BIO EXAM 2

• -independent assortment of chromosomes
• -crossing over
• -random fertilization

1. Alternative versions of genes account for variations in inherited characters. ex:allele

2. For each character, an organism inherits two alleles, one from each parent.

3. If two alleles at a locus differ, then one(the dominant allele) determine's the organism's appearance, and other(the recessive allele) has no noticeable effect on appearance.  ex: F1 plant had purple flowers b/c allele for the trait is DOMINANT

4. (NOW.K.A. law of segregation) The two alleles for a heritable character separate (segregate)during gamete formation and end up in different gametes... thus egg or sperm get one of two alleles present in organism...this corresponds to distribution of homologous chromosomes to gametes in meiosis 

• States the probability that two or more independent events will occur together is the product of their individual probabilities.
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• Probability in F1 monohybrid cross can be determined through this.

having two different alleles for a given gene

having two identical alleles for a gene

Haploid reproductive reproductive cell, such as egg and sperm. Unite to make diploid cells.

Individuals that are heterozygous for one character

Cross between heterozygotes

Crossing two true-breeding parents differing in two characters produces this. f1 are both heterozygous

• A cross between F1 dihybrids
•  -can determine whether 2 characters are transmitted to offsrping as a package or independently

states that probability that any one of two or more exclusive events will occur is calculated by adding together their individual probabilities.

this can be used to figure out probability that an F2 plant from a monohybrid cross will be heterozygous rather than homozygous

occurs when phenotypes of the heterozygote and dominant homozygote are identical

the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties.

two dominant alleles affect the phenotype in separate, distinguishable ways

• deletion
• duplication
• inversion
• reciprocal translocation

Fruit fly

• Convenient b/c:
•          -produce many offspring
•          -generation can be bred in 2 weeks
•          -have only 4 pairs of chromosomes

because females have XX sex chromosomes while males have XY sex chromosomes.

Total number of recombinants (non-parentals) divided by total number of progeny

Fatal; dysfunctional enzyme causes an accumulation of lipids in the brain

• multiple phenotypic effects
• -responsible for multiple symptoms of some hereditary diseases like cystic fibrosis and sickle cell disease