LAB 4. Animal Development; Experimental Design

Question 1

gamete

Answer 1

a reproductive cell of an animal or plant

Question 2

zygote

Answer 2

fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm)

Question 3

blastopore

Answer 3

the opening by which the cavity of the gastrula, an embryonic stage in animal development, communicates with the exterior.

Question 4

triploblastic

Answer 4

a condition of the gastrula in which there are three primary germ layers: the ectoderm, mesoderm, and endoderm

Question 5

fertilization membrane

Answer 5

a resistant membranous layer in eggs of many animals that forms following fertilization by the thickening and separation of the vitelline membrane from the cell surface and that prevents multiple fertilization

Question 6

cleavage

Answer 6

a series of mitotic divisions whereby the enormous volume of egg cytoplasm is divided into numerous smaller, nucleated cells.

Question 7

blastula

Answer 7

hollow sphere of cells, or blastomeres, produced during the development of an embryo by repeated cleavage of a fertilized egg.

Question 8

blastocoel

Answer 8

a fluid filled cavity that is formed during the blastulation stage of embryo development and forms blastula

Question 9

protostome

Answer 9

They have spiral determinate cleavage, a mouth that develops before the anus in embryos, true tissues, and are bilaterally symmetric. Protostomia is Greek for first mouth, meaning that the mouth develops first in protostomes.

Question 10

fertilization

Answer 10

fertilization, union of a sperm nucleus, of paternal origin, with an egg nucleus, of maternal origin, to form the primary nucleus of an embryo.

Question 11

gastrula

Answer 11

Gastrulation is defined as an early developmental process in which an embryo transforms from a one-dimensional layer of epithelial cells (blastula) and reorganizes into a multilayered and multidimensional structure called the gastrula

Question 12

gastrulation

Answer 12

Gastrulation is defined as an early developmental process in which an embryo transforms from a one-dimensional layer of epithelial cells (blastula) and reorganizes into a multilayered and multidimensional structure called the gastrula.

Question 13

blastomere

Answer 13

a cell produced during cleavage of a fertilized egg

Question 14

deuterostome

Answer 14

“Deuterostome” the word means “second mouth”. It is a superphylum of kingdom Animalia grouping together all the animals having bilateral symmetry and the blastopore (the first opening in cleavage) developing into the anus during embryonic development. They include Echinodermata and Chordata.

Question 15

bipinnaria

Answer 15

the first larval stage in developing as a starfish

Question 16

archenteron

Answer 16

a cavity within an animal embryo

Question 17

germ layers

Answer 17

a group of cells in an embryo

Question 18

endoderm

Answer 18

the innermost of the three primary germ layers of an embryo that is the source of the epithelium of the digestive tract and its derivatives and of the lower respiratory tract.

Question 19

mesoderm

Answer 19

s a germ layer that arises during gastrulation, and is present between the ectoderm, which will turn into skin and central nervous system cells, and the endoderm, which will produce the gut and the lungs

Question 20

ectoderm

Answer 20

the outer layer of cells of a two-layered animal

Question 21

brachiolaria

Answer 21

The second stage of larval development in many sea stars, following the bipinnaria.

Question 22

coelom

Answer 22

the fluid-filled body cavity of an animal that contains the internal organs

Question 23

coelomate

Answer 23

have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm (one of the three primary tissue layers).

Question 24

acoelomate

Answer 24

an invertebrate lacking a coelom

Question 25

pseudocoelomate

Answer 25

organisms that have false body cavities