| Term | Definition |
|---|
| histones | proteins called ____ are responsible for the first level of DNA packing in chromoatin |
| nucleosome | each "bead" is a _________, the basic unit of DNA packing |
| heterochromatin | non-transcribed eukaryotic chromatin that is so highly compacted that it's visible with a light microscope |
| euchromatin | the more open, unraveled form of eukaryotic chromatin that is available for transcription |
| cell differentiation | during development of a multicellular organism, its cells undergo a process of specialization in form and function called _____ _________, resulting in several or many differentiated cell types |
| histone acetylateion | in __________ _________, acetyl groups (--COCH3) are attached to positively charged lysines in histone tails |
| histone deacetylation | the removal of acetyl groups |
| genomic imprinting | a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent |
| epigenetic inheritance | inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence is called __________ _________ |
| control elements | segments of non-coding DNA that help regulate transcription by binding to certain proteins |
| transcription factors | to initiate transcription, eukaryotic RNA polymerase requires the assistance of proteins called _________ _________ |
| enhancers | the more distance distal control elements, groups of which are called ________, may be thousands of nucleotides upstream or downstream of a gene or even within an intron |
| activator | an __________ is a protein that binds to an enhancer and stimulates transcription of a gene |
| repressors | some specific transcription factors function as _________ to inhibit expression of a particular gene |
| micro RNAs | researchers have found small single-stranded RNA molecules, called ______ ______ (miRNAs), that can bind to complementary sequences in mRNA molecules |
| RNA interference | (RNAi)a technique to silence the expression of selected genes in non-mammalian organisims |
| small interfering RNAs | (siRNAs) Rna of similar size and function as miRNAs |
| proteasomes | giant protein complexes called _________ can recognize the ubiquitin-tagged protein molecules and degrade them |
| oncogenes | research on tumor viruses led to the discovery of cancer-causing genes called ___________ in certain retroviruses |
| proto-oncogenes | the normal cellular genes, _______-__________, code for proteins that stimulatae normal cell growth and division |
| tumor-suppressor gene | a gene whose protein products inhibit cell division, thereby preventing uncontrolled cell growth (cancer) |
| repetitive DNA | most intergenic DNA is ________ ______, sequences that are present in multiple copies in the genome |
| transposons; retrotransposons | eukaryotic transposable elemetsn are of two types: ________, which move within a genome by means of a DNA intermediate, and _______________, which move by means of an RNA intermediate |
| multigene families | collections of identical or very similar genes |
| pseudogenes | non-functional nucleotide sequences quite similar to the functional genes |
Combine with other sets
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