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Genetics. If molecule Y represents a DNA molecule, then molecule W represents what?. Glucose Nucleotide Amino Acid RNA Lipid. Where in the cell does transcription take place?. Cytoplasm Mitochondria Nucleus Golgi Body Vacuole.

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if molecule y represents a dna molecule then molecule w represents what
If molecule Y represents a DNA molecule, then molecule W represents what?
  • Glucose
  • Nucleotide
  • Amino Acid
  • RNA
  • Lipid
where in the cell does transcription take place
Where in the cell does transcription take place?
  • Cytoplasm
  • Mitochondria
  • Nucleus
  • Golgi Body
  • Vacuole
mrna is synthesized in the nucleus and travels to the cytoplasm to meet up with which organelle
mRNA is synthesized in the nucleus and travels to the cytoplasm to meet up with which organelle?
  • Mitochondria
  • Ribosome
  • Golgi Body
  • Lysosome
  • Nucleus
where in the cell does translation the second part of protein synthesis take place
Where in the cell does translation, the second part of protein synthesis, take place?
  • Mitochondria
  • Nucleus
  • Golgi body
  • Cytoplasm
if molecule y represents a protein then molecule w represents what
If molecule Y represents a protein, then molecule W represents what?
  • Glucose
  • Nucleotide
  • Amino Acid
  • RNA
  • Lipid
mutations
Mutations
  • Deletion
    • Occurs when part of a chromosome is left out
    • Most are lethal
mutations9
Mutations
  • Insertion
    • Segment of a chromosome is removed and inserted into another one
mutations10
Mutations
  • Duplication
    • Segment of DNA is copied twice
mutations11
Mutations
  • Inversion
    • Occurs when part of a chromosome breaks off and is reinserted backwards
mutations12
Mutations
  • Translocation
    • Occurs when segments of DNA on 2 chromosomes are rearranged
some vocab first
Some Vocab first
  • Heredity
    • The passing on of characteristics from parents to offspring
  • Trait
    • Characteristic that is inherited
what is a gene
What is a gene?
  • A region of DNA that controls a hereditary characteristic
  • Give me an example:
    • Let’s take the gene for hair color
    • How many different genes are present in this room?
  • Different forms of genes are called
    • Alleles
  • For the gene for hair color how many different alleles do each of you have?
    • 2
where did it all begin
Where did it all begin?
  • With Gregor Mendel
mendel
Mendel
  • Mendel used pea plants to study what genetics really was.
  • He would cross pollinate them to see what kind of products he would get and then make assumptions as to what was happening to the genes.
  • Let’s look at how a plant reproduces
  • http://www.dnaftb.org/dnaftb/1/concept/index.html
mendel19
Mendel
  • What was Mendel seeing?
  • http://www2.edc.org/weblabs/Mendel/mendel.html
let s take a trip down history lane
Let’s take a trip down history lane…
  • Mendel took two pea plants that were identical in every way except for their heights, one was short and one was tall.
  • He called these two plants the parent generation, which is some vocab that we still use today. It’s abbreviated – P1
history trippin
History Trippin
  • He cross pollinated them and took a look at their offspring.
history trippin22
History Trippin
  • When he planted the seeds from the cross pollination the plants that were produced were all tall.
  • He called the offspring from this first cross between the parents – the F1 generation
  • Filial is latin for son or daughter
history trippin23
History Trippin
  • Next, Mendel allowed the tall plants in the F1 generation to self pollinate. He then planted these seeds and grew 1000 plants.
  • Mendel found in this F2 generation that ¾ of the plants grew tall and ¼ were short.
why was this a big discovery for mendel
Why was this a big discovery for Mendel?
  • 1 trait of a pair seemed to disappear in the F1 generation, only to reappear unchanged in ¼ of the F2 plants.
mendel s conclusions
Mendel’s Conclusions
  • Gregor Mendel didn’t know much if anything about DNA or what it was, and he didn’t even know how much you know…so what was Mendel’s big conclusion after seeing his offspring?
  • He figured out that each organism must have 2 factors that control each of its traits.
the rule of dominance
The Rule of Dominance
  • In Mendel’s F1 offspring plants, there were only tall plants even though one of the parents was a short plant.
  • 1 of the alleles is dominant over the other.
the rule of dominance27
The Rule of Dominance
  • The observed trait is DOMINANT and the trait that disappeared is recessive.
  • In Mendel’s example which is the dominant trait and which is the recessive trait?
  • The allele for tallness is DOMINANT
  • The allele for shortness is recessive
how many of you have a widow s peak
How many of you have a widow’s peak?
  • Widow’s peak is dominant
how many of you have attached ear lobes
How many of you have attached ear lobes?
  • Attached earlobes are recessive
how many of you have a straight thumb
How many of you have a straight thumb?
  • Straight thumb is recessive
how many of you have blue eyes
How many of you have blue eyes?
  • Blue eyes are recessive
how many of you have freckles
How many of you have freckles?
  • Having freckles are dominant
how many of you have a cleft chin
How many of you have a cleft chin?
  • Having a cleft chin is recessive
how many of you when clasping your hands together the left thumb is on top of the right thumb
How many of you when clasping your hands together, the left thumb is on top of the right thumb?
  • Left thumb on top is dominant
the rule of dominance42
The Rule of Dominance
  • We label or designate alleles with letters.
    • (For example, a letter T for the trait of height)
  • An uppercase letter is used for the Dominant allele (T for tall)
  • A lowercase letter is used for the recessive allele (t for short)
the rule of dominance43
The Rule of Dominance
  • Using the letter T what can you say about the possible alleles that the following people have on the genes on their chromosomes?
mendel s law of segregation
Mendel’s Law of Segregation

What happens during Meiosis?

