Chapter 14 ppt ( Mendel and the Gene Idea)
The idea that ___ material contributed by 2 ___ mixes in a manner ____ to the way blue and yellow paints blend to make green
genetic, parents, analogous
An alternative to the blending model is the "______" hypothesis of inheritance also known as the ____
particulate, gene idea
An alternative to the blending model is the "particulate" hypothesis of inheritance ( the gene idea) where parents pass on ___ heritable units (genes)
discrete
Gregor Mendel is known as the father of
genetics
Gregor Mendel documented a particulate mechanism of inheritance through his experiments with ____
pea plants
Mendel chose to work with peas because of what 3 reasons
variety
strictly control mating
short generation ( producing a lot of offspring)
Pea plants have pollen -producing organs (male) known as
stamen
Pea plants have an egg -bearing organ ( female) known as
carpal
character is a ___ feature
heritable
characters are ___
inheritable
is flower color a character or a trait
character
trait is a variation of ___
character
is the purple or white flowers a character or trait
trait
cross fertilization or cross pollination is ______ between _____ plants
fertilization, different
Mendel chose to track only those characters that varied in " __-___" manner with an ___-
either-or, intermediate
purple or white nothing else (seed weight, height .. etc) is an example of what manner
either-or
Menden also made sure that he started his experiments with varieties that were "____-____"
true-breeding
When plants self-pollinate they produce offspring of the __ variety generation after generation
same
Purple plants gave rise to just purple plants or white plants gave rise to just white plants is what manner?
"true-breeding"
In typical breeding experiment mendel mated 2 ___ , ___ varieties
contrasting, true-breeding
In a typical breeding experiment mendel mated 2 contrasting true-breeding varieties in a process known as
hybridization
The true-breeding parents are called the ___ generation
P
The hybrid offspring of the P generation are called the ___ generation
F1
When F1 individuals self-pollinate they produce the ___ generation
F2
( the law of segregation) when mendel crossed contrasting true-breeding white and purple flowered pea plants all of the offspring were
purple
( the law of segregation) when mendel crossed the F1 plants many of the F2 plants had ___ flowers but some had ___ flowers
purple, white
Mendel discovered a ratio of about __-___ purple to white flowers in the F2 generation
3-1
Mendel reasoned that in the F1 plants only the ___ flower factor was affecting the flower color in these hybrids
purple
Purple flower was
dominant
White flower was
recessive
the factor for ___ flowers was not diluted or destroyed because it reappeared in the F2 generation
white
1 trait will be ___ and the other trait will be ___
dominant, recessive
Dominant traits are expressed with
Capital letters
Recessive traits are expressed with
lowercase letters
The dominant trait is expressed ____ % in F1 generation
100
Dominant in F2 generation is always _-_ ratio
3-1
How many concepts make up mendels model
4
( 1st mendels model) alternative versions of genes account for variations in inherited characters known as
alleles
( 1st mendels model) slighly ___ nucleotide sequence on ___ of ____
different, locus, DNA
1 gene equals how many alleles
2
(2 mendel model) an organism inherits __ alleles __ from each parent
2, 1
What are the 4 concepts of mendels model
alleles
each character
if 2 alleles at locus differ
law of segregation
(2 mendel model) either 2 of the ___ allele ( true-breeding) or 2 ___ alleles
same, different
(3 mendel model) if 2 alleles at a locus differ then 1 the ___ allele determines the organisms appearance ( uppercase letter)
dominant
(3 mendel model) if the 2 alleles at a locus differ the other allele the __ allele has no noticeable effect on the organisms appearance ( lowercase letter)
recessive
(4 mendel model) the 2 alleles for a heritable character ___ during ____ formation and end up in ___ gametes
separate ( segregate), gamete, different
gamete formation is known as
gametogenesis
The law of segregation is expressed in what stage of meiosis
anaphase 1
When using a punnett square the dominant trait has to ALWAYS be ___ in the box
first
an organism with 2 identical alleles for a gene is a
homozygote
it is said to be _____ for the gene controlling that character (Ho)
homozygous
homozygous for the gene exhibits ____
true-breeding
PP is what genotype
homozygous dominant
pp is what genotype
homozygous recessive
