lecture, slide 6, development

Question 1

embryonic development cycle

Answer 1

Question 2

a fertilized egg is also called a

Answer 2

zygote

Question 3

gamete formation is

Answer 3

the maturation and forming of sperm and egg

Question 4

define cleavage

Answer 4

rapid cellular growth, that leads to a multicellular embryo

after cleavage has produced about 100 cells the embryo is referred to as a blastula

an embryo transforms from a one-dimensional layer of epithelial cells, a blastula, and reorganizes into a multilayered and multidimensional structure called the gastrula

Question 5

define gasturaltion

Answer 5

germ layers form as embryo develops

Question 6

define organogenesis

Answer 6

the formation of body organs and differing cells with differing functions

Question 7

define blastocoel

Answer 7

fluid filled cavity

Question 8

gastrulation cycle

Answer 8

• blastocoel
• blastula
• gastrulation occurs
• early gastrula
• late gastrula

Question 9

what do germ layers do

Answer 9

each germ layer produces certain tissues or cells during embryonic development, germ layers will develop into all other tissues, organs, and so on

Question 10

what are the names of the germ layers

Answer 10

The three germ layers are the endoderm, the ectoderm, and the mesoderm

Question 11

the invagination of a gastrocoel (archenteron; center pouch) forms the

Answer 11

forms the gut cavity and blastopore (single opening)

Question 12

what is the ectoderm

Answer 12

one of the germ layers responsible for the formation of things such as skin and the nervous system

Question 13

what is the endoderm

Answer 13

one of the germ layers responsible for the formation of the digestive system

Question 14

what is the mesoderm

Answer 14

one of the germ layers responsible for the formation of muscles, circulatory systems, urogenital systems

Question 15

difference between diploblastic and triploblastic

Answer 15

diploblastic animals only contain the ectoderm and endoderm (sponges and cnidarians)

while triploblastic animals (all other animals) contain the ectoderm, mesoderm, and endoderm

Question 16

define hox genes

Answer 16

Doesn’t code for parts, but will specify locations for parts to develop along anterior-posterior axis

Activate or block other genes involved in development

Question 17

define triploblastic

Answer 17

having a body derived from 3 germ layers (ectoderm, mesoderm, endoderm)

Question 18

With protostomes (an organism who’s mouth develops from a primary opening such as worms), the blastopore becomes the _______

Answer 18

mouth

Question 19

with deuterostomes (organisms who’s first/primary opening is the anus), the blastopore becomes the _________

Answer 19

anus