Meiosis 2 Quiz

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Meiosis 2 Quiz

Mieos 1 And 2

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what is meiosis?
  1. Meiosis is a process of nuclear division that reduces the number of chromosomes in the new cells to half the number in the original cell.
what is the prurpose of meiosis?  
  1. The purpose of meiosis is to form gametes with the haploid number of chromosomes.
what do cells preparing to divide undergo?
cells pre paring to divide by meiosis undergo the G1, S and G2 stages of interphase so the cell grow to mature size, and copies its DNA so it begins meiosis with a duplicate set of DNA.
what is one difference between meiosis and mitosis?
  1. The first major difference between meiosis and mitosis is that cells undergoing mitosis and the cells undergoing meiosis are that those undergoing meiosis divide twice.
how can meiosis be summarized?
  1. meiosis can be summarized as follows: you start with one cell and end up with 4 haploid cells that are not necessarily genetically identical to each other.
whay do varitations exist?
variations exist due to the farmation of a tetrad, synapsis, and crossing over.
what are 3 events that happen in prophase 1?
  1. The 3 events that occur in prophase I of meiosis that also occur in prophase in mitosis are that the chromatin coils up and becomes chromosomes, the nucleoli and nuclear membrane disappear, and the spindle begins to form.
what is a tetrad formed?
  1. A tetrad is homologous chromosomes of a pair that move toward each other and line up side by side.
what happens during synapsis?
during synapsis,
  1. the chromatids of the homologous pair twist around each other.
what happens during crossing over?
segments of the chromatids may break off and attach to an adjacent chromatid on the homologous chromosome pair.
what does crossing over cause?
  1. Crossing over causes an exchange of genetic material between maternal and paternal chromosomes resulting in cenetic recombination to occur.
what leads to genetic variation?
  1. Crossing over leads to genetic variation between all gamete that are produced.
what happens in metaphase 1?
the tetrads line up randomly along the equator.
what do the spindle fibers do in metaphase 1?
  1. the spindle fibers from one pole attach to the centromere of one homologous chromosome and spindle fibers from the other pole attach to the centromere of the other homologous pair of the chromosome.
What happens in anaphase 1?
Eahc homologous chromosme move to opposite poles .
what separates in anaphase 1?
What actually separates during anaphase I of meiosis is the chromosomes separate, not the chromatids.
what is independent assortment?
  1. Independent assortment is the randomness with which the tetrads line up and separate.
what does independent assortment lead to?
Independent assortment leads to additional genetic variation.
what happens in Telophase 1 and cytokenisis 1?
the chromosomes reach opposite poles and the cytoplasm divides
what do the daughter cells produced at the end of meiosis have?
  1. the daughter cells produced at the end of meiosis have only one chromosome of each homologous pair and are considered haploid.
what happens in prophase 2?
The spindle startes to form.
what happens in metaphase 2?
  1. In metaphase II of meiosis the chromosomes line up along the equator and one spindle fiber from one pole attaches to the centromere of one chromatid and another spindle fiber from the other pole attaches to the centromere of the other chromatid.
what happens in anaphase 2?
  1. In anaphase II the chromatids separate and move to opposite poles.
Waht happens in telophase 2 and cytokinesis 2?
  1. In telophase II and cytokinesis II of meiosis, chromosomes uncoil and become chromatin so the DNA can be read and proteins made, the spindle breaks down, the nucleolus reappars and a new nuclear membrane forms, cytokinesis separates the cytoplasm resulting in 4 haploid cells.
what are the final results of mieosis are?
The final result are 4 haploid cells that are not genetically identical
what is spermatogenesis is?
spermatogenisis is sperm production.
what happens in spermatogenesis?
  1. In spermatogenisis diploid cells within the testes undergo meiosis and produce cells called spermatids.
what does the cytoplasm determin in the number of functional gametes?
The division of the cytoplasm determines the number of functional gametes procuded because when the cytoplasm divides equally, the result is four functional haploid gametes
what do spermatids devolope into?
Spermatids develop into a mature sperm cell
what is oogenesis?
Oogenisis is egg production.
What happens in oogenesis?
  1. In oogenesis, dipoild cells in the ovaries undergo meiosis and produce 4 haploid cells.
what does the division of the cytoplasm determine in the number of functional gametes?
  1. The division of the cytoplasm determines the number of functional gametes procuded because the cytoplasm divides unequally and most of the cytoplasm goes to one cell.
what does the ootid devolope into?
  1. The ootid develops into the mature ovum.
why does the egg need extra cytoplasm?
  1. The egg needs the extra cytoplasm to meet its nutritional needs in case it is fertilized.
what are the other 3 cells called?
the three other cells produced by oogenesis are called polar bodies
what happens to the other 3 cells?
To these cells, they will eventually degenerate
what is reproduction?
  1. Reproduction is the process by which organisms make offspring of their own kind.
what are the two types of reproduction?
Asexual and sexual reproduction.
what is asexual reproduction?
  1. Asexual reproduction is the making of offspring without the union of special sex cells.
how many parents are involved in asexual reproduction?
  1. In asexual reproduction, the offspring comes from one parent.
how do the offspring and parent compare in asexual reproduction?
  1. The offspring that result form asexual reproduction compares to the parent because the offspring is genetically identical to the parent.
what is the first form of asexual reproduction?
Fission, it occurs when a unicellular organism replicates its genetic material and splits in two forming two new organisms. An example of this is bacteria and algae
what is the second form of asexual reproduction?
Budding, growth of a small reproductive fragment from a parent organism and an example is yeast.
what is the third form of asuexual reproduciton?
Spore, a spore is a reproductive cell that is covered by a hard coat and an example is molds and anthrax
what is the 4th form of asexual reproduction?
Vegetative propagation, is asexual reproduction in plants and an example is planting potato eyes, rooting systems and leaves, and runners on strawberry.
what is sexual reproduction?
  1. Sexual reproduction is the making of offspring through meiosis and the union of special sex cells called gametes.
what gametes does sexual reproduction require?
  1. The gametes involved in sexual reproduction and where each comes from are sperm which comes from the male and eggs from the female.
what is fertilization?
  1. Fertilization is when the gametes are haploid in chromosome number but the diploid number is restored during the fusion of the 2 gametes when the sperm combines with the egg forming a zygote.
what is a zygote?
  1. A zygote is the fusion of the 2 gametes when the sperm combines with the egg.
how are the offspring of sexual reproduction genetically different?
The 2 sources that make the offspring of sexual reproduction genetically different from their parents because genes are combined in new ways during meiosis.
what do all offspring of sexual reprduction contain?
they contain their oun unique genetic combination.
what do each gamete have?
each gamete has a unique combination and then combines with another gamete from a completely different genetic source.
what is the advantage of sexual reproduction?
  1. The type of advantage that sexually reproducing organism have over asexually reproducing is that it enables species to adapt rapidly to new conditions since some members may have a genetic difference that allows them to survive this change better than other members of species.
what is an example of this?
a dieseas that strikes a crop of grain.
what happens in the disease that strikes a crop of grain?
A few plants have a genetic varitation that makes them resistant to disease. although many plants die thouse few that are resistant survive, reproduce, and pass this resistance to their offspring.