13. Mammals

Question 1

Mamaliformes

Answer 1

The clade their containts the creown group mammals and the extinct relatives.

Question 2

Crown mammals consist of three clades

Answer 2

Prototheria - Monotremata (fx næbdyr)

Metatheria - Marsupialia (fx cangaroo)

Eutheria - Placentals (All the other mammals)

Question 3

Key characteristics of the crown group mammals

Answer 3

Hair
Endothermy and homeothermy
Sweat glands
Milk, modified sweatglands
Placenta
Pinnae, fleshy external ears
Middle ear bones
specializatopn of teeth
Soft palate
Neocortex

Question 4

Special function of hair

Answer 4

Filter

Fealing

Sexual

Protection - horns, spikes and plates are made of hair.

Question 5

Why is its smart to have endothermy

Answer 5

Then you can be active at night because you produce the heat internally.

It makes it possible for fx the polar bear to live at the arctics. Ectothermic animals can´t live at the arctic, because the lack of sun and cold temperatures.

Question 6

Why is the placenta smart?

Answer 6

While the young are developing it´s kept safe in the stomach of the mother. That´s very smart because the young is relly vulnerable in the beginning.

Question 7

Pinnae

Answer 7

Fleshy external ears, make some mammals hear better than other vertebrates.

Question 8

Exceptions

Answer 8

Some mammals lay egg, som have internal ears and others have to penisses

Question 9

Specialization of teeth, different types

Answer 9

Teeth do different jobs

Plant-eating animals have big molar teeth which have a big surface to grind the plants.

The canine teeth are used for catching things and holding on.

The holes make it able to filter water out and keep prey inside.

Question 10

What is the different type of teeth called?

Answer 10

Monophydonty, have their teeth for life.

Some mammals replace their teeth, diphydonty.

Polyphydonty, they can grow teeth throughout their entire lives.

Question 11

What is smart about the soft palate?

Answer 11

It allows you to eat and breath at the same time.

Question 12

The neocortex and why we may be less smart then birds.

Answer 12

Neocortex process sensory.

In humans - 80% of the brain volume is neocortex.

This doesn´t mean that we are more intelligent then other clades.

Ex of different smart animals, birds. A bassin where birds cant reach the food in a bowl of water, but there i some stones, which they use to raise the water level