Deutrostomes (Deutro)

Question 1

What are deutrostomes a group of?

Answer 1

Metazoans –> means multicellular animals

Question 2

What are the phyla that are Metazoa?

Answer 2

• Calcarea and Silicea
• Cnidaria
  Protostomia:
• Lophotrochozoa
• Ecdysozoa
• Deuterostomia

Question 3

What are Eumetazoa?

Answer 3

They have 2 germ layers

Question 4

What are Bilateria?

Answer 4

• Bilateral symmetry
• Have 3 germ layers

Question 5

What are the 4 ways which Deutrostomes differentiate from Protostomes?

Answer 5

1 - In the way their cells cleave early on

2 - In the way their cells fate is determined

3 - In how they use their blastopore

4 - In the way they form their coelomic activity

Question 6

How are the members of the Deuterostomes grouped together?

Answer 6

It is revealed bysimilarities in their DNA sequence that reflect evolution from a common ancestor

Question 7

How does the embryo cleave in a protostome?

Answer 7

Spiral cleavage

Question 8

How does the embryo cleave in a deutrostome?

Answer 8

Radial cleavage

Question 9

What is spiral cleavage?

Answer 9

(How the protostome cleaves in a protostome)

The cleavage planes are diagonal to the vertical axis of the embryo

Question 10

What is radial cleavage?

Answer 10

(How the deutrostome cleaves in a protostome)

Cleavage planes are parallel or perpendicular to the vertical axis of the embryo

Question 11

What are the protostome embryos like in the second stage?

(Cell fate)

Answer 11

Most are mosaic

Question 12

What are the deutrostomes embryos like in the second stage?

(Cell fate)

Answer 12

Most are regulative

Question 13

What does it mean for protostome embryos to be mosaic?

Answer 13

• The developmental fate of every cell is largely PREDETERMINED/restricted
• Cleavages are said to be determinate

Question 14

What does it mean for deuterostome embryos to be regulative?

Answer 14

• The developmental fate of every cell is NOT yet DETERMINED –> every cell can give rise to a full organism (human identical twins)
• Cell cleavages are said to be indeterminate

Question 15

How does a blastula develop?

Answer 15

• The dividing cells first form a soling ball of cells, a morula
• Eventually a cavity develops & the ball becomes hollow - a blastula
• Eventually the blastula folds in on itself during gastrulation

Question 16

What are the stages of progression to form a blastula?

Answer 16

Zygote –> Morula –> Early Blastula –> Late Blastula

Question 17

What is it called whne the blastula folds in on itself during gastrulation?

Answer 17

It’s called a morphogenis (form-generating) movement

Question 18

What are the stages of an embryo (or blastula idk) forming in a protostome?

Answer 18

1. Spiral cleavage
2. Mosaic embryo
3. Blastopore becomes mouth, anus forms secondarily
4. Coelom forms by splitting (schizocoelous)

Question 19

What are the stages of an embryo (or blastula idk) forming in a deuterostome?

Answer 19

1. Raidal cleavage
2. Regulative embryo
3. Blastopore becomes anus, mouth forms secondarily
4. Coelom forms by outpocketing (enterocoelois)

Question 20

What is gastrulation?

Answer 20

The blastoder invaginates (it folds in) - forming the blastopore

Question 21

What forms during gastrulation?

(blastoderm)

Answer 21

The ectodermal (echo-outer), endodermal (endo-inner) and mesodermal (mesos-middle) germ layers

Question 22

What does the endoderm do during the formation of the blastopore?

Answer 22

Th endoderm lines the inner cavity - the ARCHENTERON

Question 23

What does the archenteron develop into?

Answer 23

The gut

Question 24

What is the openeing of the archenteron to the outside called?

Answer 24

This is the blastopore!!

The fate of the blastopore is different in Protostomes and Deuterostomes

Question 25

What does the blastopore form in Protostomes?

Answer 25

The mouth A second opening breaks through & forms the anus

Question 26

What does the blastopore form in Deuterostomes?

Answer 26

The blastopore develops into the anus The mouth breaks thru secodnarily

Question 27

What is the coelom?

Answer 27

It is a fliu-filled body cavity within the mesoderm (lined w mesoderm) It seperates the body wall from the digestive tract

Question 28

What it schizocoelous formation?

Answer 28

How the coelom within the mesoderm forms in Protostomes Within solid masses of mesodermal cells in many protostomes

Question 29

What is Enterocoelous formation?

Answer 29

How the coelom within the mesoderm forms in Deuterostomes As evaginatiion of the archenteron foor in many Deuterostomes

Question 30

What are the 3 layers in an embryo and how do they support growth?

Answer 30

- Ecotderm (outer layer) - Mesoderm (middle layer) - Endoder (internal layer) Each layer allows a different part of the organism to develop

Question 31

What does the ectoderm layer in an embryo form?

Answer 31

- Outer surface - CNS - Neural crest

Question 32

What does the mesoderm layer in an embryo form?

Answer 32

- Dorsal --> notochord - Paraxial --> bone tissue - Intermediate --> tubule cell of the kidney - Lateral --> RBCs - Head --> facial muscle

Question 33

What does the endoderm layer in an embryo form?

Answer 33

- Digestive tube - Pharynx - Respiratory tube

Question 34

What taxinomic rank is Hemichordata?

Answer 34

Phylum

Question 35

What are hemichordata?

Answer 35

Are marine animals who share soem similariteis w chordates (have gill slits)

Question 36

What is the body of hemichordata like?

Answer 36

Is tripartite - has 3 parts Each has 1 or 2 coelomic cavities seperated by septa

Question 37

Finsih from bottom of slide 17

Answer 37

Thank u