Campbell Chapter 21

Front 1

differentiation

Back 1

The structural and functional divergence of cells as they become specialized during a multicellular organism's development; dependent on the control of gene expression.

Front 2

morphogeneis

Back 2

The development of body shape and organization during ontogeny.

Front 3

apical meristems

Back 3

Embryonic plant tissue in the tips of roots and in the buds of shoots that supplies cells for the plant to grow in length.

Front 4

model organism

Back 4

An organism chosen to study broad biological principles.

Front 5

cell lineage

Back 5

The ancestry of a cell.

Front 6

cloning

Back 6

Using a somatic cell from a multicellular organism to make one or more genetically identical individuals.

Front 7

clone

Back 7

(1) A lineage of genetically identical individuals or cells

Front 8

stem cells

Back 8

In the bone marrow, a type of cell that gives rise to all the types of blood cells.

Front 9

determination

Back 9

The progressive restriction of developmental potential, causing the possible fate of each cell to become more limited as the embryo develops

Front 10

cytoplasmic determinant

Back 10

The maternal substances in the egg that influences the course of early development by regulating the expression of genes that affect the developmental fate of cell

Front 11

induction

Back 11

The ability of one group of embryonic cells to influence the development of another.

Front 12

pattern formation

Back 12

The ordering of cells into specific three-dimensional structures, an essential part of shaping an organism and its individual parts during development.

Front 13

positional information

Back 13

Signals to which genes regulating development respond, indicating a cell's location relative to other cells in an embryonic structure.

Front 14

egg polarity genes

Back 14

Another name for maternal effect genes, these genes control the orientation (polarity) of the egg.

Front 15

morphogens

Back 15

A substance, such as bicoid protein, that provides positional information in the form of a concentration gradient along an embryonic axis

Front 16

maternal effect genes

Back 16

A gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of the genotype.

Front 17

segmentation genes

Back 17

The genes of the embryo that direct the actual formation of segments after the embryo's axes are defined.

Front 18

gap genes

Back 18

Mutations in these genes cause "gaps" in Drosophila segmentation. The normal gene products map out the basic subdivisions along the anterior-posterior axis of the embryo.

Front 19

pair rule genes

Back 19

Genes that define the modular patterns in terms of pairs of segments in Drosophila. Mutations in these genes result in embryos with half the normal segment number because every other segment fails to develop.

Front 20

segment polarity genes

Back 20

Genes that set the anterior-posterior axis of each segment in Drosophila.

Front 21

homeotic genes

Back 21

Any of the genes that control the overall body plan of animals by controlling the developmental fate of groups of cells.

Front 22

homeobox

Back 22

A 180-nucleotide sequence within a homeotic gene encoding the part of the protein that binds to the DNA of the genes regulated by the protein.

Front 23

apoptosis

Back 23

Programmed cell death brought about by signals that trigger the activation of a cascade of "suicide" proteins in the cells destined to die.

Front 24

chimeras

Back 24

organisms with a mix of genetically different cells

Front 25

organ identity gene

Back 25

A plant gene in which a mutation causes a floral organ to develop in the wrong location.