Read through the review article on Mendel\'s traits paying attention to the introductory section
and highlighted sections later on. List the proposed function of the gene found for the following
characteristics: Seed shape Stem Length Cotyledon (seed) color Flower color An additional
presentation on this work will be done on Thursday February 2 from 7:20-8:15 pm in SCI 109.
Solution
The proposed \"function of the gene\" found for the following Mendel\'s traits such as seed
shape, stem length, cotyledon and flower color:
See shape: the gene functions for the expression of seed shape either round or wrinkled as per
dominant genotype locus expression for seed coat in the phenotypes.
Stem length: Mendel has used this gene i.e. LE gene to control gibberellin levels finally to
determine plant growth and their level of inhibitors based on this gene expression
Mendel’s genes for cotyledon color: this trait was determined by the functions of gene
expression in the offspring by controlling plant senescence & chlorophyll degradation
significantly. It has represented by symbol \"I\"
Flower color: white flowers ---> gene a2; purple dominant flower color trait ---> gene A & these
are expressed for the generation of flavonoid biosythesis, chalcone synthase to produce flower
color as per their expression in the offspring
Speculations:
Mendel used pure-breeding lines of peas for his experiments because these pure breeding pea
plants can produce offspring with “same traits” as parent plant. These progeny pea plants can
cross-bred to generate progeny with recorded genetic phenotypic traits over several generations.
Mendel’s results allowed him to reject the hypothesis of blending inheritance because pure- bred
lines of pea plants allowed him to differentiate “dominant trait” & “recessive trait” over
subsequent generations according to law of segregation. He has concluded that “traits were not
blended” however these traits were remained distinct in subsequent generations, it is contrary
speculation at that time. He could not define the genes as unit factors for these traits.
A classic debate in early genetics and evolution is how to create a model that accounts for the
discrete traits (pea texture, flower color) observed by Mendel. Mendel has examined the
regularity and reproducibility of the trait and the specific transmission from parents to
subsequent generation finally reappeared. For example, he observed that white flower color
reappearance in the 3rd generation after two crosses and finally deduced that there are physical
particles that were transmitted from generation to generation representing a trait, as an
evolutionary aspect. He could not observe these unit factors or unit particles as \"genes\" & their
functions as he did not know initially anything about chromosomes. This gene has different
forms often referred as alleles representing phenotypic features of the offspring. Mendel did not
observe \"unit factors\" (genes) directly, he was able to assoc.
Read through the review article on Mendels traits paying attention .pdf
1. Read through the review article on Mendel's traits paying attention to the introductory section
and highlighted sections later on. List the proposed function of the gene found for the following
characteristics: Seed shape Stem Length Cotyledon (seed) color Flower color An additional
presentation on this work will be done on Thursday February 2 from 7:20-8:15 pm in SCI 109.
Solution
The proposed "function of the gene" found for the following Mendel's traits such as seed
shape, stem length, cotyledon and flower color:
See shape: the gene functions for the expression of seed shape either round or wrinkled as per
dominant genotype locus expression for seed coat in the phenotypes.
Stem length: Mendel has used this gene i.e. LE gene to control gibberellin levels finally to
determine plant growth and their level of inhibitors based on this gene expression
Mendel’s genes for cotyledon color: this trait was determined by the functions of gene
expression in the offspring by controlling plant senescence & chlorophyll degradation
significantly. It has represented by symbol "I"
Flower color: white flowers ---> gene a2; purple dominant flower color trait ---> gene A & these
are expressed for the generation of flavonoid biosythesis, chalcone synthase to produce flower
color as per their expression in the offspring
Speculations:
Mendel used pure-breeding lines of peas for his experiments because these pure breeding pea
plants can produce offspring with “same traits” as parent plant. These progeny pea plants can
cross-bred to generate progeny with recorded genetic phenotypic traits over several generations.
Mendel’s results allowed him to reject the hypothesis of blending inheritance because pure- bred
lines of pea plants allowed him to differentiate “dominant trait” & “recessive trait” over
subsequent generations according to law of segregation. He has concluded that “traits were not
blended” however these traits were remained distinct in subsequent generations, it is contrary
speculation at that time. He could not define the genes as unit factors for these traits.
A classic debate in early genetics and evolution is how to create a model that accounts for the
discrete traits (pea texture, flower color) observed by Mendel. Mendel has examined the
regularity and reproducibility of the trait and the specific transmission from parents to
subsequent generation finally reappeared. For example, he observed that white flower color
reappearance in the 3rd generation after two crosses and finally deduced that there are physical
particles that were transmitted from generation to generation representing a trait, as an
evolutionary aspect. He could not observe these unit factors or unit particles as "genes" & their
2. functions as he did not know initially anything about chromosomes. This gene has different
forms often referred as alleles representing phenotypic features of the offspring. Mendel did not
observe "unit factors" (genes) directly, he was able to associate the behavior of chromosomes
during meiosis to his principles of segregation and independent assortment. Therefore, Mendel’s
experiments a challenge for evolutionary models, as he could not observe these unit factors.
Later, this conflict of examining the evolutionary inheritance of phenotypic traits as some times
some of gene phenotypic features are dominant due to recessive nature of other gene caused by
dominant gene therefore predictable ratios in crosses supported the hypothesis of two hereditary
elements involved in the expression of a given trait.