Data

Copy and paste the text below. It is read-only. Select All

what is a distinctive association of signs and symptoms occurring together syndrome what is defined as the genetic composition genotype what is the observable appearance (physical, biochemical, physiologic traits) phenotype what are the hereditary units transmitted from one generation to another genes where are genes found? chromosomes (46 in human body) where are the chromosomes located? cell nucleus what do chromosomes contain? DNA DNA directs the production of _____ ____, ________ and ______ by the cell amino acids polypeptides proteins t/f DNA has the ability to duplicate itself true ______ is cellular division of somatic mitosis t/f after mitosis cells receive half the number of chromosomes as the original cells false (exact SAME number of chromosomes) what are the four stages of mitosis? prophase metaphase anaphase telophase what is two step cell division of sex cells? meiosis how many chromosomes does a cell have after meiosis? half the number what are the nonsex cells in the body called? somatic cells which cells in the body are the somatic cells? All of them except the ova and spermatozoa what is the process of cellular division in a SOMATIC CELL? what is this part of the cells life span called? mitosis mitotic cycle when is the gap1 phase? after cell division is complete what follows gap 1 phase? S phase during what phase of the mitotic cycle does replication of DNA take place S phase what follows S phase? gap 2 when does gap2 phase end? when mitotic division takes place what is the sequence of the mitotic cycle? mitotic division gap1 phase S phase gap2 phase mitotic division during which phase do the chromosomes line up? prophase where do the long (q) and short (p) arm join? centromere what is half the chromosome called? chromatid what phase are the chromosomes at the equatorial plan of the cell? metaphase which phase is it when chromatids are in the process of splitting? anaphase what phase is it when cytokinesis occurs? telophase what is cytokinesis splitting how does a cell become a mature germ cell? reduce their chromosome number by HALF how many chromosomes does a perimitive germ cell have? 2 for each pair what is a primitive germ cell called? diploid (46 chromosomes) what is a mature germ cell also known as? gametes what is the term for a gamete? haploid (23 chromosomes) how many chromosomes does a gamete have? 23 t/f the meiosis process maintains the normal number of human chromosomes at 46 true t/f meiosis is a three step process of cell division false (two step) what is it called when members of each pair of chromosomes line up and exchange segments and make contact? chiasmata (xshaped) what is it called when chromosomes that were crossing over do not separate and both migrate to the same cell nondisjunction what does nondisjunction cause? down syndrome what is down syndrome also called? trisomy 21 when does female oogenesis occur? third month of prenatal life what happens to the chromosome during second meiosis? splits longitudinally t/f no replication of DNA occurs after first meiosis FALSE (none occurs BEFORE the SECOND meiosis) what is it called when the genetic activity of one of the X chromosomes in each cell of a female embryo is inactivated? lyon hypothesis when does lyon hypothesis occur? early period of EMBRYONIC DEVELOPMENT what is the inactivated chromosome that forms a contracted structure known as? barr body how many strands does DNA have? RNA? DNA=double strand RNA=single strand what carries the genetic information? DNA DNA contains the _____ _____ or template that carries all the ______ information basic code genetic information what contains the DNA? chromosomes what is the basic unit of DNA? nucleotide what is the nucleotide formed by? (5) nitrogen containing base 5 carbon sugar (deoxyribose) phosphate what are the four bases of DNA? adenine guanine thymine cytosine A/___ and G/____ form the double helix A/T G/C what is coupled with adenine in DNA? thymine what is coupled with guanine? cytosine what is coupled with cytosine guanine what is coupled with thymine? adenine what are the four nitrogen bases for DNA? adenine thymine cytosine guanine what is a sequence of three bases called? codon the bases from chains that are coiled to form what? double helix what codes for amino acid? codon what do several amino acids form? polypeptide what do one or more polypeptides form? protein how is mitochondrail DNA inherited? maternally inherited the genetic code contained in DNA is transcribed into _____ to make ____ _____, _____ and _____ RNA amino acid polypeptides protein how many strands does RNA have? single strand what is the sugar for RNA? ribose (rather than deoxyribose for DNA) what replaces the base thymine in the RNA strand? uracil what is adenine coupled with in RNA? uracil what is cytocine coupled with in RNA? guanine (same as DNA) what type of RNA caries the transcription (blue print for coding proteins) messenger (mRNA) what type of RNA positions amino acids to form polypeptides transfer (tRNA) what RNA combines with several polypeptides to form ribosomes ribosomal (rRNA) what is the precursor to mRNA? heterogenous (hnRNA) what are the four types of RNA? mRNA tRNA rRNA hnRNA