Exam 6 Material (Deuterostomes)

Question 1

What kind of cleavage do deuterostomes have?

Answer 1

Radial indeterminant cleavage (when cells divide, they stack on top of each other, NOT in a spiral manner, they have the possibility to become anything/turn into a whole new animal)

Question 2

How do deuterostomes get their name?

Answer 2

B/c the second opening is the mouth (the blastopore—very first opening) when it start to fold into itself during gestralastion; becomes the anus

Question 3

What feature is important for deuterostomes?

Answer 3

Pharyngeal gill slits

Question 4

What is being described?:
- Basically the throat region
- Between the mouth and digestive tract
- Not present in present echinoderms, but they are present in extinct echinoderms/were secondarily lost
- the slits are separations between grooves or spaces
- Earlier it helped w/ digestion/suspension feeding
- Currently, it’s helpful for gas exchange
- Eventually became jaws in vertebrates

Answer 4

Pharyngeal slits

Question 5

Do deuterostomes have a coelom (space completely lined w/ mesoderm)?

Answer 5

Yes