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His mother, (X chromosome with the recessive allele)
A carrier is someone who has one recessive allele. You would need to look at their parents and/or their offspring. If any of their offpsring show a recessive trait then you know each of the parents must carry the allele even if they don't show it.
A carrier is also heterozygous for that trait.
Squares are males and circles are females
The diploid number is the number of chromosomes in a cell with two sets of chromosomes; has two sets of each gene; present in body cells (somatic cells)
0% for all children; 100% of females will be carriers; and none of the males will carry the trait or show the trait. XBXb, XBY
75%. Hh, HH, hh
Y chromosomes do not usually carry sex linked genes.
Genotypes: Bb, BB
Phenotypes: 0% blue; 100% brown
Heterozygous means the individual is a hybrid, or that they are carrying a dominant and recessive allele.
A heterozygote may also be called a "carrier" since they carry an allele that is not shown.
Homozygous means that they have two of the same allele, both dominant or both recessive.
The haploid number is the number of chromosomes in a cell with a single set of chromosomes; present in gametes (sex cells) only; half of the diploid number.
When looking at a pedigree analysis, how do you determine if someone is a carrier?
What do the terms heterozygous and homozygous mean?
Cross a heterozygous blue eyed female with a homozygous brown-eyed male. Brown is dominant to blue. List the possible genotypes and their percentages. List the possible phenotypes and their percentages.
What does the diploid number mean and which cells are diploid?
If a male child has the allele for baldness, a sex-linked trait, which parent did he inherit the allele for baldness from?
Why does the "Y" allele for males not need an "exponent"?
Huntington's Disease is caused by a dominant allele (H). What is the likelihood of the children having this disorder if both parents are heterozygous? List the genotypes.
If a bald man has a child with a woman that does not carry the baldness allele, what are the chances that their child will be bald? List all possible genotypes.
What do the different shapes in a pedigree analysis represent?
What does the haploid number mean and which cells are haploid?
| Description | Match: |
| List the stages of mitosis in order. | Prophase, Metaphase, Anaphase, Telophase |
| What is a karyotype? | A karyotype is a photograph of chromosomes. |
What does the diploid number mean and which cells are diploid? | The diploid number is the number of chromosomes in a cell with two sets of chromosomes; has two sets of each gene; present in body cells (somatic cells) |
What does the haploid number mean and which cells are haploid? | The haploid number is the number of chromosomes in a cell with a single set of chromosomes; present in gametes (sex cells) only; half of the diploid number. |
| How does meiosis contribute to genetic variability? | Meiosis increases genetic variability by separating homologous chromosomes into individual gametes during Meiosis I and through the process of crossing over during Prophase I |
| What is the principle of dominance? | Alleles can be recessive or dominant. Dominant alleles are always expressed. |
| What is an allele? | Alleles are the different forms of a trait (e.g., blue, brown, or green eyes) |
| What is the principle of segregation? | Alleles separate into different gametes during meiosis |
| Why does a recessive trait disappear and then reappear in future generations? | Recessive traits can be carried but not shown. Future generations may have homozygous recessive combinations resulting in the reappearance of a "lost" phenotype. |
| What is the difference between phenotype and genotype? | Phenotypes are traits that can be physically observed. Genotypes are the "genes" that determine your physical appearance; invisible to the observer. |
| What is the purpose of a Punnett Square? | Geneticists create Punnett Squares to predict the future genotypes and phenotypes of individuals. |
What do the terms heterozygous and homozygous mean? | Heterozygous means the individual is a hybrid, or that they are carrying a dominant and recessive allele.
A heterozygote may also be called a "carrier" since they carry an allele that is not shown.
Homozygous means that they have two of the same allele, both dominant or both recessive. |
Cross a heterozygous blue eyed female with a homozygous brown-eyed male. Brown is dominant to blue. List the possible genotypes and their percentages. List the possible phenotypes and their percentages. | Genotypes: Bb, BB Phenotypes: 0% blue; 100% brown |
| Sickle Cell Anemia is a recessive disorder symbolized by "a". What is the likelihood a child will have the disorder if both parents are heterozygous for the disorder? List all possible genotypes. | 25% of children with the disorder. AA, aa, Aa |
Huntington's Disease is caused by a dominant allele (H). What is the likelihood of the children having this disorder if both parents are heterozygous? List the genotypes. | 75%. Hh, HH, hh |
| What is a sex linked trait? | A sex linked trait is carried on the sex chromosomes ONLY. Usually on the X chromosome. |
| What symbols should be used for the games in a Punnett Square for sex-linked traits? | XX, XY; Each X should have an "exponent" to show the allele that is being carried. |
Why does the "Y" allele for males not need an "exponent"? | Y chromosomes do not usually carry sex linked genes. |
If a male child has the allele for baldness, a sex-linked trait, which parent did he inherit the allele for baldness from? | His mother, (X chromosome with the recessive allele) |
If a bald man has a child with a woman that does not carry the baldness allele, what are the chances that their child will be bald? List all possible genotypes. | 0% for all children; 100% of females will be carriers; and none of the males will carry the trait or show the trait. XBXb, XBY |
What do the different shapes in a pedigree analysis represent? | Squares are males and circles are females |
| What does a shaded shape in a pedigree analysis represent? | Shaded shapes represent an individual that is affected by the gene of interest. The affected allele may be dominant or recessive. |
| If a daughter has a different phenotype than her parents, what is her genotype? | She must be homozygous recessive |
| Why are females more likely to be carriers of a recessive sex linked trait? | Because the X chormosome carreiers many traits that can be passed down to female offspring, but they will not show the trait unless the father also contributes a recessive trait on the x chromosome. If a male carriers a recessive sex linked trait, he will be showing it. |
When looking at a pedigree analysis, how do you determine if someone is a carrier? | A carrier is someone who has one recessive allele. You would need to look at their parents and/or their offspring. If any of their offpsring show a recessive trait then you know each of the parents must carry the allele even if they don't show it.
A carrier is also heterozygous for that trait. |
