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Meiosis
Parents pass off their information to their offspring through the use of heredity units called
genes .
The locus is the location for a gene on a chromosome.
What is the difference between a somatic cell and a gamete?
A somatic cell is any cell that isn’t involved in gamete production, and it is diploid.
Gametes are reproductive cells that pass information to the next generation, and they are
haploid.
Autosomes determine an individual’s sex. True/False
In asexual reproduction, an individual reproduces by a making a clone or a genetically identical
individual.
Sexual reproduction results in offspring who differ genetically. True/False
What is a karyotype? How are homologous chromosomes related to the karyotype?
A karyotype is an ordered display of the chromosomes during mitosis. These chromosomes
are arranged in pairs according to their length, centromere position, and staining pattern.
These pairs are known as homologous chromosomes.
How many sets of chromosomes does a haploid individual have? A diploid individual? 1 set, 2
sets
Gametes are formed through the process known as meiosis .
Describe the difference in lifecycles between plants, animals, and fungi.
Animals- gametes are the only haploid cells, after meiosis gametes no longer divide until
fertilization, fertilization leads to a diploid zygote that divides until it is a multicellular
diploid organism.
Plants- have a alternation of generations, a multicellular, diploid sporophyte produces cells
that undergo meiosis to become haploid spores, the spores divide mitotically to became
haploid gametophytes that produce the gametes, the gametes will fuse to become the zygote
and produce the sporophyte
Fungi- gametes fuse to make a zygote that undergoes meiosis, haploid cells are produce
that divide mitotically to become multicellular
Describe the stages of Meiosis I and II.
Prophase I- chromosomes condense and homologs pair up, crossing over occurs while
homologs are in synapsis, centromeres move, spindle forms, nuclear envelope fades
Metaphase I- homologs are on metaphase plate, each chromosome kinetochore is attached
to a microtubule
Anaphase I- homologs separate and move toward opposite poles, sister chromatids stay
fused
Telophase I- no replication, cytokinesis may occur, each cell is now haploid
Prophase II- spindle forms, chromosomes move to metaphase plate
Metaphase II- chromosomes on metaphase plate, kinetochores of chromatids attach to
microtubules
Anaphase II- chromatids separate and move to opposite poles
Telophase II- nuclei reform, cytokineis occurs, 4 genetically unique daughter cells are
produced
Cohesin holds the chromosomes together during meiosis, and as the chromosomes separate
Separase breaks that compound down. To prevent sister chromatids from separating,
Shugosin protects the centromere.
What is the importance of genetic diversity?
It may allow populations to better survive changes in their environment, and it may
ultimately lead to evolution.