BISC 101 Lecture Notes - Lecture 25: Spermatocyte, Oogenesis, Spermatid

41 views3 pages

plumant882

25 Jun 2017

School

Simon Fraser University

Department

Biological Sciences

Course

BISC 101

Professor

Ivona Mladenovic

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

Document Summary

To describe spermatogenesis and oogenesis: spermatogenesis: process of creating the sperm cells. Mitosis: 1 diploid spermatogonium divides by mitosis, producing 2 diploid primary spermatocytes, some 3 million spermatogonia differentiate into primary spermatocytes each day. Meiosis i: primary spermatocyte (diploid cell) undergoes meiosis i, which reduces the chromosome number by half producing secondary spermatocytes (haploid cells, 1 primary diploid spermatocyte produces 2 haploid secondary spermatocytes (with duplicated chromosomes) Meiosis ii: 1 haploid secondary spermatocyte (with duplicated chromosomes) produces 2 haploid spermatids in the process of meiosis ii, spermatids develop into haploid sperm, oogenesis: process of creating the eggs, completion of meiosis i and onset of meiosis. Unequal cytokinesis occurs: large cell will eventually become the egg (ovum) and the small cell becomes a polar body. Both are haploid: this is the cell that ovulated, then meiosis stops again! Secondary oocyte is arrested at metaphase of meiosis ii: a sperm is needed to induce secondary oocyte to complete meiosis ii.

Related Questions

13. Meiosis differs from mitosis in that:
a. meiosis results in the production of two new cells, whilemitosis results in the production for four new
cells., b. meiosis is used for growth and repair, while mitosis isused for production of eggs and sperm., c.
cytokinesis can be unequal following meiosis, but is approximatelyequal following mitosis., d. meiosis
involves one cell division, while mitosis involves two celldivisions., e. meiosis results in the production of
diploid cells, while mitosis results in the production of haploidcells.
14. Bits of maternal and paternal chromosomes are exchanged betweenhomologous chromosomes during
synapsis of meiosis I. This process is called:
a. crossing over., b. random mating., c. random fertilization., d.random shuffling of parental
chromosomes.,
e. mutation.
15. The advantage of sexual reproduction over asexual reproductionis that:
a. all young are genetically identical to the parent., b. malesmust evolve a copulatory organ., c. genetic
variability in the population is increased., d. females must evolvea vagina., e. mates are not needed.
16. Many different types of information are used to constructphylogenetic trees. Which of the following types
of information is the most direct measure of evolutionaryrelatedness?
a. physiology, b. gene sequence data, c. the fossil record, d.information about the structure of ribosomes.,
e. information about the structure of enzymes
17. A species is:
a. a group of individuals that can interbreed under naturalconditions and produce fertile offspring., b.
denoted by both a genus and a species name., c. the onlybiologically defined taxon., d. a group of
organisms with a large number of traits in common., e. all of theabove.
18. The process of spermatogenesis results in:
A. 4 diploid sperm; B. 1 diploid sperm and 3 haploid polar bodies;C. 1 haploid sperm and 3 haploid
polar bodies; D. 4 haploid sperm
19. Which cell division process results in an unequal division ofthe cytoplasm?
A. Spermatogenesis; B. Testiculargenesis; C. Oogenesis; D. None ofthe above
20. Meiosis is the process by which:
A. 1 diploid cell becomes 4 haploid cells; B. 1 diploid cellbecomes 1 haploid cell and 3 haploid polar
bodies; C. 1 haploid cell becomes 4 diploid cells; D. Both A andB
21. The phase of mitosis where chromosomes line up at the equator(middle) of the cell is called:
A. Anaphase; B. Telophase; C. Interphase; D. Metaphase
22. Chromosome #6 from Mom and Chromosome #6 from Dad form achromosome pair called:
A. Sister Chromatids; B. Centromeres; C. Homologous Chromosomes; D.Spindle Apparatus

scarlethare433

-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.

BISC 101 Lecture Notes - Lecture 25: Spermatocyte, Oogenesis, Spermatid

Document Summary

Get access

Related Documents

BISC 101 Lecture Notes - Lecture 12: Seminiferous Tubule, Spermatocyte, Spermatogenesis

BISC 101 Lecture Notes - Lecture 15: Pollen Tube, Megaspore, Microspore

Related Questions