lab 5 Flashcards
a gene can come in different forms called?
alleles
what is a dominant allele
one whose phenotypic effect is the same in both heterozygous and homozygous conditions
what is a recessive allele
is one that is not expressed phenotypically in heterozygous forms
what are heterozygous
has two different alleles for the gene
what type of organism is a heterozygous
diploid organism
what are homozygous
has two identical alleles for the gene
what type of organism is a homozygous
diploid organism
what are genotypes
genetic makeup of an organism,
how are genotypes expressed
with letters AAaa
what are phenotypes
physical appearance of an organism for a particular trait
how are phenotypes expressed
with descriptive words (tall seeding)
what is frequency
the proportion of one type of thing to total population
what is used to separate items in a series for frequency
comas
what is used to separate items in the ratio
colons
what is a ratio
proportion of one type of thing to another
how do you calculate ratio
divide all numbers in a series by the lowest number
what are two original parents represented by
P1 and P2
what are the offspring of P1 and P2 represented by
F1
how are the offspring from F1 a result of
self-fertilization
what is F2 generation called
second filial
what is a gene
a factor of inheritance for a particular trait/ characteristic of an organism
what is a gene composed of
specific nucleotide sequence in DNA
what does nucleotide sequence acts as
template for RNA synthesis and formation of specific protein in cell
what is a punnett square
used to simulate all possible combinations of male and female gametes to form offspring
what is a monohybrid cross
between two organisms that differ in respects to one characteristic (Aa)
what is mendels first law
alleles of one gene segregate from one another during formation of gametes
what is the principle of dominance
when parents differ in one characteristic, their hybrid offspring resemble only one parent and not a blend of both
what is the principle of segregation
half passing on dominant character of one parent and other half passing on recessive character
what is a dihybrid cross
is between two organisms that differ with respect to two characteristics
how many genes should a diploid have
should have two copies of each gene AABB
hoe many genes should a haploid have
only one of each gene AB
what is mendels second law
alleles of different genes assort independently of one another during gamete formation
will there be an equal chance or unequal chance of genes being assorted independently
equal chance that an allele of one gene ends up with either of the alleles of other gene
what is a test cross
crossing an individual of unknown genotype with homozygous recessive individuals
different chromosomes are _________________
independent assortment
same chromosomes are _________
gene linkage
if two +genes are located _________ ________on a chromosomes, they move __________ during formation
close together and together
when genes are close together and move together during gamete formation what are they
linked
what is crossing over
genetic exchange that occurs between homologous chromosomes in prophase 1
what happens is two genes are far apart
expect a greater chance of a breakage occuring somewhere between two genes in question
what is the result of two genes that are far apart
relatively large number of recombinant gametes (closer to 0.5)
what is the result of two genes that are two close together
recombinant offspring would be closer to frequency 0
what happens if two genes are close together
expect fewer breakages to occur between and result in low number of recombinants
characteristics that are passed from parents to offspring are actually ______ located on __________
genes and chromosomes
