Question | Answer |
gene | segment of DNA that transmits info. from parent to offsring |
chromosome | rod shaped structure that forms when a single DNA molecule and its associated proteins coil tightly together before cell dividion |
chromatid | the 2 copies of each chromasome |
centromere | the point where the two chromatids are attached by a protein disk. |
homogolous chromosomes | chromosomes that are simular in size, shape and genes that they carry. |
diploid | cell containing two homologous of each chromosome |
gametes | egg cells and sperm cells |
haploid | cell contains only one homologue of each chromosome |
zygote | fertilized egg cell |
trisomy | condition in which adiploid cell has an extra chromosome |
karyotype | collection of chromosomes found in an individuals' cells |
Down syndrome | when an individual has an extra copy of chromosome 21 |
nondisjunction | accident in chromosome seperation when 1 daughter cell gets both chromosomes and the other daughter cell gets none |
amniocentesis | procedure where sample of amniotic fluid is drawn and tested for genetic abnormalities |
chorionic villi sampling | fetal testing procedure where pieces of chrionic villi in mom's uterus = removed and testes for abnormalities |
mutations | changes in organisms genetic material |
deletion | when a fragment of a cell breaks off and is lost when a cell divides |
duplication | form of mutation where the chromosome contains an extra copy of a segment of DNA |
inversion | mutation in which a chromosome fragment rejoins it's origional chromosome w/ its nucleotides reversed |
translocation | form of mutation caused by a chromosome fragment joining a nonhomologous chromosome during cell division |
autosomes | a chromosome not directly involved in determinating sex |
sex chromosomes | chromosomes that differ between males and females |