embyonic origins

Question 1

3 embryonic germ layers and where they are in the embryo

Answer 1

1. ectoderm - outermost layer, generally gives rise to epidermis etc
2. endoderm - innermost layer, gives rise to linings of several organs
3. mesoderm - midlayer, gives rise to things such as bones and muscles

Question 2

three main categories of ectoderm:

Answer 2

1. Somatic (epidermal) ectoderm
2. Neural plate ectoderm
3. Neural crest ectoderm

Question 3

main category of endoderm:

Answer 3

lining of archanteron

Question 4

4 main categories of mesoderm:

Answer 4

1. Notochord
2. Epimere (somites)
3. Mesomere
4. Hypomere

Question 5

Somatic (epidermal) ectoderm gives rise to

Answer 5

Epidermis

Lining of mouth (anterior)

Olfactory opening

Cloacal opening

Question 6

Neural plate ectoderm gives rise to

Answer 6

Central nervous system (including brain, spinal chord)

Part of the eyes

Question 7

Neural crest ectoderm gives rise to:

Answer 7

Peripheral nervous system

Splanchnocranium

Parts of the chondocranium

Teeth in part

Question 8

The lining of the archanteron gives rise to:

Answer 8

Lining of the digestive tract

Posterior lining of the mouth

Liver and gallbladder

Pancreas

Trachea and lungs

Urinary bladder

Cloaca (in part)

Question 9

The notochord gives rise to

Answer 9

The notochord! lost during development for many taxa

Question 10

The epimere (somites) give rise to:

Answer 10

Dermatome - Dermis

Sclerotome - vertebrae and ribs

Myotome - most skeletal muscles

Question 11

Mesomere gives rise to:

Answer 11

Kidney

Urogenital ducts (most)

Question 12

hypomere gives rise to:

Answer 12

Somatic hypomere mesoderm

Splanchnic hypomere mesoderm

Question 13

somatic hypomere mesoderm gives rise to:

Answer 13

appendicular skeleton (except dermal bones)

peritoneum

gonads (in part)

Question 14

splanchnic hypomere mesoderm gives rise to:

Answer 14

Heart/vessels

smooth muscle of the digestive tract