Reproduction

How many vaginas and uteruses does a kangaroo have

Two

Does the shape of sperm vary between monotremes, metatherians and eutherians

Yes, monotremes are elongate

What is unique about monotremes testes

They only have abdominal instead of inguinal or scrotal

What lineage has seminal vescles

Eutherians (Mono and meta missing)

In which lineage is a shell membrane absent

Eutherians

Which lineages have mammary glands

Mono, mesa and eutherians

Which lineages have teats

Metatherans and eutherians

Diffuse

Occur over a large surface area

Cotyledonary

Regurly spaced clusters

Zonary

Band of villi encircles chorion

Discoidal

villi in disk-shaped zone

Placental variation take home

We have 4 different placental varieties which are not phyllogenitically constrained

What are the different strategies for development of offspring

High time in womb, short lactation or short time in wound, long lactation period

Which lineage is lactation the longest for

Metatherians

Do metatherians or eutherians spend more resources on their offspring (assuming they are the same size)

No, total time spend in womb or nursing is proportional to body size

What does vary between metatherians and eutherians

time spent in gestation vs lactation

What might be an advantage of long lactation time

Realativly easy to abandon young if conditions turn unfavorable.

mammogenesis

Preparation of mammary glands

Early lactogenesis

Period when young are attached to teat

Late lactogenesis

After young have detatched from teat

Eutherians milk conposistion

Remains fairly uniform

Metatherians milk composistion

Changes during lactation, often during early to late lactogenesis

What is the Estrous ccle

the time between entries into heat

Are mammals monoestrous or polyestrous

They can be both.

Do all mammals experiance a menstural cycle

No, if the egg is not fertilized, then it is reabsorbed in many

Phases of estrous cycle

Estrus (ovulation), metaestrous, diestrus, proestrus

What happens if an egg is fertalized

the female will enter into pregnancy, which may be a traditional, or slow pregnancy

Slow pregnancy

A pregnancy that is delayed, or even paused for periods of time. could result from unfavorable environmental factors.

Diapause

Form of sperm storage, or a fertalized egg that is paused in development

Induced ovulation

Dont frequently come in contact with males

Spontaneous ovulation

Can predictably come in contact with males

What happens in a delayed fertilizaiton

Copulation occurs, but ovulation is delayed (bats)

What happens in delayed implemtation

The pause occurs between fertilization and implatation

What happens in delayed development

Implation occurs, but gestation is delayed

How many joeys can a kangaroo have at once

3