genetics unit target: model ways in which characteristics of one generation relate to the next...
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GeneticsUnit Target: Model ways in which characteristics of one generation
relate to the next generation.
Learning Target: Explain the experiments of Gregor Mendel and his contributions to the
study of inheritance. (K).
Who is considered the father of genetics?
Gregor Mendel
Heredity characteristic
Gene an allele that masks another allele
Trait the different forms of genes
Allele an allele that is masked
Dominant the passing down of traits
Recessive segments of the DNA that carry the information to create proteins and cells
Which of the following are conclusions made by Mendel?
a. Genes are passed from one generation to the next.
b. Some alleles are dominant and others are recessive.
c. During gamete formation, alleles segregate from each other so that each gamete only carries a single copy of each gene.
d. Genes for different traits can segregate independently during the formation of gametes.
All are conclusion reached by Mendel
4. P stands for parental generation.
5. F1 stands for first filial
1 2
3
The previous slide is an example of:
1.The principle of independent assortment.
2.The principle of segregation.
The principle of segregation- the alleles for each gene segregated from each other so each gamete only had one allele for that particular gene
How does this picture demonstrate independent assortment?
The “R” alleles and “Y” alleles segregate independently from each other. They are not “attached” or dependent on each other.
Learning Target: Gather and analyze data on class traits. (S)
Tre has brown eyes and Ann Marie has blue eyes. What is the genetic trait being discussed?
Eye color
Is ear lobe attachment a continuous or discontinuous trait?
Discontinuous- you are either one thing (attached) or the other (unattached)
Give an example of a continuous trait.
Height, skin color
This girl has got some awesome genes!!!
Julia’s Dad Julia’s Mom Julia
Freckles yes yes yes
Cheek dimples
yes no yes
Free ear lobes
yes no no
1. Which statement is true about Julia and her parents?A. They all have at least one dominant allele for freckles.B. They all have at least one dominant allele for cheek dimples.C. They all have at least one dominant allele for free ear lobes.
A.
Truth or Baloney?
A trait that can be changed by human intervention is tongue rolling.
Baloney. A trait that can be changed by human intervention is hair color.
Can the environment affect genetic traits?
Yes- You may be tall enough to play basketball but unless you are taught how to the play the game you may not develop the athletic ability to play the game.
Learning Target: Complete a dissection of a flower to gather information on how sex cells contribute to the inheritance of genetic traits. (R)
Which # represents the male sex organ?
9 stamen
Which letter represent the female sex organ?
8 pistil
At what # would you find the male gamete?
3 the pollen is found on the anther
If the male gamete fuses with the female sex cell (7- ovule) what will have occurred?
Fertilization
Mouse sperm attempting to fertilize a mouse egg cell.
Learning Target: Differentiate between asexual and sexual reproduction. (R)
Sexual or Asexual?
Results in genetically identical offspring.AsexualResults in genetic variation.SexualFertilization is an example.SexualRegeneration of a body part is an example.Asexual
Learning Target: Interpret a table to differentiate between haploid and diploid cells. (S)
Organism Haploid # Diploid #
Onion 8 16
Earthworm 16 32
Human 23 46
What type of cells are haploid?
Gametes (sex cells)
Why are gametes haploid?
When fertilization occurs each gamete contributes their chromosomes to make a diploid organism.
Learning Target: Compare and contrast mitosis and meiosis. (S)
The number of cells produced by meiosis is two.
False: four
The cells produced during meiosis are genetically identical.
False: different
The cells produced during meiosis are called gametes.
True
The male gamete is dominant over the female gamete.
False: genetically equal to
Why is genetic variation important?
a. It allows for a biological diversity.
b. It allows for adaptation to take place over time as species respond to changing environmental conditions.
c. Both are correct
c.
What is taking place in the picture?
Crossing-over
What do each of the letters represent?
Alleles
Truth or Baloney?
Mitosis produces 2 cells that are genetically different.
Baloney- Alike
Mitosis is important in growth and repair of organisms.
True
Which picture shows meiosis?
The one on the left- it results in 4 gametes with ½ the number of chromosomes.
Use the rules of probability to solve genetics problems with Punnett squares. (R)
Truth or Baloney:
Probability is defined as the likelihood that an event will occur.
Truth
Who invented Punnett squares?
When flipping coins to model genetics, why did you use two coins?
To represent each parents contribution to passing down a trait.
What did heads and tails represent?
The two different forms of the gene (alleles).
Green leave are dominant to yellow striped leaves.
1. Is the parent generation homozygous or heterozygous?heterozygous
2. What is the phenotype ratio of green to yellow striped leaves in the offspring?3 green : 1 yellow striped
How is it possible for two plants with green pods to produce seeds for a plant that will have yellow pods?
The green plants each pass down a recessive allele.
Incomplete dominanceWhat is the genotype of the pink
flowers?
Rr
What is the genotype of the Red flower?
RR
What is the genotype of the white flower?
rr
Why is this incomplete dominance?
Because blending has taken place.
What type of genetic cross is represented by the lizard skin.
Codominance- Many colors are expressed. One color is not dominant over another.
What type of genetic cross is represented in the picture?
Another example of codominance. Isn’t nature cool?
Learning Target: Determine how the sex of an offspring is calculated. (R)
What is the genotype of a male?XY
What is the genotype of a female?
XX
What percent of offspring are female?
50%
Why does the male determine the sex?
The male carries a X and Y chromosome, the female only carriers X chromosomes.
Using Punnett squares determine how sex-linked traits are inherited. (R)
• Baldness is a recessive trait Is the mother bald?No
Is the father bald?Yes
Is the mother a carrier for baldness?No
What percent of female offspring will be bald?
0%
What percent of male offspring will be bald?
0%
Analyze a karyotype. (S)
What is this picture called?A karyotype
Is this a picture made from a male or female?
Male
Which chromosome pair are the sex chromosomes?
23rd pair
Pairs 1-22 are called?Autosomes
Does this person have a genetic mutation for Down’s syndrome?
no
Interpret a pedigree. (S)
What sex is represented by squares? MalesHow many children do the parents I 1 and I 2 have?5Red represents an individual with color blindness? Is person I 2 color
blind?NoIs person I 2 a carrier?Yes- it is the only way color blind female offspring are possible based on
her husbands genotype.