an organism with 2 different alleles for a gene is a ___
heterozygote
It is said to be ___ for the gene controlling that character (He)
heterozygous
Pp is what genotype
heterozygous
genotype =
alletic combination
heterozygous are NOT _____
true-breeding
an organisms phenotype is its
physical appearance
an organisms genotype is its
genetic makeup
What is the formula for the genotypic ratio:
HD: HE:HR
What is the formula for the phenotypic ratio:
D:R
With any ratio for phenotype or genotype you NEVER
reduce
an individual with the dominant phenotype could be either _____ or _____
homozygous dominant or heterozygous
a test cross allows for us to determine the genotype of an organism with a _____ phenotype but unknown genotype
dominant
A testcross crosses an individual with the dominant phenotype with an individual that is _________ for a trait
homozygous recessive
If any offspring display the recessive phenotype the mystery parent must be ______
heterozygous
Mendel derived the law of segregation by following a ___
single gene
The f1 offspring produced in this cross is called a
monohybrid cross
It is a monohybrid cross as long as the genes are on separate _____ chromosomes
homozygous
Mendel identified his second law of inheritance by following ___ genes at the ___ time
2, same
crossing 2 true-breeding parents differing in 2 characters produce ___ in the F1 generation
dihybrids
in monohybrids heterozygous for __ character(s)
1
in dihybrids heterozygous for __ character(s)
both
a dihybrid cross produces ___ phenotypes in the F2 generation
4
Using the information from a dihybrid cross mendel developed the law of _____
independent assortment
each pair of alleles segregates independently of any other pair during ____ formation
gamete
The law of independent assortment occurs in what stage of meiosis
metaphase 1
Following normal mendel genetics with genes on separate homologous chromosomes in both parents are heterozygous for both genes you will always get a ratio of __:__:__:__
9:3:3:1
Non-mendelian genetics do not follow
normal mendel genetics
the relationship between genotype and phenotype is rarely ___
simple
The inheritance of characters by a single gene may deviate from simple mendelian patterns when (3)
alleles aren't completely dominant or recessive
when a gene has more than 2 alleles
when a single gene produces multiple phenotypes
Spectrum of dominance is when alleles show different degrees of ___ and ___ in relation to each other
dominance , recessiveness
Complete dominance =
mendelian genetics
complete dominance occurs when the phenotypes of the ____ and the dominant ___ are ____
heterozygote, homozygote, identical
PP and Pp both produce purple plants because of
complete dominance
What is an example of complete dominance
cystic fibrosis
Incomplete dominance=
non-mendelian genetics
In incomplete dominance the phenotype of F1 hybrids is somewhere between the phenotypes of the 2 _____
parental varieties
In incomplete dominance there is not enough _____ to block ___
dominant, recessive
What is an example of incomplete dominance
flowers
In codominance 2 dominant alleles affect the ____ in ____, ____ ways
phenotype, separate, distinguished
In codominance there is no ____ allele
recessive
In codominance both are ____ expressed
equally
What is an example of codominance
RBC
a dominant alle do not subdue a recessive alle: the alleles don't
interact
alleles are simply variations in a gene's ____ sequence
nucleotide
For any character, dominant/ recessiveness relationships of alleles depend on the level at which we examine the ___
phenotype
dactyl=
digits
Dominant alleles are not necessarily ____ common in populations than recessive alleles
more
What is an example of the frequency of dominant alleles
polydactyl
polydactyl is when people are born with six ___ or ___
fingers or toes
polydactyl is most common in
cats
most genes exist in populations in more than ____ alletic forms
2
The ABO blood group in humans is determined by ___ alleles by a ____ gene
multiple, single
I A is the presence of
carbohydrate A
IB is the presence of
carbohydrate b
i is not having
any carbohydrate
using multiple alleles example
human blood type
multiple alleles code for
glycoproteins
pleiotropy is a single gene that effects multiple ____ traits
phenotypic
What is an example of pleiotropy
human disease PKU
The human disease PKU causes mental_____ and reduced __ and ___ pigmentation
retardation, hair, skin
The cause of the human disease PKU is a mutation in a single gene that codes for an ___ that converts 1 _____ into another.
