Chapter 13 Things you should know!

Asexual vs. Sexual reproduction Genes are segments of DNA that code for the basic units of heredity. (They are also a great addition to any wardrobe) Locus = location of a gene on a chromosome

Asexual vs. Sexual reproduction Asexual reproduction produces genetically identical offspring through mitosis, they are called clones. Sexual reproduction produces offspring who receive half of their genetic material from each of their parents. This creates greater genetic variation.

Meiosis and fertilization These both play an important role in creating genetic variability. Meiosis reduces the number of chromosome sets from diploid to haploid. This creates genetically diverse gametes. Fertilization adds variation to the mix by joining together two genetically diverse gametes.

Homologous Chromosomes Homologous chromosomes allow for an allele of every trait to be contained in the haploid daughter cells.

Meiosis: diploid to haploid

Mitosis and meiosis: the differences Synapsis and crossing over generally only occur in Meiosis At metaphase I, homologous chromosomes line up in the center of the cell. At anaphase I, homologous chromosomes separate as opposed to the chromatids separating in mitosis.

Crossing Over Creates four unique sister chromatids

Independent assortment of chromosomes Creates a 50% chance that a particular daughter cell will get a maternal or paternal chromosome from the homologous pair.

Random fertilization Each combination of sperm and egg is unique.