Non-Mendelian Genetics. Inheritance patterns that don’t follow the rules. A. Linkage. 1. Image of Bateson and Punnett 2. tried to replicate work of Mendel using other traits of garden pea 3. traits investigated -flower color P (purple) and p (red flowers)
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Inheritance patterns that don’t follow the rules
body color and another dominant gene for normal wings.
color and vestigial wings respectively.
Flies homozygous for gray body and normal wings were crossed with flies that had black bodies and vestigial wings.
The F1 progeny were then test-crossed, with the following results:
B andC 20%
C and D 10%
C and A 20%
D and B 10%
produces many offspring, all colored.
a. so far been discussing traits that are governed only by one gene
b. far from the truth
c. most phenotypes that we are aware of are distributed in a bell-shaped curve like human height
d. often multiple genes affect such traits
e. height in plants might be affected by three genes each possessing two alleles
f. the dominant allele of each gene might add 1 cm to basic height of plant
g. the recessive allele of each gene would not affect the basic 10 cm height
h. aabbcc X AABBCC
i. F1 generation selfs itself
j. 1/64 6/64 15/64 20/64 15/64 6/64 1/64
k. the more genes affecting a trait, the smoother is the bell curve
l. the environment also affects phenotype smoothing off the curve even more
1. human condition there are 23 pairs of homologous chromosomes
-a. appear as a female phenotypically
-b. the female pattern is the default pattern set to develop as female unless something triggers a change-
-c. but doesn’t develop into the adult pattern
-d. hips and breasts remain immature
-e. no Barr bodies
-f. mental function is not impaired
-g. 1/5000 affected
-h. approximately 15-20% of aborted fetuses