| A | B |
|---|
| A Syndrome | A condition with several unrelated symptoms with a common cause |
| What causes most syndromes? | Too much or too little genetic material |
| Which has more of an effect on heath, an excess or deficit of genetic material? | Deficit |
| Cytogenetics | Links chromosome variations to specific traits, including illnesses |
| Name two ways that the HGP has added to our knowledge of cytogenetics | 1. Identifying which genes contribute which symptoms to chromosome related syndromes 2. by comparing the gene contents of the chromosomes |
| Chromatin | Made of up two molecules: DNA and Proteins |
| Two types of chromatin | 1. Heterochromatin - junk DNA, stains darkly 2. Eurochromatin - more protein encoding genes stains lightly |
| List 3 parts of chromasome that enable REPLICATION | 1. Telomere 2. Centromere 3. Origin of replication sites |
| What is a TELOMERE? | Chromasome tip consisting of many repeats of the DNA sequence |
| What is a CENTROMERE? | Largest contriction of the chromosome |
| Metacentric chromosome | Centromere divides the chromosome into two arms of approx equal length |
| Submetacentric chromosome | Centromere divides chromosome into one long arm and one short arm |
| Acrocentric chromosome | Centromere pinches off only a small amount of material toward one end |
| Telocentric chromosome | Consists of only one arm (none in humans) |
| What are 4 ways chromosomes are distinguishable? | 1. Size 2. Presence of satellites |
| What do p and q indicate about a chromosome? | p = short arm; q = long arm |
| What is a KARYOTYPE? | A chart that displays homologous chromosome pairs by size; 22 autosomes, 1 pair of sex chromosomes |
| How are karyotypes useful? | 1. Can confirm clinical diagnosis 2. Can reveal effects of environmental toxins 3. Can clarify evolutionary relationships 4. Identify chromosomal abberations within a pedigree |
| What are 3 techniques for obtaining fetal cells from an unborn child? | 1. Amniocentesis 2. Chorionic Villi Sampling (CVS) 3. Fetal Cell Sorting |
| What are 3 types of information learned from a karyotype? | 1. Chromosome number 2. Sex chromosome constitution 3. Abnormal autosomes |
| What are two types of autosomal abberations observable from a karyotype? | Polyploidy, Aneuploidy |
| What is an IDEOGRAM? | A schematic chromosome map indicating chromosome arms, banding patterns and the loci of known genes |
| What 4 observations render a karyotype abnormal? | 1. Polyploidy 2. Aneuploidy 3. Deletions 4. Duplications |
| What is POLYPLOIDY? | A cell with one or more sets of chromosomes |
| How can polyploidy occur? | 1. Formation of a diploid gamete 2. Triploids |
| What is the ultimate consequence of polyploidy in humans? | Spontaneous abortions, stillbirths |
| What is aneuploidy? | Cells missing a single chromosome or having an extra one |
| Identify and distinguish two types of aneuploidy | Trisomy - an extra chromosome; Monosomy - a missing chromosome |
| For what 5 chromosomes are aneuploids more tolerated in humans? | 13, 18, 21, X, Y |
| Give the 4 types of chromosomal mutations involving either extra, missing or rearranged genetic material | 1. Deletions 2. Duplication 3. Inversions 4. Translocations |
| Nondisjunction | During meiosis, the name for the error that results in aneuploidy |
| 47, +21 | Down Syndrome |
| 47, +18 | Edward Syndrome |
| 47, +13 | Patau Syndrome |
| 45, X | Turner Syndrome |
| 47, XXX | Triplo-X (females) |
| 47, XXY | Klinefelter (males) |
| 47, XYY | Jacobs (men) |
