Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download SexLinked Genes And Disorders
Document related concepts
no text concepts found
Transcript
SexLinked Genes And Disorders Introduction Human somatic cells, including zygotes, have _________ pairs of chromosomes (total). The first 22 pairs of these are called _______________. The last pair are called ___________ chromosomes. Human females (symbol = _______) are written as: ____________. Human males (symbol = _______) are written as: __________. Gametes produced by females carry only the ______ sex chromosome. Gametes produced by males carry either the _______ or _______ sex chromosome. Question 1 : ● Which gamete determines the sex of the baby? Why? Question 2 : ● Use correct genetic problemsolving (cross, Punnett square, explanation) to determine the probability that a couple will have a female child. SexLinked Disorders The sex chromosomes contain genes that carry genetic disorders such as _________________ (blood fails to clot properly), colour blindness, high blood pressure, muscular dystrophy, etc. Because a female has __ X chromosomes, she has 2 sexlinked genes (one on each X chromosome). But a male can only have 1 sexlinked gene because the __chromosome does not carry a copy of the genes located on the X chromosome. Therefore, males often suffer from more sexlinked disorders. Also, sexlinked disorders are usually caused by _______________ (not dominant) genes. Example: Hemophilia (recessive sexlinked disorder) Normal female = _____________ Carrier female = ______________ Normal male = ______________ Male with hemophilia = _____________ Because the male only has sexlinked genes on the ________ chromosome, there is nothing on the ______ chromosome to mask the _________on the X chromosome. So if a male has even 1 copy of the disordered gene, he suffers from the disorder. A ______ can carry 1 disordered gene on one X chromosome but still have a normal gene to mask it on the other X ____________. A "______ female" usually doesn't suffer from the disorder, she just carries it and can pass it on .... usually to her SONS as you'll soon see! Question 3 : ● Cross a carrier female (for hemophilia) with a normal male. Of all their offspring, H what is the probability they will produce a hemophiliac son? (X = normal blood, h X = hemophilia) Question 4 : ● Cross a hemophiliac female with a normal male. Of all their offspring, what is the H h probability they will produce a hemophiliac daughter? (X = normal blood, X = hemophilia) Question 5 : ● Cross a carrier female (for colour blindness) with a normal male. Of all their B offspring, what is the probability they will produce a carrier daughter? (X = b normal vision, X = colour blind) Q3 Q4 Q5
Related documents