Gene Segregation and Interaction (LEC) Flashcards
according to Gregor Mendel (1865) can be analyzed through transmission of visible
characteristics in pea plants.
Genes
Genes according to ___ ___ (1865) can be analyzed through transmission of visible
characteristics in pea plants.
Gregor Mendel
The analysis of genetic crosses depends upon an understanding
of Mendel’s two laws:
principle of segregation
principle of independent assortment
demonstrating that the two members of
a gene pair (alleles) segregate (separate) from each other in the formation of gametes
principle of segregation
indicating that the genes for different traits separate independently
of one another and combine randomly in the formation of gametes during meiosis.
principle of independent assortment
can be defined as the mechanism of how progeny receives genetic information
from the parent.
inheritance
This simply means that due to ___, the members of the same family
possess similar characteristics. I
inheritance
During that period, he chose some distinct characteristics of the peas and conducted some
cross-pollination/ artificial pollination on the pea lines that showed stable trait inheritance
and underwent continuous self-pollination. Such pea lines are called ___ pea line
true breeding
In a monohybrid cross performed by Mendel, he took two pea plants of opposite traits
(one short and one tall) and crossed them. He found the first generation offsprings were tall
and called it __progeny
F1
Then he crossed F1 progeny and obtained both tall and short plants in
the ratio ___ in F2
3:1
Mendel even conducted this experiment with other contrasting traits like green
peas and yellow peas, round vs wrinkled, etc. In all the cases, he found that the results were
similar. From this, he formulated the Laws of __ and __
Segregation and Dominance
states that during the production of gametes, two copies of each
hereditary factor segregate so that offspring acquire one factor from each parent
law of segregation
alternative form of the gene
allele
In other
words, ___(alternative form of the gene) pairs segregate during the formation of gamete.
allele
According to the law of ___, hybrid offsprings will only inherit the dominant trait in the
phenotype
dominance
. The alleles that are suppressed are called as
recessive traits
s while the alleles
that determine the trait are known as the
dormant traits
Another experiment conducted by Mendel is a ___ cross, Mendel considered two traits,
each having two alleles
dihybrid
He crossed wrinkled-green seed and round-yellow seeds and
observed that all the first generation progeny (F1 progeny) were round-yellow. This meant
that dominant traits were the round shape and yellow color. He then self-pollinated the F1
progeny and obtained 4 different traits wrinkled-yellow, round-yellow, wrinkled-green seeds
and round-green in the ratio ____
9:3:3:1
He then self-pollinated the F1
progeny and obtained 4 different traits wrinkled-yellow, round-yellow, wrinkled-green seeds
and round-green in the ratio 9:3:3:1. After conducting for other traits, the results were found
to be similar. From this experiment, Mendel formulated the law of
independent assortment
states that a pair of trait segregates independently of another pair during gamete
formation.
law of independent assortment
As the individual heredity factors assort independently, different traits get ___
opportunity to occur together.
equal
Mendel extended his observations to ___crosses involving three pairs of contrasting
characters.
trihybrid
character where mendel did a monohybrid cross
stem length (short and tall)