enzyme, amino acid
The human disease PKU effects __ parts of the body
many
some traits may be determined by __ or ___ genes
2, more
In epistasis a gene at one locus ___ the ___ expression of a gene at a second locus
alters, phenotypic
many human characters vary in the population among a range and are called ______ characters
quantitative
quantitative characters indicate
polygenic inheritance
polygenic inheritance is 2 or more genes that ___ the ___ of 1 trait
control, phenotype
What is an example of a polygenic inheritance
skin pigmentation, eye-color, height, hair, color, etc.
another departure from simple mendelian genetics arises when the phenotype for a character depends on ____ as well as genotype
enviroment
what is an example for another departure from simple mendelian genetics arises when the phenotype for a character depends on enviroment as well as genotype
amount of water, nutrition, sunlight, etc. all effect growth, hormones, color, protein function and production, etc.
traits that depend on multiple ___ combined with ____ influences are called ____
genes, environmental, multifactoral
an organisms phenotype includes its physical appearance, ______, ___, and ___
internal anatomy, physiology, behavior
an organisms genotype reflects its overall genotype and unique _____
enviromental history
a pedigree is a family tree that describes the ______ of parents and children across generations
interrelationships
a pedigree can't manipulate __ patterns so must use another source
mating
pedigree charts help predict
future
pedigree charts are useful in case of
genetic disorders
many genetic disorders are inherited in a ____ manner
recessive
examples of recessively inherited disorders
albinism, hemophilia, color blindness, cystic fibrosis, sickle-cell anemia
the allele that codes for genetic disorder has either a ___ protein or no ___ at all
malfunctioning, protein
Recessively inherited disorders show up only in individuals _____ for the allele
homozygous
Carriers are ___ individuals who carry the ___ allele but are ___ normal
heterozygous, recessive, phenotypically
Carriers have enough normal __ to function properly
protein
cystic fibrosis common among ___ descent (__% are carriers)
european , 4
(cystic fibrosis) normal allele for gene codes for ___ transport between ___ and ___
Cl-, cells, ECF
(cystic fibrosis) __ transports channels ____ or ____ in cystic fibrosis individuals
Cl-, defective, absent
symptoms of cystic fibrosis
mucus buildup in some internal organs due to high ____ of __
extracellular concentration, Cl-
symptoms of cystic fibrosis
poor ___ of nutrients in the small intestine
absorption
symptoms of cystic fibrosis
chronic ___
bronchitis
symptoms of cystic fibrosis
recurrent ___ infections
bacterial
if cystic fibrosis is untreated , most likely will die by __ years old
5
if treated can survive until ___ to ___ years old
20, 30
sickle-cell disease (ex. pleiotrophy)
affects __ out of ___ african-americans and __ out of __ africans
1, 400, 1, 10
sickle-cell disease (ex. pleiotrophy)associated with low ___ of ___
occurence, malaria
sickle-cell disease (ex. pleiotrophy) is caused by the __ of a single amino acid in the _____ protein in red blood cells
substitution, hemoglobin
Symptoms of sickle-cell disease include
physical weakness, pain, organ damage
symptoms of sickle-cell disease even go as far as ___ due to ___ clogging small____ when __ content is low
paralysis, sickled RBC, BV, O2
little O2= sickle- cell hemoglobin aggregate into long __ that form the red cells into a ___ shape
rods, sickle
in sickle-cell disease the ___ benefit
heterozygotes
mating between relatives can __ the probability of passing on ___ traits
increase, recessive
mating between relatives are called _____, "__" matings
consanguineous, same blood
when mating between relatives more likely mating produces offspring ___ for ___ traits since both relatives are likely to carry the trait
homozygous, recessive
When mating between relatives still __ and ___ are likely
births, birth defects
some human disorders are due to dominant allleles one example is
achondroplasia
achondroplasia is a form of ____ that is ____ when _____ for the dominant allele
dwarfism, lethal, homozygous
achondroplasia affects _ in _ people
1, (25,000)
With achondroplasia ____ % of population is homozygous recessive for this trait
99.99%
in dominantly inherited disorders the ___ allele is more prevalent than the ____ one
recessive, dominant
huntington's disease
__ to___ people
1 to 10,000
huntington's disease
is a ____ disease of the ____ system from a ____ dominant allele
degenerative, nervous, lethal
huntington's disease
has no obvious _____ effects until about ___ to ___ years of age
phenotypic, 35 to 40