1. What are the genetic symbols, and their meanings?
Mendel used upper and lower cases.T tall, t short. + means that its wild. (mutant phenotype)
dominant-recessive, dominant is upper case, recessive is lower case. F1 is the first generation, F2 is the second generation from F1 generation.
2. Mutations;
.deletion
.duplication
.inversion
.translocation
3. Human disorders, their results.. (caused by chromosome alterations)
down syndrome: an aneuploid condition that's the result of having an extra chromosome 21. Characteristic facial features, short stature, heart defects, mental retardation.
klinefelter syndrome: an aneuploid condition in which a male possesses he sex chromosomes XXY. males have male sex organs but are sterile.
turner syndrome: a monosomic condition in which the female has just one sex chromosome, an X. sterile female organ.
Video on Chromosome Mutations:
A good website about human disorders due to chromosome alterations:
Patterns of Inheritance with Sex-Linked Traits
5 main facts on this chapter:
. In humans, there are two types of sex chromosomes. X is for females, Y is for males. Males have one X and one Y.
. Sex linked genes are usually located in X chromosome. So if a boy is hemophilia, that means that his mom has a recessive/dominant hemophilia gene.
. While genes that are on the same chromosome tend to be inherited together, the process of crossing over enables "linked" genes to sort independently. Those that are linked but located farther apart on the chromosome will undergo crossing over more frequently than those located very close together on a chromosome simply because there are more sites between the two genes at which crossing over can take place.
. Turner syndrome is the only known viable monosomy in humans.
. Fertilization restores the diploid number in a sexually reproducing organism. The two major events in the life cycle of sexually reproducing organism are meiosis and fertilization.
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