5.3 Continued: Pedigrees

Question 1

What are pedigrees? (2)

Answer 1

• many human traits follow Mendelian patterns of genetics

- pedigrees are family trees that give a visual of inheritance patterns of particular traits

Question 2

If a trait is ____ then one parent must have the trait. These traits do not ____ generations

Answer 2

Dominant, skip

Note that x-linked do skip generations ex. Grandfather to grandson

Question 3

If a trait is x-linked, are there usually more males or females?

Answer 3

Males

Question 4

What are traits of x-linked RECESSIVE disorders in pedigrees? (5)

Answer 4

• more males than females affected
• an affected son can have parents who have the normal phenotype
• female must have the characteristic. Mother must have it or be a carrier
• characteristic often skips generations from grandfather to grandson
• if a woman has characteristics, so will her sons

Question 5

What are the traits of autosomal recessive disorders in pedigrees? (5)

Answer 5

1. Most affected children have unaffected parents
2. Heterozygotes (Aa) have an unaffected phenotype
3. Two affected parents will always have affected children
4. Close relatives who reproduce are more likely to have affected children
5. Both males and females are affected with equal frequency

Question 6

Please see videos

Answer 6

I didn’t watch them yet

Question 7

What are characteristics of autosomal dominant disorders? (5)

Answer 7

• affected children will usually have an affected parent
• heterozygotes (Aa) are affected
• Two affected parents can produce an unaffected child
• two unaffected parents will not have affected children
• both males and females are affected with equal frequency