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D.N.A. judger310. D. D. 1:0 1:1 1:3 3:1. DD. DD. D. - PowerPoint PPT Presentation
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D.N.AIn humans, the allele for
dimples (D) is dominant. The allele for not having dimples (d) is recessive. A woman (DD) and a man (Dd) have four children. Which of these if the predicted ratio of the children with dimples to the children without dimples?
D
d
D
D
DD DD
Dd Dd
a.1:0b.1:1c.1:3d.3:1
judger310
D.N.A
XbXb
XBXB
XBXb
XbY
XBY
In fruit flies, eye color is sex-linked. Red is dominant to white. What are the genotypes of these flies:
White eyed, male_____________ White eyed, female_________ Red eyed, male___________ Red eyed, female_________ Red eyed, female (hetero) ____
Cross a heterozygous red eyed female and a white eyed male.
XR Xr
Xr
Y
XRXr XrXr
XRY XrY
What if in the above cross, 100 males and 200 females were produced. How many total red-eyed flies would be produced?
50% of 100 = 5050% of 200 = 100
TOTAL = 150
ON TO 4TH QUARTER!
IN ORDER TO DETERMINE WHETHER A DISEASE OR TRAIT WILL BE PASSED TO FAMILY MEMBERS, A PEDIGREE IS CREATED
PEDIGREE
A PEDIGREE CHART Is a map of a family’s genotypes It can be used to trace a disease or interesting
trait through a family
A square represents a male
A circle represents a female
If it is filled in, means the male or female has a trait
Effected Female Effected Male
Uneffected male
Uneffected female
If it is unfilled in, means the male or does not express the trait or is
homozygous recessive
A horizontal line between a circle and a square means that they are married
If there is a line coming down from the connected couple, it
means they have children
HOW MANY MALES ARE THERE IN THE FAMILY?HOW MANY FEMALES ARE THERE IN THE FAMILY?HOW MANY PEOPLE IN THE WHOSE FAMILY HAVE THE DISEASE?WHAT IS THE SEX OF THE PARENT WHO HAS THE DISEASE?
67
4
Female
IN HUMANS, THE ALLELE FOR HAVING FEET WITH NORMAL ARCHES IS DOMINANT (A). THE ALLELE FOR FLAT FEET IS RECESSIVE (A). THE PEDIGREE BELLOW SHOWS THE OCCURRENCE OF NORMAL ARCHES AND FLAT FEET IN FOUR GENERATIONS OF A FAMILY. IN THE PEDIGREE, INDIVIDUALS ARE IDENTIFIED BY THE GENERATION AND INDIVIDUAL NUMBERS.
