Studied by 3 people
Genotype
The set of genes an organism has
Phenotype
The set of traits an organism expresses
What are the benefits of sexual reproduction
The offspring are more genetically diverse
Diploid
Having 2 sets of chromosomes (2n)
Haploid
Having a single set of chromosomes (1n)
Homologous chromosomes
Chromosomes similar in size and shape
Karyotype
A visual display of condensed chromosomes
Synapsis
When the homologous chromosomes line up gene for gene.
What is the exception to synapsis
Xy chromosomes which line up at their tips only.
When does synapsis occur
In prophase I, when the centromeres migrate.
Crossing over
Occurs during the synapsis. The maternal and paternal homologs cross at points called chiasma. Genetic material is exchanged between non sister chromatids.
Recombinant chromatids
Chromatids that have exchanged genetic info and now have a new combination of genes.
What separates during Anaphase I?
Homologous chromosome, but not sister chromatids.
What does meiosis I result in?
2 genetically different, haploid daughter cells.
What’s the difference between prometaphase I and II?
In PM I, the spindles attach to the kinetochore on both sides of each chromosome. In PM II, the spindles attach to the kinetochores on opposite sides of the chromosome.
What separates during meiosis II?
Sister chromatids
What does meiosis II end in?
4 genetically different, haploid daughter cells.
What happens when gametes fuse?
They become a diploid zygote.
Oocyte
The larger, haploid cell produced by females.
What happens as male daughter cells develop into sperm?
They lose cytoplasm and become smaller.
How does fertilization contribute to genetic diversity?
It pools together the genes of two unique individuals.
Allele
Variations of gene
Mono hybrid cross
A cross between 2 organism that are heterozygous for one trait
Law of segregation
Half of the daughter cells inherit the maternal allele, the other half inherit the paternal allele
Addition rule of probability
Probability of mutually exclusive events
P(A or B) = P(A) + P(B)
Multiplication rule of probability
Independent events
P(A and B ) = P(A) * P(B)
How do you determine the degree of freedom of a chi square?
One less than the number of categories.
What is the threshold value for the chi square and what does it mean?
0.05. We will only incorrectly reject the null hypothesis 5% of the time
Incomplete dominance
The heterozygous genotype exhibits a phenotype that is a mix of the homozygous dominant and recessive.
Codominance
Both alleles are expressed in a heterozygous organism.
Law of independent assortment
Alleles for one gene sort independently from the alleles of another gene
Pedigree
A visual map of phenotypes in a family
How is a dominant trait expressed in a pedigree.
It’s present in every generation but not necessarily in every individual.
What proof could we use to say that a gene is on an auto some?
The males and females are equally as likely to have it.
What pattern does a recessive trait follow in a pedigree?
It usually skips one or more generations. Affected individuals may also have unaffected parents.
Incomplete penetrance
An individual does not express the phenotype that their genotype codes for.
Variable expressivity
Phenotype appears in all individuals with the genotype but the degree of expression is different.
