Mammalia Class Overview

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Questions and Answers

What is the classification of mammals?

Class Mammalia (correct)

Kingdom Animalia (correct)

Phylum Chordata (correct)

Subphylum Vertebrata (correct)

Mammals are warm-blooded or ____.

endothermic

What is a disadvantage to endothermy?

constantly eating

What is an advantage to endothermy?

active during the day and night Signup and view all the answers

What are adaptations of warm-blooded animals?

4 chambered heart, body hair Signup and view all the answers

To maintain the high metabolic rate necessary for endothermy, a mammal must eat ____ times as much as an ectothermic animal of the same size.

10 Signup and view all the answers

Because they are endothermic, mammals can be ____.

active during the day and night Signup and view all the answers

Mammals have a diaphragm which ____.

helps to take in more oxygen, it is a muscle tissue under rib cage Signup and view all the answers

What are the 3 purposes of body hair for a mammal?

insulation, protection, and in some cases serves as a sense organ Signup and view all the answers

What is body hair made of?

keratin Signup and view all the answers

How many chambers in their heart do mammals have?

4 Signup and view all the answers

A 4 chambered heart allows for ____.

total separation of oxygenated and deoxygenated blood Signup and view all the answers

Pathway of blood through the heart and body of a mammal?

right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta, arteries, capillaries in tissue (gas exchange), veins, vena cava, right atrium Signup and view all the answers

Mammals nurse young with the milk from ____.

mammary glands Signup and view all the answers

What does oviparous mean?

egg laying ex: platypus Signup and view all the answers

What does viviparous mean?

giving birth to live young Signup and view all the answers

Mammals have large, well developed ____.

brains Signup and view all the answers

What does the cerebral cortex control?

memory, thought, imagination, creativity Signup and view all the answers

What does the cerebellum control?

senses and balance Signup and view all the answers

Mammals have a single lower jaw called the ____.

mandible Signup and view all the answers

What is the function of incisors and what animals are they important in?

cut and tear food; beavers and rabbits (herbivores) Signup and view all the answers

What is the function of canines and what animals are they important in?

impale and puncture; dogs (carnivores) Signup and view all the answers

What is the function of premolars?

in front of molars, flat on top, chewing and grinding food Signup and view all the answers

What is the function of molars?

flat on top, chewing and grinding food Signup and view all the answers

Class Mammalia is divided into major groups based on .

3; how the young develop Signup and view all the answers

Name the three groups of mammals.

Monotremes, marsupials, placentals Signup and view all the answers

Monotremes example and description.

oviparous (lay eggs) ex: platypus and echidna Signup and view all the answers

Marsupial examples and description.

underdeveloped young crawl to pouch to finish development ex: kangaroo, possum, koalas Signup and view all the answers

For placentals, the young develop inside a sac-like organ called the ____.

uterus Signup and view all the answers

What does the placenta do?

provides nourishment and takes care of excreted waste Signup and view all the answers

Placental mammals are ____ at birth.

fully developed Signup and view all the answers

Gestation is the ____.

length of pregnancy Signup and view all the answers

Examples of gestation:

rats- 2 weeks; elephants- 1.5 years Signup and view all the answers

Placental mammals are classified according to the ____ that help the animals live in their environment.

adaptations Signup and view all the answers

There are ____ orders of placental mammals.

18 Signup and view all the answers

Name the orders of class Mammalia in group Placentals that we learned.

Order Chiroptera, Rodentia, Cetacea, Carnivora, Artiodactyia, Primate Signup and view all the answers

Order Chiroptera are capable of ____.

powered flight Signup and view all the answers

Animals in order Chiroptera use ____ to hunt.

echolocation Signup and view all the answers

Example of an animal in order Chiroptera.

bat Signup and view all the answers

Which order is the largest in Class Mammalia?

Order Rodentia Signup and view all the answers

Adaptations in Order Rodentia.

big incisors (gnawers) Signup and view all the answers

Study Notes

Classification of Mammals

Kingdom: Animalia, Phylum: Chordata, Subphylum: Vertebrata, Class: Mammalia
Mammals are classified based on how their young develop into three major groups: Monotremes, Marsupials, and Placentals.

Characteristics of Mammals

Mammals are warm-blooded (endothermic), maintaining a constant internal body temperature.
Endothermy allows mammals to be active both day and night.
Disadvantage includes the need for frequent feeding; they must consume ten times more food than ectothermic animals of the same size.
Adaptations include a four-chambered heart and body hair made of keratin, serving three main purposes: insulation, protection, and sensory functions.
Mammals possess a diaphragm which aids in ventilation by increasing oxygen intake.

Anatomy of the Heart

Mammals have a four-chambered heart, ensuring complete separation of oxygenated and deoxygenated blood.
The blood circulates through a defined pathway: right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta, arteries, capillaries (gas exchange), veins, vena cava, back to the right atrium.

Reproductive Traits

Mammary glands produce milk to nourish young.
Oviparous mammals, such as the platypus, lay eggs, while viviparous mammals give birth to live young.
Gestation varies significantly across species; for example, rats have a two-week gestation period, while elephants have one of 1.5 years.
The placenta provides nourishment and removes waste for developing young in placentals.

Adaptations and Brain Development

Mammals are characterized by a well-developed brain, particularly the cerebral cortex (memory, thought, creativity) and cerebellum (senses, balance).
Mammals possess a singular lower jaw, known as the mandible, aiding in food processing and consumption.

Dental Adaptations

Different types of teeth serve specific functions:
- Incisors cut and tear food, critical in herbivores like beavers and rabbits.
- Canines impale and puncture, prominent in carnivores such as dogs.
- Premolars and molars are designed for chewing and grinding.

Groups of Mammals

Monotremes: Egg-laying mammals (e.g., platypus, echidna).
Marsupials: Young develop in a pouch post-birth (e.g., kangaroo, possum, koalas).
Placentals: Young are born fully developed after an extended gestation period, with 18 classified orders including Chiroptera (bats) and Rodentia (rodents, the largest order).

Orders of Mammals

Order Chiroptera: Capable of powered flight and utilize echolocation for hunting.
Order Rodentia: Adapted for gnawing with large incisors, encompassing a wide variety of species.

Conclusion

The class Mammalia exhibits a diverse range of life forms with complex adaptations that facilitate survival in various environments.

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Description

Test your knowledge on the classification and characteristics of mammals with this flashcard quiz. Understand concepts like endothermy, advantages and disadvantages of being warm-blooded, and adaptations specific to mammals. Perfect for biology students and enthusiasts alike!