Friday, March 18, 2011

Mr. Finley's class blog- 3-18-11

Egg cell....................................
sperm cell....................................

Happy friday everyone!!!! Tonights the dance!!!! (just reminding everyone, lol). So now onto science. Our homework was to read the questions on mr. finleys homework page and then write the answer in our notebooks or on the computer. These were the questions:

1. If an egg and sperm cell merge, what can you say about the amount of chromosomes each must have?
It must be 50% percent of chromosomes from each cell (egg and sperm) when they merge so that the daughter cell can have 100% of their chromosomes.

2. How does this relate to a homologous pair of chromosomes? (same kind)
Sara attemped but failed at the answer. It's ok, Sara! she said that half come from the mom and half from the dad chromosomes, but Mr. finley objected. Homologous pairs pair by 2's. He explained this on the board. HALF of your homologous pair comes from the mom (chromosomes), HALF of your homologous pair comes from the dad. Good save, Sara! Once again, a homologous pair is two chromosomes that have the same trait. Chromosomes determine how you look, like your physical traits.

3. Could we start with a normal cell, go through mitosis, and end up with an egg or sperm cell? why not?
No this is not possible. You cannot just get a skin cell to produce a egg cell out of nowhere. Plus, cells can only produce cells that are the same kind as them. When we split two skin cells, we need them to have 100% percent of chromosomes for the two new daughter cells to have 100% of the chromosomes as well. But when we have a sperm and egg cell, we need them to have 50% so when they merge, they will create 100% percent for the new cell.

-----------------------------------------------------------------------------------------------

After this, we began reading an article on meiosis. It talked about how flowers are still producing sexually because they self-pollinate and also how diferent mammals and plants reproduce asexually and sexually. Some key terms are:

Haploid- Repeoductive cells containing half of a parent'c chromosomes.


Zygote- Combined sperm and egg cell


Fertilization- process of sperm fertilization of the cell




By the way, Mr. finley added that sexual reproduction and sexual intercoarse are NOT the same thing. (awkward, yes, but nessicary!!)




Now today, (monday) mr finley is away and now we are working on a venn diagram and also a meiosis activity. See you tomorrow Mr. Finley!!!!!!!!!!!!!!!!!!!




That's all!!!!




- Caroline S. (best student ever) :D
- caroline s :D

No comments:

Post a Comment