Meiosis & Independent Assortment
These chromosomes carry the same sequence of genes but not necessarily the same alleles.
What are homologous chromosomes?
A cross involving two traits is called this.
What is a dihybrid cross?
The specific location of a gene on a chromosome is called this.
What is a gene locus?
Genes that are close together on the same chromosome are described as this.
What are linked genes?
This statistical test is used to determine whether observed results differ significantly from expected ratios.
What is the chi-squared test?
This phase of meiosis I is when homologous chromosomes line up randomly at the equator.
What is metaphase I?
The expected phenotypic ratio of a dihybrid cross between two heterozygotes for unlinked genes is:
What is 9:3:3:1?
The SRY gene is located at this locus.
➡️ What is Yp11.2?
This process during meiosis can separate linked alleles and create recombinant gametes.
What is crossing over?
The null hypothesis states that observed and expected values are this.
Not significantly different
Mendel’s second law states that alleles of different genes assort independently during this cellular process.
What is the law of independent assortment?
The expected phenotypic ratio of a test cross between a heterozygote (RrYy) and a homozygous recessive (rryy) is:
What is 1:1:1:1?
The SRY gene encodes this type of polypeptide product.
A DNA-binding protein that initiates testis development?
In a test cross involving linked genes, the most common offspring phenotypes are these.
What are parental (non-recombinant) types?
Degrees of freedom are calculated using this formula.
What is n − 1?
Independent assortment only applies when genes are located on these structures or are far enough apart to recombine at 50%.
What are different chromosomes (or far apart on the same chromosome)?
In a test cross, the purpose of crossing with a homozygous recessive individual is to reveal this.
What is the genotype of the unknown (or whether alleles assort independently)?
Gene loci begin with the letter or number of this structure.
The chromosome on which the gene is located?
In a linked gene test cross, the least common offspring phenotypes are these.
What are recombinant types?
If χ² is smaller than the critical value (7.815 at df = 3, p = 0.05), we accept this hypothesis.
What is the null hypothesis?
Explain why the movement of homologous chromosomes in anaphase I leads to independent assortment of unlinked genes.
What is the random segregation of homologous chromosomes separating allele pairs independently into gametes?
If a dihybrid cross does not produce a 9:3:3:1 ratio, one possible explanation from your slides is:
What is gene linkage (or non-independent assortment)?
Why might two genes located very close together on the same chromosome fail to assort independently?
Because they are linked and inherited together during meiosis
If a test cross produces significantly more parental phenotypes than recombinant phenotypes, this suggests:
The genes are linked?
If χ² is greater than the critical value in a dihybrid cross, what biological conclusion can be drawn?
The alleles are not independently assorted and the genes may be linked