Question

difference between prototheria and eutheria

Answer 1

Prototheria are the types of mammals that lay eggs even though they use mammary glands to feed their young ones which lack nipples.e.gEchidna while eutheria which are also known as placental mammals are the infraclass of mammals that give live birth to the young ones.They carry their unborn child within the uterus and nourish it through placenta.They use mammary glands to feed their young ones with well developed nipples i.e cow

Answer 2

✌️✌️hey mate,

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➡️Prototheria:

1. They are OVIPAROUS.
2. Ear is devoid of pinna .
3. Scrotum is absent in male.
4. Vagina and uterus are absent.
5. Nipples are absent over the mammary gland.
e.g.,
•Echidna,
•Tachyglossus,
•Ornithorhnchus.

➡️Eutheria:
1. They are ViViPAROUS.
2. pinna is present except in aquatic forms.
3. the scrotum is present on the sides and behind the penis.
4. they are single structure.
5. nipples are present.


➡️Metatheria:
1. They are ViViPAROUS.
2. ear possess a pinna.
3. scrotum is present but infront of penis.
4. both vagina and uterus are double.
5. Nipples are present.

e.g.,
•Macropus,
•Didelphis.
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thanks...