Mendel’s law of segregation explains the results of his cross between F1 tall plants. He concluded that the 2 alleles for each trait must separate when sex cells are formed. A parent, therefore, passes on at random only one allele for each trait to each offspring.

let s make another baby
Let’s Make Another Baby!
  • How many chromosomes do we have in our cells?
  • How many came from Mom?
  • How many from Dad?
  • How many alleles for hair color did you receive from your mother?
  • How many alleles for hair color did you receive from your father?
  • If you have 2 alleles for hair color how come half of my head isn’t blonde and half isn’t brown?
genetics vocabulary
Genetics Vocabulary
  • Phenotype
    • The way an organism looks
    • Give me an example
  • Genotype
    • The gene combination an organism has
    • Give me an example
    • *Problem: You can’t always know an organism’s genotype simply by looking at its phenotype
genotype
Genotype
  • Homozygous
    • An organism’s 2 alleles are the same
    • 2 capital letters would be homozygous dominant
      • Give me an example
    • 2 lowercase letters would be homozygous recessive
      • Give me an example
  • Heterozygous
    • An organism’s 2 alleles for a trait are different
    • Give me an example
let s revisit meiosis again
Let’s revisit Meiosis again
  • What happens in Metaphase 1
    • The law of independent assortment
  • Genes for different traits (for example seed shape and seed color) are inherited independently of each other.
  • In our class example we used hair color, number of toes, and eye color
    • We saw depending on how they randomly lined up with each other that you could tons of different combinations.
punnett squares
Punnett Squares
  • In 1905, Reginald Punnett, an English biologist, devised a way of finding the expected proportions of possible genotypes in the offspring of a cross.
  • If you know the genotypes of the parents, you can use a Punnett square to predict the possible genotypes of their offspring.
monohybrid cross
Monohybrid Cross
  • Let’s consider Mendel’s first monohybrid cross between his true-breeding Tall plants and his true-breeding short plants. (P1 -> F1)
  • Each letter (allele) separates into a possible gamete (sex cell).
mendel s second monohybrid cross
Mendel’s Second Monohybrid Cross
  • Now let’s look at Mendel’s second monohybrid cross between his heterozygous F1 generation self-pollinating themselves. (F1 -> F2)
probability
Probability
  • Punnett squares show all of the possible combinations of gametes and the likelihood that each will occur.
    • In reality, however, you don’t get the exact ratio of results shown in the square. That’s because genetics is like flipping a coin, meiosis leaves it up to chance.
  • After completing a punnett square you are able to calculate the probabilities of what offspring will be produced.
  • Let’s calculate some probabilities
sex linked genes
Sex Linked Genes
  • The X and Y chromosomes carry the genetic information that makes us male and female
  • They also contain genetic information for some other traits
  • What combination of sex chromosomes do girls have?
  • What combination of sex chromosomes do boys have?
sex linked genes56
Sex Linked Genes
  • Who determines the gender of the baby?
sex linked genes57
Sex Linked Genes
  • Since men only have 1 X chromosome they will display the characteristics of these traits even if they are caused by a recessive allele
sex linked genes58
Sex Linked Genes
  • There are about 1,098 human X-linked genes.
  • Most of them code for something other than female anatomical traits.
  • Many of the non-sex determining X-linked genes are responsible for abnormal conditions such as hemophilia, red-green color blindness, congenital night blindness, some high blood pressure, duchene muscular dystrophy, fragile-X syndrome, and male pattern baldness.
sex linked inheritance problems
Sex Linked Inheritance Problems
  • In humans, red-green colorblindness is a recessive sex-linked trait. It is found on the X chromosome, not the Y. Because, males only have one X chromosome, they have a much greater chance of having red-green colorblindness. Females would have to be homozygous recessive in order to have red-green colorblindness.
colorblindness62
Colorblindness
  • Normal vision – 8 red green color blind - 3
sex linked inheritance practice
Sex Linked Inheritance Practice
  • A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A woman with normal vision whose father is color-blind marries a color-blind male. What is the probability that a son of this couple will be color-blind?
pedigrees70
Pedigrees
  • A pedigree is a diagram of family relationships that uses symbols to represent people and lines to represent genetic relationships.
  • These diagrams make it easier to visualize relationships within families, particularly large extended families.
  • Pedigrees are often used to determine the mode of inheritance (dominant, recessive, etc.) of genetic diseases.
pedigrees71
Pedigrees
  • Squares represent Males
  • Circles represent Females
  • Horizontal lines connecting a male and female represent mating
  • Vertical lines extending downward from a couple represent their children
  • Oldest individuals are found at the top and youngest on the bottom
pedigrees72
Pedigrees
  • Completely shaded in individuals posses the trait
  • Half shaded in individuals are carriers of the trait
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