click below
click below
Normal Size Small Size show me how
BIO Chapter 15
Chromosomal Basis of Inheritance
| Term | Definition |
|---|---|
| Who is Thomas Hunt Morgan? | geneticist that experimented with the color of fruit fly eyes |
| Why did Morgan study fruit flies? | easy to control, produce a lot of offspring |
| What major discover about genetics did Morgan make? | sex-linked genetic traits |
| How many pairs of autosomes in a human? | 22 |
| How many sex chromosomes? | 1 pair |
| Sex linked recessive disorders- | disorders what are linked to the X chromosome and occur in men much more frequently than in women |
| Mary Lyon’s dosage compensation hypothesis- | Barr bodies |
| Barr bodies- | an inactivated chromosome to deal with an “extra” one |
| Nondisjunction- | results in alterations in chromosome number, when chromosomes fail to split correctly in mitosis or meiosis |
| Aneuploidy- | a change in chromosome number that effects on or several chromosomes in a cell |
| Polyploidy- | change in chromosome number that effects a whole set of chromosomes |
| Trisomy- | extra chromosome in women that results in a major increase in miscarriage likelihood |
| Monosomy- | missing a chromosome |
| Trisomy 21- | down syndrome |
| Trisomy 18- | Edwards syndrome |
| Trisomy 13- | Patau syndrome |
| 47 XXX- | healthy female with two barr bodies |
| 45 X- | infertile female, turner syndrome |
| 47 XYY- | taller than average male, healthy, no conception issues |
| 47 XXY0 | Klinefelter syndrome in males, conception issues |
| 4 types of alterations in chromosome structure- | deletions, duplications, translocation, inversion |
| Deletion- | removes a chromosomal segment, sever symptoms |
| Duplications- | repeat a segment of a chromosome, symptoms can include speech and language delays, social anxiety, diagnosis of autism spectrum disorder, seizures |
| Inversion- | reverses a segment within a chromosome, no huge effects normally |
| Translocation- | moves a segment from one chromosomes to a non-homologous chromosome |
| Genomic imprinting- | gene expression occurs from only one allele |
| Mechanism of genomic imprinting- | epigenetic process that can involve DNA methylation to turn off the expression of an allele |