Embryonic Development

Question 1

Describe what the bilaminar disc is (3mks)

Answer 1

2 layers formed of the epiblast layer (upper layer) and the hypoblast layer (lower layer)

Question 2

Define gastrulation

Answer 2

Where the epiblast layer starts to go inwards and form three layers called the ectoderm mesoderm and endoderm

Question 3

What are the three germ layers and what do they become? (6mks)

Answer 3

Endoderm becomes the endocrine system and digestive system etc
Mesoderm forms organs like the heart and muscle
Ectoderm forms the nervous system such as the brain and spinal cord

Question 4

Describe morphogenesis

Answer 4

Getting things organised and creating our shape

Question 5

Describe organogenesis

Answer 5

Forming and developing our systems and organs

Question 6

What is the upper layer of the bilaminar disc called? (1mk)

Answer 6

Epiblast

Question 7

What causes gastrulation? (2mks)

Answer 7

The epiblast cells forming a groove on the upper disc called a primitive streak

Question 8

What are 3 processes involved with morphogenesis? (3mks)

Answer 8

Tissue folding
Tube production
Cell migration