Chapter 13- Meiosis and Sexual Life Cycles Flashcards
What is asexual reproduction?
Creates clones that are identical to each other and the parent cell, involves mitosis.
True or false: asexual reproduction is less efficient than sexual reproduction.
False, it rapid and efficient
How do bacteria reproduce?
binary fission
How does sexual reproduction work?
gametes fuse to form a zygote
What is the process of halving the number of chromosomes called?
meiosis
What are somatic cells?
any cell that is not involved in reproduction, they are diploid
What are the partners of a chromosome called?
homologous chromosomes
how many total chromosomes are in humans?
46
What are polypoid cells?
when cells have extra sets of chromosomes (3n or more)
True or false: Polypoid cells are fatal in animals but common in plants
True
What happens in Meiosis 1-Prophase 1
Chromatin condenses into chromosomes and homologous chromosomes pair together
What is the result of meiosis 1-prophase 1
tetrad, 4 total chromatids
What is crossing over/genetic recombination?
when genetic material is exchanged between chromatids
In meiosis 1-prophase 1, what are sister chromatids held together by?
centromeres
What happens in meiosis 1-metaphase 1?
tetrads line up along the midplane of the cell
What happens in Meiosis 1-Anaphase 1?
homologous chromosomes separate and move toward opposite poles
What happens in Meiosis 1-Telophase 1?
mitotic spindle fibers disintegrate, chromosomes partially decondense, and nuclear membranes can form around genetic material
What is interkinesis?
the period between meiosis 1 and 2
What happens in Meiosis 2-Prophase 2?
chromatin partially decondense after Meiosis 1
What happens in Meiosis 2 - Metaphase 2?
chromosomes line up at midplane of cell, sister chromatids are connected by kinetochores
What happens in meiosis 2 - anaphase 2?
sister chromatids segregate toward opposing poles
What happens in meiosis 2 - telophase 2?
mitotic spindle fibers disintegrate, chromosomes decondense, cytokinesis can now occur
what are spores?
produced from meiosis divide via mitosis to form a haploid gametophyte
what are mutations?
alternations in nucleic acid sequence
True or false: All mutations are bad
False
What is Muller’s Ratchet?
asexual populations tend to accumulate harmful mutations by chance over time, with no good way of eliminating them
what is DNA repair?
many species reproduce sexually only during times of stress
What is the red queen?
sex allows for populations to “store genetic diversity” so that it is available for each generation
