Embryonic Development - Day 10 Flashcards
What happens ten fays after fertilisation?
The cells of the inner cell mass of the blastocyst form three layers of cells called primary germ layers
Name the three primary germ layers?
Ectoderm
Mesoderm
Endoderm
Define germ layers.
Germ layers are basic layers of cells in the blastocyst from which all adult tissues and organs will form
What forms the germ layers?
The cells of the inner cell mass of the blastocyst
When are the germ layers developed?
They are developed about ten days after fertilisation
Describe the structure of the mesoderm (middle layer of cells) in humans
(2)
It is divided into an outer and inner layer
The gap between them is called a coelom and it allows space for complex organs such as the heart, lungs and kidneys to develop
Which of the three germ layers forms the coelom?
The mesoderm (middle layer)
What is the gap between the outer and inner layer of the mesoderm called?
The coelom
What is the coelom?
The gap between the outer and inner layers of the mesoderm
What is the function of the coelom?
It allows space for complex organs such as the heart, lungs and kidneys to develop
Which animals form more complex organ systems, those with two germ layers or those with three germ layers?
Those with three germ layers
Give an example of an animal which arises from three germ layers.
Humans
Give an example of an animal which arises from two germ layers
Jellyfish
Which germ layer is lacking in animals which arise from only two germ layers?
The mesoderm
What organs/systems are produced by the ectoderm?
4
Skin
Nails
Hair
Nervous system
