22 - Genetics of Development

Question 1

Zygote

Answer 1

The diploid cell produced by the union of haploid gametes during fertilization; a fertilized egg

Question 2

Blastula

Answer 2

A hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals

Question 3

Gastrula

Answer 3

An embryonic stage in animal development encompassing the formation of three layers; ectoderm, mesoderm, and endoderm

Question 4

Animal pole

Answer 4

The point at the end of an egg in the hemisphere where the least yolk is concentrated; opposite of vegetal pole

Question 5

Animal hemisphere

Answer 5

refers to the portion of an egg or embryo that contains the majority of the cytoplasm and typically less yolk

Question 6

Vegetal pole

Answer 6

The point at the end of an egg in the hemisphere where most yolk is concentrated; opposite of animal pole

Question 7

Vegetal hemisphere

Answer 7

refers to the portion of an egg or embryo that contains a higher concentration of yolk compared to the animal hemisphere

Question 8

Cytoplasmic determinant

Answer 8

A maternal substance, such as a protein or RNA, that when placed into an egg influences the course of early development by regulating the expression of genes that affect the developmental fate of cells

Question 9

Maternal determinant

Answer 9

are substances, such as proteins, RNAs, and other molecules, that are deposited in the egg by the mother during oogenesis (egg development).

Question 10

Blastomere

Answer 10

An early embryonic cell arising during the cleavage stage of an early embryo

Question 11

Blastocoel

Answer 11

The fluid-filled cavity that forms in the center of a blastula.

Question 12

Cell division

Answer 12

the reproduction of cells

Question 13

Cell differentiation

Answer 13

is the process by which a less specialized cell becomes a more specialized cell type

Question 14

Cell determination

Answer 14

is the process by which a cell becomes committed to a specific fate or function during development

Question 15

Master regulator

Answer 15

is a gene or protein that controls the expression of a large number of other genes, thereby orchestrating complex processes such as cell differentiation, development, or response to environmental changes

Question 16

Gastrulation

Answer 16

In animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three layered embryo, the gastrula.

Question 17

Morphogenesis

Answer 17

the development of the form of an organism and its structures

Question 18

Organogenesis

Answer 18

the process in which organ rudiments develop from the three germ layers after gastrulation

Question 19

Neurulation

Answer 19

is a crucial process in embryonic development during which the neural tube is formed

Question 20

Notocord

Answer 20

is a flexible, rod-shaped structure that plays a crucial role during the early development of vertebrates

Question 21

neural tube

Answer 21

A tube of infolded ectodermal cells that runs along the anterior-posterior axis of a vertebrate, just dorsal to the notochord. It will give rise to the central nervous system

Question 22

Ectoderm

Answer 22

The outermost of the three primary germ layers in animal embryos; gives rise to the outer covering and, in some phyla, the nervous system, inner ear, and lens of the eye.

Question 23

Endoderm

Answer 23

the innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract in species that have these strucutres.

Question 24

Mesoderm

Answer 24

The middle primary germ layer in a triploblastic animal embryo develops into notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system in species that have these structures

Question 25

Involution

Answer 25

refers to a specific type of cell movement that occurs during the process of gastrulation in embryonic development.

Question 26

Dorsal lip

Answer 26

the region above the blastopore on the dorsal side of the amphibian embryo

Question 27

Induction

Answer 27

a process in which a group of cells or tissues influences the development of another group through close range interactions

Question 28

Organizer

Answer 28

refers to a specific region of an embryo that has the ability to direct the development of surrounding tissues, effectively organizing the body plan of the developing organism.

Question 29

Bicoid

Answer 29

is a maternal effect gene that plays a crucial role in establishing the anterior-posterior axis in the early development of Drosophila melanogaster, commonly known as the fruit fly.

Question 30

Morphogen

Answer 30

a signaling molecule that governs the pattern of tissue development in the process of morphogenesis, and it helps to establish the spatial organization of cells.