeth. What might this suggest about the evolution of the human jaw?

Humans have their wisdom teeth removed because their jaw is too small, in my opinion this suggests that he human jaw has evolved in its own way to adapt to other foods available. There is no need for a humans jaw to be as large as other mammals.

Name the characteristics that are common to all mammals.

In addition to having hair and the ability to nourish their young with milk, all mammals breathe air, have four-chambered hearts, and are endotherms that generate their body heat internally.

How did the separation of the continents contribute to the development of New World and ld World monkeys?

In my opinion, I believe that the separation of continents contributed to new and old world monkeys because it caused changes in environment which caused the monkeys on each continent to evolve differently.

List the major orders of placental mammals.

Insectivores Carnivores Sirenians Artiodactyls Cetaceans Lagomorphs Chiropterans Xenarthrans Rodents Primates Perissodactyls Proboscideans