what is a distinctive association of signs and symptoms occurring together
what is defined as the genetic composition
what is the observable appearance (physical, biochemical, physiologic traits)
what are the hereditary units transmitted from one generation to another
where are genes found?
chromosomes (46 in human body)
where are the chromosomes located?
what do chromosomes contain?
DNA directs the production of _____ ____, ________ and ______ by the cell
t/f DNA has the ability to duplicate itself
______ is cellular division of somatic
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?
what is two step cell division of sex cells?
how many chromosomes does a cell have after meiosis?
half the number
what are the nonsex cells in the body called?
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?
when is the gap1 phase?
after cell division is complete
what follows gap 1 phase?
during what phase of the mitotic cycle does replication of DNA take place
what follows S phase?
when does gap2 phase end?
when mitotic division takes place
what is the sequence of the mitotic cycle?
during which phase do the chromosomes line up?
where do the long (q) and short (p) arm join?
what is half the chromosome called?
what phase are the chromosomes at the equatorial plan of the cell?
which phase is it when chromatids are in the process of splitting?
what phase is it when cytokinesis occurs?
what is cytokinesis
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?
what is the term for a gamete?
haploid (23 chromosomes)
how many chromosomes does a gamete have?
t/f the meiosis process maintains the normal number of human chromosomes at 46
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?
what is it called when chromosomes that were crossing over do not separate and both migrate to the same cell
what does nondisjunction cause?
what is down syndrome also called?
when does female oogenesis occur?
third month of prenatal life
what happens to the chromosome during second meiosis?
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?
when does lyon hypothesis occur?
early period of EMBRYONIC DEVELOPMENT
what is the inactivated chromosome that forms a contracted structure known as?
how many strands does DNA have? RNA?
what carries the genetic information?
DNA contains the _____ _____ or template that carries all the ______ information
what contains the DNA?
what is the basic unit of DNA?
what is the nucleotide formed by? (5)
nitrogen containing base
5 carbon sugar (deoxyribose)
what are the four bases of DNA?
A/___ and G/____ form the double helix
what is coupled with adenine in DNA?
what is coupled with guanine?
what is coupled with cytosine
what is coupled with thymine?
what are the four nitrogen bases for DNA?
what is a sequence of three bases called?
the bases from chains that are coiled to form what?
what codes for amino acid?
what do several amino acids form?
what do one or more polypeptides form?
how is mitochondrail DNA inherited?
the genetic code contained in DNA is transcribed into _____ to make ____ _____, _____ and _____
how many strands does RNA have?
what is the sugar for RNA?
ribose (rather than deoxyribose for DNA)
what replaces the base thymine in the RNA strand?
what is adenine coupled with in RNA?
what is cytocine coupled with in RNA?
guanine (same as DNA)
what type of RNA caries the transcription (blue print for coding proteins)
what type of RNA positions amino acids to form polypeptides
what RNA combines with several polypeptides to form ribosomes
what is the precursor to mRNA?
what are the four types of RNA?