| A | B |
|---|
| locus | a genes specific location along the lenghth of a chromosome |
| A sexual reproduction | A single individual is the sole parent and passes copies of all its genes on to its offspring |
| clone | a group of genetically identical individuals |
| sexual reproduction | 2 parents give rise to offspring that have unique combinations of genes inherited from the 2 parents |
| life cycle | is the generation 2 generation sequence of stages in the reproductive history of an organism, from conception to produeits own offspring |
| somatic cell | any cell other than a sperm or ovum has 46 chromosomes |
| karyotype | when the chromosomes are arranged in pairs starting with the longest ones |
| homologous chromosomes | the chromosomes that make up a pair that have the same length centromere position and staining pattern |
| autosomes | beside sex chromosomes |
| gametes | reproductive cells |
| fertilization | union of gametes |
| haploid cell | a cell with a single chromosome set |
| diploid cells | the zygote and all other cells having 2 sets of chromosomes |
| meiosis | sexually reproducing organisms carry out a process that halves th chromosome number in gametes compensating 4 the doubling that occurs in fertilization. |
| alternate generations | exhibited by plants a 3rd life cycle includes both diploid and haploid multi cellular stages |
| sporophyte | the multicellular diploid stage |
| spores | meiosis in the sporophyte produces haploid cells |
| gametophyte | a spore divides mitotically to generate a multicellular haploid stage |
| meiosis1 and2 | these divisions result in4 daughter cells rather than 2 in mitosis each with only half as many chromosomes as the parent |
| synapsis | during prophase of meiosis the duplicated chromosomes pair with thier homologues |
| terad | when the 4 closely associated chromatids of a homologous pair are visible in the light microscope |
| chiasmata | also visible in the light microscope are x shaped regions representing a crossing of nonsister chromatids |
| nonsister chromatids | 2 chromatids belonging 2 a seperate but homologos chromosome |
| meiosis 2 | seperates sister chromatids and is virtually identical 2 mitosis |
| crossing over | produces individual chromosomes that combine genes inherited from our 2 parents |
