Lecture--Chapter 8 Flashcards
one that uses a light microscope to study the structure and number of chromosomes
cytogeneticist
Different species can be distinguished from each other based on:
chromosome number, size, and staining
size, position of centromere, banding pattern from stains for:
chromosome classification
position of centromere:
short arm: p; long arm: q
the number and appearance of chromosomes in the nucleus
karyotype
Chromosome classification: banding:
light and dark patterns can be enhanced by stains
G bands
Geimsa stain; best with prometaphase chromosomes
can be changed by mutation
chromosome structure
change in total genetic information:
- deletions
2. duplications
loss of a chromosomal segment
deletions
repetition of a chromosomal segment compared to the normal parent chromosome
duplications
Chromosome structure: genetic material/information rearranged:
- inversions
2. translocations
a change in the direction of part of the genetic material along a single chromosome
inversions
segment of one chromosome becomes attached to a non-homologous chromosome
translocations
generally associated with a strand break
deletions
Phenotypic consequences of deficiencies depends on:
the size and nature of the deletion
Autosomal deletions generally cause:
growth failure, mental retardation, and multiple malformations
associated with errors during recombination
duplications
_____ at misaligned sites with repetitive sequences
unequal crossing over
duplications often have:
no phenotypic effect
relatively few human syndromes are cause by:
small chromosomal duplications; Charcot-Marie-Tooth disease
duplications produce:
additional gene copies
The copied genes may accumulate mutations which alter their function: leading to:
formation of a gene family
two or more genes derived from a common ancestor
homologs
homologous genes within a single species that form a gene family
paralogs
oxygen binding paralogs of myoglobin and hemoglobin
human globin genes
