Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Exam 2 Dev. Bio.
vocab from Dr. Hoffman's studyguides
| Term | Definition |
|---|---|
| Syncitium | a cell with many nuclei in a common cytoplasm. Cell walls do not develop during nuclear division with the very early drosophila embryo. This gives rise to the syncytial blastoderm in which the nuclei are arranged around the periphery of the embryo. |
| Pole cells | gives rise to the germ cells in drosophila and are formed at the posterior end of the blastoderm. |
| Germ band | name given to the ventral blastoderm of the early drosphila embryo, from which most of the embryo will eventually form. |
| Segmentation | the division of the body of an organism along the antero-posterior axis into a series of morphologically similar units or segments. |
| Parasegments | in the developing drosophila embryo are independent developmental units that give rise to the segments of the larva and adult. |
| Acron | a specialized structure associated with the most anterior region of the Drosophila embryo. |
| Telson | a distinctive structure at the posterior end of the Drosophila embryo. |
| Denticles | small tooth-like outgrowths of the cuticle on insect larvae. |
| Instar | the phase between each molt of larva |
| Pupa | the stage following the larval stages in which the organism can remain dormant for long periods and in which metamorphosis occurs. |
| Metamorphosis | the process by which a larva is transformed into an adult. Involves a radical change in from and the development of new organs. |
| Imaginal discs | small sacs of epithelium present in the larva of Drosophila and other insects, which at metamorphosis give rise to adult structures such as wings, legs, antennae, eyes, and genitalia. |
| Maternal effect mutations | mutations in genes of the mother that affect the development of the egg and later the embryo. Genes affected by such genes are maternal effect genes. |
| Maternal factors | |
| Zygotic genes | those present in the fertilized egg and which are expressed in the embryo itself. |
| Threshold concentration | a concentration of a chemical signal or morphogen that can elicit a particular response froma cell. |
| Germplasm | a special cytoplasm in some animal eggs, such as those of Drosophila, that is involved in the specification of germ cells. |
| Dorsalized | embryos that are deficient in ventral regions and have much increased dorsal regions. |
| Ventralized | embryos that are deficient in dorsal regions and have much increased ventral regions. |
| Cell differentiation | cells become functionally and structurally different from one another and become distinct cell types. |
| transcription. | |
| activators. | |
| Transcription factors | a regulatory protein required to initiate or regulate the transcription of a gene into RNA. Transcription factors act within the nucleus of a cell by binding to specific regulatory regions in the DNA. |
| Repressors | gene regulatory proteins that act to suppress gene activity when they bind to specific sites in the gene control regions. |
| Tissue-specific | the expression of a gene only in a particular tissue or cell type. |
| Heterochromatin | the state of chromatin in which transcription of the DNA is not possible. Chromatin |
| Egg chamber | the structure within which an oocyte develops surrounded by its nurse cells and follicle cells. |
| Cytoplasmic bridge | thin strand of cytoplasm linking nurse cells and developing eggs or sperm cells. |
| Microtubule | one of the three principal protein filaments of the cytoskeleton. They are involved in the transport of proteins and RNAs within cells. |
| Cytoskeleton | the network of protein filaments – microfilament, microtubules, and intermediate filaments- that gives cells their shape, enables them to move, and provides tracks for transport of materials in the cell. |
| Segmentation genes | genes involved in patterning the parasegments and segments. |
| Selector genes | determine the activity of a group of cells, and their continues expression is required to maintain that activity. |
| Homeotic selector gene | genes that specify the identity and developmental pathway of a group of cells |
| Homeotic transformations | a result of mutation in a homeotic gene involving one structure transforming into another. |
| Hox genes | a family of homeobox-containing genes that are present in all animals and are involved in patterning the antero-posterior axis. |
| Homeobox | a region of DNA in homeotic genes that encodes a DNA-binding domain called the homeodomain. |
| Bithorax complex | comprises one part of the Hox gene complex in Drosophila. |
| Antennapedia complex | comprises on part of the Hox gene complex. |
| Co-linearity | the correspondence between the order of Hox genes on a chromosome and their temporal and spatial order of expression in the embryo. |
Created by:
1236956839
Popular Biology sets