Post Lab Quiz #1

Question 1

Diploblastic Pattern

Answer 1

Two layers of germs in the embryo ( seen in Cnidaria)

Question 2

Triploblastic Pattern

Answer 2

Three layers of germs. (Endoderm, Mesoderm, and Ectoderm)

Question 3

Germ layer on the inside of the embryo

Answer 3

Endoderm

Question 4

Germ layer on the outside of the embryo

Answer 4

Ectoderm

Question 5

Layer that forms in the middle

Answer 5

Mesoderm

Question 6

Organogenesis

Answer 6

The cells of different germ layers interact with each other which leads to the development of tissues and organs

Question 7

Protostome Cleavage

Answer 7

Spiral; dividing blastomeres rest in the crevices of the other cells

Question 8

Deuterostome Cleavage

Answer 8

Radial; cells rest directly on top of other cells

Question 9

Pseudocoelomate

Answer 9

• coelom unlined with peritoneum
• No messentries
• Organs can twist

Question 10

Eucoelomate

Answer 10

• Coelom lined with peritoneum & mesentries

- Eucoelom and coelom present

Question 11

Hemocoel

Answer 11

• Blood cavity
• Coelom usually present
• Found in molluscs and arthropods

Question 12

Acoelomate

Answer 12

Has no body cavity

Question 13

2 cell stage

Answer 13

The zygote divides into two equal blastomeres

Question 14

Gastrula stage (spiral cleavage)

Answer 14

After cells form a hollow ball, the next division occurs and creates in indentation in one end of the ball.
-Creates a cavity called the gastrocoel

Question 15

Morula stage (spiral cleavage)

Answer 15

-16-32 cells

Division continues, embryo looks like a solid ball of cells

Question 16

Blastula stage (spiral cleavage)

Answer 16

• 64+ cells

- Divided to form a hollow ball of cells

Question 17

Homologous structures

Answer 17

-Diverged somewhat from their ancestral forms
similarity due to a common ancestor
-look similar but not the same function

Question 18

Analogous structures

Answer 18

-Same function but look different

Question 19

Divergent evolution

Answer 19

Groups from the same common ancestor develop new traits that make them into new species

Question 20

Convergent evolution

Answer 20

Development of similar traits due to the environment. Not from common ancestor

Question 21

Monophyletic group

Answer 21

A group of species descended from the most recent common ancestor and includes its ancestral population plus all of its descendents.

Question 22

Paraphyletic group

Answer 22

Includes the most recent common ancestor but not all of the descendents.

Question 23

Polyphyletic group

Answer 23

Does not contain the most common ancestor

-Group must have at least two separate ancestral origins