Meiosis CR 08 by Nicole DiClaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376 LO's 3.17-3.23 en-us 2020-11-11 01:48:15 UTC 2024-06-02 08:06:35 UTC hello@padlet.com Purpose of Meiosis 3.17 nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911206574 The purpose of meiosis is to get exactly one copy of each type of chromosome into daughter cell (Myhr, 2020) .

Meiosis occurs in humans in the gonads (ovaries and testis) to produce sperm and egg cells needed for reproduction. 

Meiosis uses diploid (2n or double the amount of chromosomes(a set from mom and a set from dad)) cells to produce haploid cells (n, number of chromosome types in a species).

During phase I the cell seperates a tetrad of sister chromatids in homogulous pair

During phase II the cell seperates the sister chromatids to produce cells that are haploid containing only one set of chromosomes from either mom OR dad.]]> 2020-11-11 01:49:51 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911206574 Fertilization 3.20 nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911207603 In humans, the sperm cells are deposited into the vagina from the penis. The sperm cells move through vagina, cervix, uterus, and fallopian tubes (oviduct) to find the egg cell in the ovaries.

Steps of Fertilization
1. Acrosomes break down the jelly coat that protects the egg cell. 
2. The sperm binds to species, specific recepters on the egg cell. This prevents the wrong type of sperm cell from fertilizing the egg.
3. The plasma membrane fuses.
4. The vitelline reaction occurs which is when the vitelline layers lifts away from egg to prevent other sperm from fertilizing. This ensures the correct ammount of chromosomes enter the cell.
5. The nuclei fuse together to form a blastocyst. 

The blastocyst moves down the oviduct to the uterus and implants itself to the uterine wall. This signals for the female to produce HcG which is the pregnancy hormone.]]> 2020-11-11 01:50:26 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911207603 Mitosis vs Meiosis I vs Meiosis II nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911230101 2020-11-11 02:03:26 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911230101 Prophase I nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911368370 The nuclear envelope disappears. Chromosomes condense, homologous tetrads come together. During this time there is a crossing over of nonsister chromatids. The microtubules emerge creating the mitotic spindle.]]> 2020-11-11 03:33:07 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911368370 Interphase nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911370893 The cell goes through G1, S, and G2 phases, duplicating chromosomes. 
In my recreation I have the chromosomes made of pipe cleaner in the middle of a green nuclear envelope. The centromosomes are at the top in purple.]]> 2020-11-11 03:34:53 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911370893 Metaphase I nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911373377 The tetrads align on the metaphase plate. The mitotic spindles (blue thread) pull on the kinetochores. The sister chromatids are joined together one same side of the cell while the homologous chromosomes are on opposites.

]]> 2020-11-11 03:36:42 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911373377 Anaphase I nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911378054 The cell elongates in preparation for division. Sister chromatids remain attached while homologous chromosomes separate. The spindles pull the sister chromatids to the poles on either side of the cell.]]> 2020-11-11 03:40:06 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911378054 Telophase I nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911380494 The chromatin sometimes uncoils. The mitotic spindles disappear and the nuclear envelope sometimes reforms. At the end, you will have two seperate cells. My picture depicts before cytokinesis has completed, showing the cleavage furrow.

]]> 2020-11-11 03:41:46 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911380494 Prophase II nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911387984 Similar to prophase I, the chromosomes condense if they werent already, sister chromatids are joined, mircotubules emerge making the mitotic spindles, and the nuclear envelope dissolves if there was one. This phase though, the homologous chromosomes are serparated into different cells.

]]> 2020-11-11 03:47:05 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911387984 Metaphase II nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911392021 Sister chromatids align on metaphase plate. The mitotic spindles pull on the kinetochores.]]> 2020-11-11 03:49:35 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911392021 Anaphase II nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911393730 The cell elongates to prepare for division. The sister chromatids seperate from the spindles pulling them to opposite poles of the cell.]]> 2020-11-11 03:50:40 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911393730 Telophase II nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911395487 The chromatin uncoils inside the newly formed nuclear membrane. The spindles disappear. Newly formed cells now only have one set of chromosomes. ]]> 2020-11-11 03:51:41 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911395487 STD's 3.21 nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911408529 The best way to prevent sexually transmitted diseases is abstinence. If you do engage in sexual activity, using a condom is effective in preventing STD's.

Bacterial Infections(can be cured with antibiotics) -
•Chlamydia
•Gonorrhea
•Syphilis

Viral Infections (not curable, but can be controlled) -
•Genital Herpes
•HIV
•HPV
(Myhr, 2020)
]]> 2020-11-11 04:00:02 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911408529 Birth Control 3.22 nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911408778 The best way to prevent unwanted pregnancy is abstinence.

