Animal architecture, reproduction, development

Question 1

Anterior means what?

Answer 1

Head region

Question 2

Posterior?

Answer 2

Tail end

Question 3

Dorsal?

Answer 3

back or Upper side

Question 4

Ventral

Answer 4

belly or underside

Question 5

Medial

Answer 5

Midline

Question 6

Lateral

Answer 6

sides

Question 7

Distal

Answer 7

Further from middle, outside

Question 8

Proximal

Answer 8

closer to middle, inside

Question 9

Asymmetry

Answer 9

lack of equality or equivalency between parts

Question 10

Radial symmetry

Answer 10

Can be divided into similar halves by more than two planes passing through a longitudinal axis

Question 11

Bilateral symmetry

Answer 11

can be divided along a sagittal plane in two mirrored portions.

Question 12

oogenesis

Answer 12

meiosis that results in egg cells and occurs in the ovaries

Question 13

Spermatogenesis

Answer 13

meiosis that results in sperm cells and occurs in the testes.

Question 14

Isolecithal

Answer 14

very little egg yolk, evenly distributed throughout the egg. (most mammals echinoderms, annelids, molluscs)

Question 15

Mesolecithal

Answer 15

Moderate amount of egg yolk concentrated at ONE end of the egg (vegetal pole). (most amphibians)

Question 16

Telolecithal

Answer 16

Large amount of egg yolk, occupies most of the egg; embryo is confined to a small disk at the animal pole. (birds, reptiles, most fishes)

Question 17

Centrolecithal

Answer 17

large amount of egg yolkd, embryo forms a thin layer around the yolk mass (most arthropods)

Question 18

What is an animal pole?

Answer 18

in an unfertilized egg. The pole where the embryo will develop and be darker in color

Question 19

What is the vegetal pole?

Answer 19

in an unfertilized egg. The pole where the yolk is concentrated and be lighter in color

Question 20

What is a morula?

Answer 20

A morula is a cluster of cells with no cavity composed of16-32 totipotent cells

Question 21

What is a Blastula?

Answer 21

A blastula is a cluster of cells resulting from the cleavage of a zygote

Question 22

What is a Blastocoel?

Answer 22

A blastocoel is cells of a blastula arranged in a central fluid-filled cavity; primitive

Question 23

Name the three Germ layers formed in the early embryo

Answer 23

Ectoderm - outer embryonic layer
mesoderm - middle embryonic layer
Endoderm - inner embryonic layer
all three of these formed during late gastrulation

Question 24

What is a germ layer?

Answer 24

a layer of cells formed in the early embryo

Question 25

What is a Blastopore?

Answer 25

The opening to the gut at the beginning of gastrulation

Question 26

Archenteron (gastrocoel) what is it?

Answer 26

primitive gut that forms during gastrulation as the blastopore shrinks

Question 27

What is a Gastrula?

Answer 27

after blastulation, this forms when cells fold back on themselves to form a pouch and migrate to the center of the blastocoel

Question 28

Yolk plug (in amphibians)

Answer 28

remaining patch of endodermal cells that is created during the formation of the dorsal lip of blastopore

Question 29

Neural folds

Answer 29

enlarged ridges on the surface of the mid-dorsal region of the embryo because of neurulation

Question 30

Neural grooves

Answer 30

depression bordered by neural folds

Question 31

Notochord

Answer 31

cylindricalsection of mesodermal cells from the developing neural tube, eventually develops into vertebrae

Question 32

Sag ittal

Answer 32

divides from left to rig ht

Question 33

Midsagittal

Answer 33

– divides from right and left, directly in the middle

Question 34

Frontal (coronal)

Answer 34

divides body dorsally and ventrally

Question 35

Transverse (cross-section)

Answer 35

cuts at a right angle to both the sagittal and frontal planes and separates anterior and posterior

Question 36

what is Holoblastic cleavage? (1 of 2 main types)

Answer 36

complete cleavage of e g g

Question 37

what are the two subtypes of holoblastic cleavage?

Answer 37

Spiral - cleavage occurs at oblique angles AND Radial - cleavage planes are perpendicular and parallel to each other

Question 38

What is Meroblastic cleavage? (2 of 2 main types)

Answer 38

incomplete cleavage of e g g

Question 39

What are the 2 subtypes of meroblastic cleavage?

Answer 39

The two subtypes of meroblastic cleavage are; Discoidal - cleavage limited to one end of e g g AND Superficial- cleavage occurs only in the periphery of e g g