Download Chapter 10- Cell Growth and Division

Genetics
Chromosome Number
Fruit fly example:
8 chromosomes total
__ came from male parent
__ came from female parent
Genetics
Homologous chromosomes- paired
chromosomes having genes for the same
____ located at the same _____ on the
chromosome
______- having two of each kind of
chromosome (__); normal body cells
Diploid cells have two complete sets of
chromosomes/two complete set of genes
Genetics
Gametes (sex cells) of sexually reproducing
organisms have only a _____ set of
chromosomes
_______- having one of each kind of
chromosome (__)
Fruit fly gametes would be n = 4
Genetics
The Work of Gregor Mendel
________- scientific study of heredity
_______ ______- Austrian monk who
experimented using pea plants
Determined rules of inheritance
____________- joining of male & female
gametes to form single cell
Genetics
Genes & Dominance
Studied 7 different pea plant ____
_____- a characteristic that can be passed
on to offspring
For each trait, studied a contrasting
character:
Ex. _____ _____- green or yellow
Genetics
Original pair of plants = __ generation
Offspring = __ generation
_______- offspring of parents that have
different forms of a trait
Results?
Every offspring had a character of ____
____of the parents
Chapter 11- Genetics
Two conclusions:
• Inheritance determined by ______ passed
from one generation to the next
____- the functional units of inheritance
Each trait controlled by ___ gene with ___
contrasting forms
_______- alternate forms of a gene
Genetics
Second conclusion called the principle of
__________:
• Some alleles are _______ and others are
________
________- an allele of a gene that is always
expressed (__)
_________- an allele of a gene that is
expressed only when the dominant allele
is not present (__)
Genetics
Segregation
What had happened to _________ alleles
(traits) in plants?
Mendel allowed __ plants to self-pollinate
Produced __ generation which showed
recessive trait in 1 out of 4 plants (__ ratio)
Genetics
Dominant allele ________ recessive trait in
F1 generation
Reappearance in F2 generation showed that
at some point alleles became ________
Mendel suggested that they _________
from one another during ______ formation
Genetics
Law of Segregation- states that every
individual has ____ alleles of every gene;
when gametes are produced, each gamete
receives ____ of these alleles
Genetics
Probability & Punnett Squares
Every time Mendel repeated a particular
cross, he obtained _________ results
¾ plants showed ________ trait; ¼ showed
________ trait
Mendel realized that __________ could be
used to explain results
Genetics
Genetics & Probability
__________- the likelihood that a particular
event will occur
Two possible outcomes for a coin flip:
heads or tails
Probability of each occurring is _____
Chance of heads is 1 in 2, or ____
Genetics
Chance of heads coming up three in a row?
Each flip is an ______________ event:
Probability of three heads in a row½ x ½ x ½ = ____
Way alleles segregate is _______, like a
coin flip
• Principles of probability can be used to
________ outcomes of genetic crosses
Genetics
Punnett Squares
Gene combinations from a given cross can
be determined using a ________ ______
Letters in Punnett square represent ______
________ from each parent are shown
along one side and the top of the square
Used to _______ and _______ genetic
variations resulting from a cross
Genetics
__________- if an organisms two alleles for
a trait are the same
Can be homozygous dominant (__) or
homozygous recessive (__)
_____________- when the two alleles for
the same trait are different (__)
Homozygous = ________ for trait
Heterozygous = ________ for trait
Genetics
__________- the physical expression of the
genes; how the trait looks
Ex.Tall; short; yellow seeds; green seeds
_________- allele combination that an
organism contains
Ex.TT; Tt; tt
Genetics
Probability & Segregation
Probability predicts that if the alleles
_________, then a ___ phenotypic ratio
should be seen
Each cross showed a 3:1 ratio
Mendel’s law of segregation proven correct
Genetics
Since probabilities predict __________:
the larger the number of __________, the
closer the _____ comes to the probability
Genetics
Exploring Mendelian Genetics
Mendel further investigated:
Alleles segregatebut do alleles _________ together?
or are they __________ of one another?
Genetics
Independent Assortment
Mendel followed two _________ genes
through two generations
Crossed purebred plants for seed _____
and seed ______
Round, yellow seeds (____)
with
Wrinkled, green seeds (____)
Genetics
Only provided hybrid plants needed for next
cross
All F1 plants had genotype ____
F2 generation showed ___ plants that had
phenotypes not found in the ________
So…
Alleles for different traits segregate
___________ of one another
Genetics
Summary of Mendel’s Principles
• Inheritance is determined by individual
units called ______.
Genes passed from _______ to ________.
• When two or more forms (_______) of a
gene exist, some forms may be ________,
others _________.
Genetics
• In most sexually reproducing organisms,
each adult has ___ copies of each gene –
one from each parent.
These copies are _________ from one
another during ______ (gamete formation)
• Alleles for _________ genes usually
segregate ___________ of one another
Genetics
Complex patterns of Inheritance
Important exceptions to Mendel’s principles
Some alleles are _______ dominant nor
recessive
Many traits controlled by ________ alleles,
or multiple genes
Genetics
Incomplete dominance
Appearance of a ______ phenotype
Due to one allele being not completely
_________ over another
3rd phenotype somewhere __ ________ the
two homozygous phenotypes
Genetics
Codominance
Expression of _____
alleles
(ex. White bull
crossed with a red
cow yields a roan
calf)
Both alleles contribute
to the __________
Genetics
Multiple phenotypes from multiple alleles
• More common for multiple alleles to
control a trait in a __________
• Only two alleles of a gene can exist within
the _______
• Multiple ______ for a single _____ can be
found within a population
Examples:
_____ _____- A, B, o
______ _____ ____- C, cch, ch, c
Genetics
Polygenic Inheritance
• Traits that are determined through
expression of ___ ___ _____ genes
• Polygenic traits show wide _____ of
phenotypes
• Ex- _________, __________, _______
Genetics
Genetics & the Environment
Characteristics of any organism not solely
determined by ______
Determined by interaction between genes
and _________
Genes provide ____, how plan goes also
depends on ___________