BIOL 11100 Lecture Notes - Lecture 4: Sister Chromatids, Egg Cell, Telophase

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sapphireelephant702

14 Apr 2016

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Document Summary

Same steps as mitosis, but chromosomes have been through crossing over. End product is four haploid cells, instead of the 2 that result from meiosis i. Disinguished from prophase i by lack of tetrads and from prophase by evidence of crossing over. Disinguished from metaphase ii by lack of tetrads, and from metaphase by evidence of crossing over. Spindle ibers are pulling chromaids apart and toward opposite poles. Disinguished from anaphase i by single chromaid, and from anaphase by evidence of crossing over. At cytokinesis, each daughter cell from meiosis i splits in two. Each new daughter cell is haploid, this ime with no sister chromaids. Each new daughter cell is unique- diferent from the others and from parent cell. Final result of meiosis is 4 haploid cells. Oogenesis: formaion of ova (eggs)- more complicated than spermatogenesis. Every division results in a iny, useless cell called a polar body.

Related Questions

Determine whether the following applies to mitosis, meiosis, orboth; also identify the specific stage of cell division thatapplies (e.g. mitosis prophase, meiosis anaphase II, etc)

1) chromosomes pairs line up across the center of the cell

2) sister chromatids seperate

3) spindle fibers separate homologous chromosomes

4) 4 haploid daughter cells are produced

5) a cell 1st undergoes DNA replication

6) chromosomes line up single file across the middle of thecell

7) sister chromatids separate from each other

8) 2 haploid daughter cells form

9) the nuclear membrane re forms

10) spindle fibers attach to pairs of homologous chromosomes

11) the nuclear membrane begins to dissolve

12) centrosomes duplicate

13) synapsis and crossing over occurs

14) 2 diploid daughter cells form

turquoiseporpoise808

-Complete the following sentences: metaphase of mitosis, prophase II of meiosis, crossing over, anaphase I of meiosis, variable, random fertilization, identical, random orientation, metaphase I of meiosis, prophase I of meiosis, metaphase II of meiosis, reduction division

Two processes that occur during meiosis produce genetically ____________ cells.

In a process called ____________ , paired homologous chromosomes align randomly at the cell equator. This occurs during this stage of cell division: ____________ .

In a process called ____________ , genetic material is exchanged between homologous chromosomes. This occurs during this stage of cell division: ____________ .

-Complete the following paragraph to describe nondisjunction and the resulting effects on chromosome number.

words: euploidy, primary nondisjunction, nomal, nondisjunction, secondary nondisjunction, homologous chromosomes, abnormal, trisomy, monosomy, sister chromatids, aneuploid

1.During meiosis I, ____________ separate and move towards opposite ends of the poles.

2.During meiosis II, ____________ separate and move towards opposite ends of the poles.

3.During meiosis I, if both members of a homologous pair go into the same daughter cell, ____________ is said to occur and no normal gametes are produced.

4.During meiosis II, if the sister chromatids fail to separate and both daughter chromosomes go into the same gamete, ____________ is said to occur. Half the gametes are aneuploid while the other half are euploid.

5.If an egg that contains 24 chromosomes instead of 23 chromosomes is fertilized by a normal sperm, ____________ is said to have occurred.

6.If an egg that contains 22 chromosomes instead of 23 chromosomes is fertilized by a normal sperm, ____________ is said to have occurred.

1) A tissue in a mouse contains two types of cells: one that divides rapidly and one that divides more slowly. The most likely difference between these two cell types is that the slow-dividing cell type spends more time in phase

G1, G2, G3, M, or S

2) In meiosis II

a- four genetically identical cells are generated

b- sister chromatids are separated

c- DNA replication occurs

d- crossing over occurs

e- both a and b

3) The four haploid nuclei found at the end of meiosis differ from one another in their exact genetic composition. Some of this difference is the result of?

a- cytokinesis