BIOL 1000 Lecture Notes - Lecture 10: Sister Chromatids, Meiosis, Mendelian Inheritance

55 views5 pages

fuchsialouse995

23 Nov 2017

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Metaphase i: variability at recombination and actually at the midpoint in metaphase. How many possible combinations: move to opposite poles, diversity is huge. Combination of gametes in fertilization: anaphase ii sister chromatids being separated, telophase ii is where we have the gametes, separating the tetrads sister chromatids are still together. Human sex chromosomes: putting it all together into one offspring determination. Mistakes in meiosis: separation can not occur properly = non disjunction, chromosome that was suppose to stay in the cell but gets pulled to other side of cell. Non-disjunction during meiosis i: extra chromosomes and missing chromosomes, gamete with extra and missing chromosome all together, if missing in gametes cant be used for offspring. Non-disjunction during meiosis ii: everything was fine in meiosis i and then end up with level of non disjunction at meiosis ii, we would have two regular gametes. Non-disjunctions and sex chromosomes: at any chromosome and sex chromosomes, when offspring produce can have problems.

Related Questions

Part A- Microtubules. Select all that apply.

1) They are filaments in mitotic and meiotic spindles

2) They are required for moving sister chromatids to opposite sides of the poles during anaphase II of meiosis and anaphase of mitosis.

3) They are required for moving homologs to opposite sides of the poles during anaphase I of meiosis.

4) They are important for maintaining homologous chromosome pairing and plays a role in recombination.

5) They catalyze the phosphorylation of specific proteins.

6) They are a layered structue located between paired homologs in prophase I of meiosis in many organisms.

Part B- Cyclin-dependent kinases. Select all that apply.

1) They are filaments in mitotic and meiotic spindles.

2) They are enzymes that control progression through cell cycle.

3) They are required for the segregation of chromosomes during anaphase of mitosis or meiosis.

4) They are important for homologous chromosome pairing and plays a role in recombination.

5) They catalyze the phosphorylation of specific proteins.

Part C- Kinetochores. Select all that apply.

1) They are enzymes that control progression through cell cycle.

2) They are important for maintaining homologous chromosome pairing and plays a role in recombination.

3) They are required for the segregation of chromosomes during anaphase of mitosis or meiosis.

4) They are complx structures attached to the centromeres of chromosomes that bind to spindle microtubules.

5) They catalyze the phosphorylation of specific proteins.

Part D- Synaptonemal complex. Select all that apply.

1) It is required for moving sister chromatids to opposite sides of the poles during anaphase II of meiosis and anaphase of mitosis.

2) It is a layered structure located between paired homologs in prophase I of meiosis in many organisms.

3) It is complex structures attached to the centromeres of chromosomes that bind to spindle microtubules.

4) It catalyzes the phospohorylation of specific proteins.

5) It is important for maintaining homologous chromosome pairing and plays a role in recombination.

Which of the following statements are true. CHALLENGEQUESTION:

a. In meiosis, the chromosomal material doubles during the lastpremeiotic interphase.

b. The greater the number of chromosome pairs, the greater isthe effect of meiosis in producing genetically distinctgametes.

c. The diploid number of chromosomes is half the haploidnumber.

d. A cell that will not divide again remains in the GÂ2 stage ofinterphase.

e. The correct sequence of events during meiosis is: synapsis âdyad formation â chiasma formation

f. In an organism with n = 3, there is a 1 in 8 probability of agamete with all maternally derived chromosomes contributing to theproduction of a zygote.

g. An organism with n = 3 can produce 8 different kinds ofgametes in relation to combinations of maternal and paternalchromosomes.

h. Separation of sister chromatids occurs during anaphase I ofmeiosis and is the physical basis for the law of independentassortment.

i. A single diploid cell that undergoes meiosis in the maletestis will produce 4 genetically different gametes ifcrossing-over is ignored.

j. The independent alignment of different tetrads at metaphase Iof meiosis is the physical basis of the law of independentassortment.

k. If a diploid cell has 20 pairs of chromosomes, there will be10 tetrads during prophase I of meiosis.

l. If a diploid cell has 20 pairs of chromosomes, there will be20 bivalents during prophase I of meiosis.

m. If a diploid cell has 20 pairs of chromosomes, there will be80 chromatids present during metaphase of mitosis.

n. If a diploid cell has 20 pairs of chromosmes, the organismcan make 20² types of gametes if crossing-over isignored.

o. Segregation of sister chromatids occurs during anaphase I ofmeiosis and is the physical basis of the law of segregation.

p. For an individual with a diploid number of 30 chromosomes,there will be 60 chromatids at metaphase I of meiosis.

q. For an individual with a diploid number of 30 chromosomes,there will be 15 tetrads at metaphase II of meiosis.

pinksalmon285

Which of the following statements are true. CHALLENGE BIOLOGYQUESTION PLEASE EXPLAIN IF POSSIBLE: