Download Genetics - WalkerSci7and8

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Explain how genes are responsible for certain
traits that we acquire from our parents?
In complete sentences, explain meiosis and
explain its role in sexual reproduction.
Remember to include heredity.
http://app.discoveryeducation.com/player/vi
ew/assetGuid/AC056D43-D1C5-4200-AB9BE564C7C74009
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Video Questions:
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Q: What do you know about genetics?
Q: What does the term “Mendelian Trait” describe?
Q: What do you know about genetic mutations?
Q: What are transposons?
Q: What do you know about DNA and describe the
structure of DNA?
Q: How does RNA work?
Q: What do you think will be some future applications
of genetics?
Q: What are the possible future applications for RNA
interference?
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Austrian monk who studied
mathematics and science
As a boy he could predict the
possible types of flowers and fruits
that would result from crossbreeding
two plants in his father’s garden
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Curiosity about the connection
between the color of a pea flower
and the type of seed that same plant
produced inspired him to begin
experimenting with garden peas in
1856.
Made careful use of scientific
methods, which resulted in the first
recorded study of how traits pass
from one generation to the next.
The study of how traits are
inherited through the
interactions of genes.
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The material that controls
which traits are expressed in
an organism
Genes come in pairs and
offspring inherit one copy of
each gene from each parent
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Heredity
Allele
Trait
The passing of traits from
parent to offspring
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The different forms of a trait
that a gene may have
One form of a gene
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Ways of looking, thinking, or
being
Traits that are genetic are
passed down through the
genes from parents to
offspring
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A trait that is covered over,
or dominated, by another
form of that trait and seems
to disappear
Hidden when the other copy
of the gene contains the
dominant allele.
A recessive allele shows up
only when there is no
dominant allele present
Shown with a lower-case
letter
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Both alleles [forms of the gene]
are the same
When offspring inherit two
dominant genes, (one dominant
gene from each parent) they are
said to be homozygous dominant
When offspring inherit two
recessive genes, (one recessive
gene from each parent) they are
said to be homozygous recessive
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When alleles occur in different
forms
When offspring inherit one
dominant gene and one recessive
gene, they are said to be
heterozygous
Since the dominant gene will be
expressed, they are said to be
heterozygous dominant
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When an organism has two
different alleles for a gene that
does not follow the
dominant/recessive pattern
The organism shows a trait that is
a blend of the traits represented
by the two alleles
Also called INCOMPLETE
DOMINANCE
For example:
The gene for the color of some
flowers has one allele for red and
one for white. When both alleles
are present, neither is dominant,
and the flower color is pink
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A trait that covers over, or
dominates, another form of
that trait
Trait that always shows up,
even when only one of the
two alleles is in the
dominant form
Shown by a capital letter
An organism's genetic makeup
Outward physical appearance and
behavior of an organism
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A tool to predict the probability of
certain traits in offspring that
shows the different ways alleles can
combine
A way to show phenotype & genotype
A chart that shows all the possible
combinations of alleles that can
result when genes are crossed
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Letters stand for dominant and
recessive alleles
An uppercase letter stands for a
dominant allele
Lowercase letters stand for recessive
alleles
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Now you need two parents to mate, ones with
a known genotype
For example, a red flower (genotype Rr) and a
white flower (genotype rr). Rr x rr
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Place one of the parents on top, and one on the
left. You should get a something similar to
this:
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The two-letter combinations are the possible
genotypes of offspring
They are: Rr, Rr, rr, and rr genotypes
From this it is possible to determine the
probability (chance) that a flower will have a
red phenotype (2/4 or 50%) or a white
phenotype (2/4 or 50%)
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Traits are controlled by alleles on
chromosomes
An allele’s effect is dominant or
recessive
When a pair of chromosomes
separate during meiosis the
different alleles for a trait move
into separate sex cells
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A trait that is controlled by more
than two alleles is said to be
controlled by multiple alleles
Traits controlled by multiple
alleles produce more than three
phenotypes of that trait
For Example:
The alleles for blood types in humans
are called A, B, and O
The O allele is recessive to both the A
and B alleles
When a person inherits one A allele
and one B allele for blood type,
both alleles are expressed
The person has the blood
phenotype AB
A person with phenotype A blood
inherited an A and an O allele
(AO)
~OR~
an A and an A allele (AA)
Someone with phenotype B
blood has the genotype BB
or BO
This person inherited either a
B and an O allele
~OR~
Two B alleles
A person with phenotype O blood
has the genotype OO
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Occurs when a group of gene pairs
acts together to produce a trait
The effects of many alleles produces
a wide variety of phenotypes
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A student notices that fruit flies with curly
wings trait develops straight wings if kept at
temperature 16 degree Celsius. The best
explanantion for this observation is that
(a) wing shaped is controlled by behavior
 (b) wing shaped is influenced by light intensity
 (c) gene expression can be modified interactions with
environment
 (d) gene mutations for the wing shape can occur at
high temperatures
 EXPLAIN WHY YOU CHOOSE YOUR ANSWER.
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Pick and answer
and explain why
you chose that
answer.