Section 10 Genetics & Evolution TyAnthony Jones Biology 6th

10.1 Meiosis

Chromosome Replication U1: Chromosome replicate in interphase before meiosis.

The Exchange of dna material U2- Crossing over is the exchange of DNA material between non-sister homologous chromatids

Chiasmata formation U4- Chiasmata formation between non-sister chromatids can result in an exchange of alleles

Prophase 1 Crossing over occurs during Prophase one of mitosis

Homologous chromosome separation U5- Homologous chromosomes separate in meiosis I.

Sister chromatid separation U6- Sister chromatids separate in meiosis II.

Independent assortment of genes U7- Independent assortment of genes is due to random orientation of homologous chromosomes pair in meiosis 1

New combinations of alleles U3- Crossing over produces new combinations of alleles on the chromosomes of the haploid cells

10.2 Inheritance

Linkage Groups U1 Gene loci are said to be linked if on the chromosome.

Linkage Groups and Separation U2 Unlinked genes segregate independently as a result of meiosis

Variation U3 – Variations can be discrete or continuous

Variation U4 – The phenotypes of polygenic characteristics tend to show continuous variation Polygenic characteristics rely on more than one allele to alter the phenotype.

Chi-squared test U5 – Chi-Squared tests are used to determine the difference between an observed and expected frequency distribution is statistically significant.

10.3 Gene pools and speciation

Gene pool and allele frequency U1- A gene pool consists of all the genes, and their different alleles, present in the interbreeding population.

Evolution U2 – Evolution requires that allele frequencies change with time in populations

Reproduction isolation of species U3 Reproductive isolation of populations can be temporal, behavioral, or geographic

Directional, stabilizing, and disruptive isolation U4 Speciation due to divergence of isolated populations can be gradual As shown in the image, the changes in morphology gradually changed as time progressed. This can be done by small changes instead of drastic changes.

Speciation U5 Speciation can occur abruptly As shown in the image, the changes in morphology took a small amount of time to change.

Bibliography "Brent Cornell." Meiosis. Web. 22 Apr. 2016. "BioCoach Activity." Pearson. Web. 22 Apr. 2016. "Dihybrid Crosses and Gene Linkage." Dihybrid Crosses and Gene Linkage. Web. 22 Apr. 2016. "The Sea Shore - FSC (Field Studies Council)." The Sea Shore - FSC (Field Studies Council). Web. 22 Apr. 2016.