Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. What are the main events
    of the second mitotic period?


The second mitotic period is metaphase.


In metaphase thoccur: condensed chromosome following eventses bind (in (^)
their centromere region) to the spindle
fibers and get concentrated in middle of the cell; the formation theof the (^)
mitotic apparatus is completed.
Metaphase enthe binding of identical chromatids ads with the breaking ofnd (^)
then anaphase begins.



  1. What are the main events
    of the third mitotic period?


The third mitotic period is anaphase. In


anaphase duplication athe followinnd breaking g events occur:of centromeres (^)
with separation of identical chromatids;
traction (identical chromatids eacby the spindle fibers) ofh to opposite (^)
cell poles; beginning of chromosome
decondensation.



  1. During mitotic anaphase is
    there separation of
    homologous chromosomes or
    separation of identical
    chromatids?


In the anaphase of mitosis the identical
chromatidsof homologous chr separate omosomes coand complete pairsntinue
to exist in each daughter cell. The


separation ochromosomes occurs if the homologousn the anaphase o (^) f
the cell division by meiosis.



  1. What are the main events
    of the final mitotic period?
    The final mitotic phase is telophase. In


telophase decondensation othe followinf chromg events occur:osomes, eac (^) h
set located in opposite cell poles;
karyotecchromosomes fha formatioorming two nn around each set ofuclei;
destruction of the mitotic apparatus;
reappearing of the nucleoli; bcytokinesis (the division of cytoplasm toeginning of
ultimately separate the new cells).



  1. What is the name of the
    cytoplasm division in the end
    of mitosis? What are the
    differences in this process
    between animal and plant
    cells?


Cytoplasm division occurs afttelophase and it is called cytokinesis. Iner (^)
animal cells an invagination of the
plasma membrane toward thcenter appears in the equator ofe cell the (^)
parent cell and then the cell is
strangulated into two daughter cells. Tin that region and dividedhis type of
division is called centripetal cytokinesis
(from outside).
In plant cells the cytokinesis is not
centripetal since from the inside. Membranous sacs full ofthe division happens (^)
pectin concentrate in the internal central
region of the cell anperiphery toward the plasmad propagate to the
membrane. The pectin-containinfuse themselves and form a centralg sacs
structure called phragmoplast. On the
phragmoplastoccurs and a true cell wall cellulose deposition is created (^) to
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