Question

Mammals belong to...

		Anapsid lineage
		Synapsid lineage
		dinosaur lineage
		Diapsid lineage

1. The platypus and echinda belong to what group?

   		Monotremes
   		Aves
   		Metatheria
   		Eutheria

Most mammals have teeth that vary in structure and function meaning they are

		Monodont
		Heterodont
		Homodont
		Conodont

Metatherians spend more energy on ________ compared to Eutherians.

		Lactation
		Gestation
		Digestion
		Excretion

Maintaince of body temperature in Mammals is...

		ectothermic
		endothermic and homeothermic
		behaviorally ectothermic
		epithermic

Mammals all have the following characteristics EXCEPT...

		Ectothermy
		Body covered with hair at some point in development
		A well developed cerebral cortex
		mammary glands

Antlers

		Are permanent
		are hollow sheaths of keratin surrounding bone
		Occur in both sexes in ALL representatives
		Are composed completely of bone

ll mammals have how many middle-ear ossicles?

		2
		3
		4
		1

Eutherians have all of the following integument glands EXCEPT...

		Sebaceous
		Poison
		Sweat
		Scent

The frequency of estrus in temperate/arctic animals is generally __________ while the frequency in tropical animals is either ________ or __________.

		A menstrual cycle; monestrus or polyestrus
		Polyestrus; menstrual cycle or aestrus
		monestrus; polyestrus or a menstrual cycle
		Polyestrus; monestrus or a menstrual cycle

Answer 1

-Synapsids lineage

Mammals belong to synapsids lineage.Mammals are the only living synapsids.

- Monotremes

Platypus and echinda belong to the group monotremes.

Monotremes are mammals that lay eggs.

-Heterodont

mammals are typically heterodont.They have a variety of ttoth shapes that differ in structure and function.Most mammals have incisors,canines,premolars and molars.

-Lactation

Metatherians undergo a prolonged period of lactation than eutherians.Hence metatherians spend more energy on lactation than eutherians.

-Endothermic and homeothermic

Homeotherms are the organisms whose body temperature is relatively constant .They are commonly called warm-blooded or endothermic.Mammals belong to this category.

-Ectothermy

Ectotherms are cold blooded animals which include reptiles and amphibians.Mammals don't have ectothermic characterictics.

-Antlers are composed completely of bone.

-3

Three ear ossicles in mammalian middle ear are incus,malleus and stapes.

-poison gland

Eutherians have sabaceous glands,apocrine glands(scent glands) and sweat glands.They don't have poison glands.

-Monestrus;Polyestrus or a menstrual cycle

Arctic animals like polar bears are polyestrus.