Genetics Lecture 7 Flashcards
Describe three characteristics of an ideal organism for genetic study.
Short lifecycle
Easy to grow
Large # of offspring
Are humans convenient for genetic research? Why (3)?
No, due to high generation span, few offspring, and unethical to plan breeding.
What is used for human genetic research? Name 3 difficulties with such a method.
Pedigrees used.
- Records are incomplete
- Cant get reliable information about the deceased
- Reluctance to discuss information
When using pedigrees, what 3 events are hard to account for?
Abortions
Artificial insemination
Illegitimate births
How can pedigrees sometimes be misleading?
Variable expressivity.
Which populations are good for human genetic research and why?
Amish, Mormons, Hutterites
Confined populations, good records, marry amongst themselves.
Are males and females affected in equal numbers by autosomal dominant traits? Can both men and women transmit them?
Yes to both
How many affected parents does an individual with an autosomal dominant trait have?
All affected individuals have at least one affected parent.
Can an autosomal dominant trait be present to the children of two unaffected parents?
No.
How does the trait differ between homozygous and heterozygous individuals to an autosomal dominant trait?
Trait may be more severe in homozygous individuals, sometimes lethal.
Achondroplasia - dwarfism
Are males and females affected in equal numbers by autosomal recessive traits? Can both men and women transmit them?
Yes to both
How many affected parents does an individual with an autosomal recessive trait have?
Most affected individuals will have two unaffected parents. Parents may be affected however.
Which autosomal trait skips a generation? Which appears in every generation?
Recessive skips
Dominant is in every generation
