Unit #7: Meiosis Flashcards
Define genetics
Study of heredity and heredity variation
Define heredity
The generational passing of traits.
What is a locus?
A specific gene location on a chromosome
What is a homologous pair?
2 chromosomes of similar size and shape carrying the same genes.
What are some diplontic organisms and what makes them diplontic?
Humans, other animals, because we spend most of our lives as diploids and are only haploid when we are gametes.
What are some haplontic organisms and what makes them haplontic?
Fungi and protists, most of the time are haploid, only diploid when fertilized.
What are some diplontic organisms and what makes them diplontic?
Plants, because half their life they are diploid and half they are haploid.
What is the goal of Meiosis?
To reduce ploidy (diploid to haploid)
In G1, chromosomes have one chromatid, after DNA duplication, they have…
2!
What is a tetrad?
A pair of aligned homologous chromosomes.
In meiosis, we start with 1 diploid cell, we end with…
4 haploid cells.
What occurs in Prophase 1?
Chromosomes condense, tetrads come together and crossing over occurs.
What occurs in Metaphase 1?
Tetrads line up at the equator, spindle fibers attach to either side of the tetrad (1 per chromosome).
What occurs in Anaphase 1?
Spindle fibers shorten and the tetrad is pulled apart.
What occurs in Telophase 1?
Homologues are at opposite poles, chromosomes uncondense and cytokinesis occurs.
