Chapter 1

Question 1

Primary germ layers

Answer 1

Ectoderm
Mesoderm
Endoderm

Question 2

Embryogenesis

Answer 2

Stages of development b/w fertilization and hatching (birth)

Question 3

Blastopore

Answer 3

Dimple expands to a ring (mesoderm)

-during Gastrulation

Question 4

6 processes of embryogenesis

Answer 4

Fertilization, cleavage, gastrulation, organogenesis, metamorphosis, & gametogenesis

Question 5

Fertilization

Answer 5

Involves fusion of the mature sex cells, sperm & egg (gametes)

Question 6

Cleavage

Answer 6

Series of extreme rapid mitotic divisions immediately after fertilization

Question 7

Blastomeres

Answer 7

Enormous volume of zygote cytoplasm divided into numerous mini cells
[during cleavage]

Question 8

Blastula

Answer 8

Blastomeres formed a sphere

[end of cleavage]

Question 9

Gastrulation

Answer 9

• Mitotic rate slows down & blastomeres undergo dramatic movements & change their position
• three germ layers: results

Question 10

Organogenesis

Answer 10

Once germ layers are established, cells interact w/ one another and rearrange themselves to prod. tissues and organs
[migrating cells, precursor blood, lymph, pigment, gamete cells]

Question 11

Metamorphosis

Answer 11

Change an organism goes through to become a sexually mature adult
-germ cells

Question 12

Gametogenesis

Answer 12

Development of gametes, not complete untill maturity

Question 13

Blastocoel

Answer 13

Fluid filled cavity in animal pole. Important for allowing cell movements to occur during gastrulation

Question 14

Notochord

Answer 14

• Where organogenesis begins

- Rod of mesodermal cells, signals ectodermal cells above to form tube

Question 15

Neurula

Answer 15

Stage in which embryo formed a tube and have CNS

Question 16

Neural tube

Answer 16

Future epidermal cells of back

Question 17

Somites

Answer 17

Mesodermal tissue adjacent to the neural tube & notochord becomes segmented
-muscle, vertebrae, dermis

Question 18

Fertilization & egg activation

Answer 18

Gray crescent (cortie cytoplasm shifts)

Question 19

Preformationism

Answer 19

The idea that organisms develop from miniature versions of themselves
Ex Leeuwenhoek, malpigni

Question 20

Epigenesis

Answer 20

The idea that animal development features an embryo thats influenced by external and internal environment, forms structure not present in gametes
Ex wolff

Question 21

Recapitulation

Answer 21

Ontongeny (dev) recapitulates phylogeny (history)

Ex Haeckel