If you are sexually active and do not want to become pregnant, other methods of birth control include:

•Birth control pill, patch or cervical ring - these produce HCG the pregnancy hormone into your body. Body does not produce an egg cell because it thinks it is pregnant. 
•Intrauterine device (IUD) - blocks sperm from being able to travel to oviduct to reach egg.
•Spermicides - kills or slows down sperm cells. 
•Latex condoms - prevents sperm from entering vagina after ejaculation.
•Sterilization - For women - "tubes tied" or causing a blockage at the oviduct so sperm cannot reach egg.
For men - the vas deferens is cut or blocked so sperm cannot enter the urethra. 
•Morning after pill - delays ovulation so no egg is present for fertilization

Forms of birth control that to do not include medical intervention
•Withdrawal - Removing penis from vagina during sex before ejaculation
•Rhythm method - Having sexual intercourse on days where the female is not fertile (during ovulation)

If a pregnancy has already occured
•Abortion - removal of embryo from uterus 

List adapted from Dr. Myhr's LO 3.22 Birth Control mini lecture on canvas. 
]]> 2020-11-11 04:00:11 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911408778 Pregnancy & Child Birth 3.23 nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911409278  After fertilzation, pregnancy goes through three stages of development which each last about three months.

First Trimester - Placenta, major organs and structures developing, moves from blastocyst to fetus.
Second Trimester - More development
Third Trimester - Major organs developed, baby grows big enough to sustain life otuside of womb.

Stages of Labor - 
Dialation - cervix opens in anticipation of passing baby.
Expulsion - Baby is delivered through uterine contractions pushing it out of vagina
Delivery of placenta - placenta detaches from uterine wall and is delivered through vagina, moved by uterine contractions]]> 2020-11-11 04:00:31 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911409278 Male and Female Reproductive Organs 3.19 nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911409927 The female reproductive system contains the vagina, cervix, endometrium, uterus, oviduct and ovaries. 
The vagina is the canal, which leads up to cervix.
The cervix is a group of muscles that pinch off the top of the vagina. Can be open or shut.
This leads into the uterus. 
The uterus has two tubes coming off of it, called the fallopian tubes, this is where sperm travels to reach the egg. 
Both tubes lead to your ovaries where the egg cell is waiting, after ovulation, for sperm.

The male reproductive system consists of the testis, vas deferens, urethra and penis. 
Sperm is produced in the testis which moves up through the vas deferens, small tubes that connect the testis to the urethra. The urethra is the the small tube in the penis that releases both sperm and urine. 

]]> 2020-11-11 04:00:55 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911409927 Summary and Reflection nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911411292 This week in an effort to boost my grade, I decided to step out of my power point comfort zone and try doing a padlet. I found the site easy to use. I like the ease of organizing my ideas into moveable boxes. After trying out a few different layouts I think this one best portrays my work.

Spending two weeks on mitosis and meiosis has given me a deep understanding of all the events that occur in order to produce new cell. It is amazing that this complicated of a progress is done daily in our bodies without knowing it. ]]> 2020-11-11 04:01:54 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911411292 References nicolediclaudio https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911416428  Myhr, Karen. LO 3.17 Why Meiosis. November 2020, https://canvas.wayne.edu/courses/132057/files/7768880/download?wrap=1
Myhr, Karen. LO 3.18 Meosis I. November 2020, https://canvas.wayne.edu/courses/132057/files/7775493/download?wrap=1
Myhr, Karen. LO 3.18 Meiosis II. November 2020, https://canvas.wayne.edu/courses/132057/files/7775692/download?wrap=1
Myhr, Karen. LO 3.19 Repro System November 2020, https://canvas.wayne.edu/courses/132057/files/7777501/download?wrap=1
Myhr, Karen. LO 3.20  Fertilization November 2020, https://canvas.wayne.edu/courses/132057/files/7779469/download?wrap=1
Myhr, Karen. LO 3.21 STD's . November 2020, https://canvas.wayne.edu/courses/132057/files/7779597/download?wrap=1
Myhr, Karen. LO 3.22 Fertility . November 2020, https://canvas.wayne.edu/courses/132057/files/7779787/download?wrap=1
Myhr, Karen. LO 3.23 Preg Birth . November 2020, https://canvas.wayne.edu/courses/132057/files/7804010/download?wrap=1]]> 2020-11-11 04:05:28 UTC https://padlet.com/nicolediclaudio/7x3fkxz5hfioh376/wish/911416428