Unit 1

expression of different sets of genes in cells with the same genome; responsible for creating different cell types

any segment of DNA or RNA that is involved in controlling the expression of a specific gene by binding a regulatory transcription factor protein or other protein that regulates gene expression

general term for a protein that binds to a DNA regulatory sequence to influence transcription; includes both regulatory and general

a short nucleotide sequence in DNA that binds a sigma factor (bacteria) or basal transcription factor (eukaryotes) to enable RNA polymerase to begin transcription

a regulatory sequence in eukaryotic DNA that may be located far from the gene it controls or within introns of the gene; binding of specific regulatory transcription factor proteins enhances transcription of certain genes

large complex of proteins in eukaryotes that creates a physical link between regulatory transcription factors that are bound to DNA, general transcription factors, and RNA polymerase

protein that binds to a DNA regulatory sequence to increase the frequency of transcription initiation by RNA polymerase

regulatory sequence in eukaryotic DNA to which repressor proteins can bind, inhibiting gene transcription

a protein that binds to a silencer sequence in DNA to prevent or reduce gene transcription

in animals, the series of rapid mitotic divisions, with little cell growth, that produces successively smaller cells (blastomeres) and transforms a zygote into a multicellular blastula

a ball of cells (blastomeres) formed by cleavage of a zygote and typically containing a fluid-filled cavity (blastocoel)

the process of coordinated cell shape changes and movements, including the movement of some cells from the outer surface of the embryo to the interior that results in the formation of 3 germ layers (endoderm, mesoderm, ectoderm) and establishes the axes of the embryo

stage of embryonic development that follows the blastula during which 3 distinct germ layers form and the anterior-posterior and dorsal-ventral axes are established

the outermost of the 3 basic germ layers in most animal embryos that gives rise to the outer covering and nervous system

the innermost of the 3 basic germ layers in most animal embryos that gives rise to the digestive tract and organs that connect to it (liver, lungs, etc.)

the middle of the 3 basic germ layers in most animal embryos that gives rise to muscles, bones, blood, and some internal organs (kidney, spleen, etc.)

blocks of mesoderm that occur in pairs along both sides of the developing neural tube in a vertebrate embryo; gives rise to muscle, vertebrae, ribs, and the dermis of the skin

an animal tissue consisting of nerve cells (neurons) and various supporting cells

an animal tissue consisting of bundles of long, thin, contractile cells; functions primarily in movement

an animal tissue consisting of sheetlike layers of tightly packed cells that line an organ, gland, duct, or a body surface

an animal tissue consisting of loosely arranged cells in a liquid, jellylike, or solid extracellular matrix; includes bone, cartilage, tendons, ligaments, and blood

a group of tissues organized into a functional and structural unit

a group of tissues and organs that work together to perform a function

toward the base; in plants, toward the root or at base of branch where it joins the stem; in animals, on the side of an epithelial layer that abuts underlying body tissues

toward the top; in plants, at the tip of a branch; in animals, on the side of an epithelial layer that faces the environment and not other body tissues

a multicellular structure that extends from the base of an embryo and transfers nutrients from endosperm to the developing embryo

the first leaf, or seed leaf, of a plant embryo; used for storing and digesting nutrients and/or for early photosynthesis

the stem of a very young plant; the region between the cotyledon (embryonic leaf) and the radicle (embryonic root)

the root of a plant embryo

a group of undifferentiated cells at the tip of a plant stem; cells divide to produce new cells that can differentiate into mature shoot tissues

a group of undifferentiated cells at the tip of a plant root; cells divide to produce new cells that differentiate into mature root tissue

an embryonic tissue layer forming the outer layer of a plant

an embryonic tissue layer that gives rise to parenchyma, collenchyma, and sclerenchyma; tissues other than the dermal and vascular tissue

an embryonic tissue layer that transports water, nutrients, and sugars; made of of the complex tissues xylem and phloem, each of which contains several cell types

a group of undifferentiated plant stem cells that can give rise to the 4 organs making up a flower

a mutation that causes one body part of be substituted for another

a circular arrangement

one of the protective leaflike organs enclosing a flower bud and, after blooming, the outermost portion of the flower; expressed in gene A

any of the leaflike organs arranged around the reproductive organs of a flower; often the color and scent attract pollinators; expressed in gene A + B

one of the leaflike organs consisting of an anther, in which pollen grains are produced, and a filament, which supports the anther; expressed in gene B + C

one of the leaflike organs in a flower consisting of the stigma, to which pollen grains adhere; the style, through which the pollen tube grows; and the ovary, which houses the ovule; expressed in gene C

the gradual process by which the developmental fate of an embryonic cell is specified, directing it to become a particular type of a specialized cell; reversible in early stages

the final stage of commitment when an animal embryonic cell is locked into forming a particular type of specialized cell; typically irreversible and occurs before differentiation; not observed in plant cells

a molecule that exists in a concentration gradient and provides spatial information to embryonic cells

the process by which an unspecialized cell becomes a distinct specialized cell type (liver cell, brain cell) usually by changes in gene expression

a class of genes found in most animal phyla (including vertebrates) that are expressed in a distinctive pattern along the anterior-posterior axis in early embryos and control formation of specific structures; code for transcription factors with a DNA-binding sequence called a homeobox