Saturday, April 7, 2012

Gametes

Gametes are the reproductive cells in organisms. I can't remember if I mentioned this before but humans have 46 chromosomes, two copies of each one. Our last pair of chromosomes are our sex chromosomes, XX for females and XY for males. Gametes will contain one set of chromosomes. This is how we can pass down X-linked traits (which I will not elaborate on, in this post at least).

Source: http://legacy.owensboro.kctcs.edu/gcaplan/bio/notes/gametogenesis.jpg

This is a really good picture that describes how gametes are produced. First the cell must go through mitosis, which creates sister chromatids. It then enters meiosis I, where they separate into different cells, very similar to how mitosis works. Meiosis II then starts, and separates the sister chromatids once again. The difference between mitosis and meiosis is that the cellular yield is four haploid (containing one set of chromosomes) cells instead of two diploid (containing two sets of chromosomes) cells.

Answer to yesterdays question: Frederick Griffith died from a bomb dropping down in his laboratory (located in the back of his house if I remember correctly). The S strain of the bacteria Griffith used was deadly because it secreted a capsule that stopped the body's defense mechanisms, while the R strain did not. This meant that the body could easily fight the R strain but the S strain was deadly with no antibiotics.

I must apologize for the lack of commenting I've been doing. This is an extremely stressful weekend, but I WILL catch up either Tuesday evening or Wednesday morning! My genetics test is this coming Tuesday and I feel so unprepared.

5 comments:

A.D. Duling said...

Hi Jennifer!

Visited your blog here and love the post...you have been added to today's A.D.'s FAV 5 of the A to Z Challenge! Come lookie!!!!
http://adduling.wordpress.com/

A.D.

Hannah said...

Thanks for visiting my blog :) This post is really interesting! Love your blog

Su said...

What a cool series for A to Z! Gametogenesis is one of the few things I actually learned (meaning: I still remember) in my biology class. Good luck on your test!

Anita said...

Thanks for a very informative post :)

Jennifer Macfarlan said...

A.D. - Thanks! I will be sure to visit!

Hannah - Thank you for stopping over at mine!

Su - I'm glad you enjoyed my post!

Anita - Thank you for stopping by!