Week Review 1: Genes!!!

Hey 7th graders- this is the first week review. Now, blog entries will not be daily, but weekly, so you have to check at the beginning of the week. Anyway, here is what we did in 7th Grade Science this very short 3 day week:
Monday: (No School- President's weekend).
Tuesday: We talked about Skye and Poppy, and their offspring. We learned that each parent gives one gene to their offspring. We also learned about dominant and recessive traits. A dominant trait is the one that basically has 'more say'. For instance, if the dominant trait is blue, and the recessive trait orange, and if you have one blue and one orange trait, you would get a blue [tail]. See SmartNotes and "Critters Template" for more info.
Wednesday: More genes (see above).
Thursday: Punnentt Squares, see SmartNotes and "Punnett Squares--Step by Step" handout for more information.
Friday: (No School- Snow Day!)

TERMS YOU NEED TO KNOW
Alleles: Versions of a trait
Phenotype: Physical characteristics that are visible
Genotype: Genetic information (alleles) for a given trait.
Homozygous: same alleles
Heterozygous: different alleles

That's all for this week! *See SmartNotes for more information!

Sexual and Asexual Reproduction

Organisms that reproduce asexually are usually single-celled organisms, such as bacteria, while sexually reproducing organisms are multicellular organisms such as humans.


In sexual reproduction - two parents are required, offspring inherit genetic material from both parents - which creates diversity among a species.


In asexual reproduction - only one parent is needed, which makes the reproductive rate much quicker, and an asexually reproducing organisms does not need a mate.

Mitosis and Meiosis

More new terms! Gamete, Diploid Cells, Haploid Cells, Gonads, Testes, Ovaries, Sperm Cells, and Egg Cells!

What is Mitosis? It is the process when one cell makes an exact copy of itself (clone), it does this by copying its chromosomes before dividing into two identical daughter cells. In humans and other multicellular organisms, mitosis is used to create new cells for repair of the body (example - new skin cells for healing.. new bone cells etc.)

What is Meiosis? It is the process when one cell creates 4 haploid cells (sex cells) that are all genetically different. The sex cells contain half the number of chromosomes of every other cell in the body. The sex cells created by the male testes is called the sperm cell. The sex cells created by the female ovaries is call the egg cell. In sexually reproducing organisms, an egg cell will be fertilized (united) with a sperm cell to create a zygote containing the full number of chromosome (46 for a human cell)


Important places to look.... Act 57 Copycat, Meiosis and Mitosis flash file, Meiosis and Mitosis powerpoint diagram.

Intro To Genetics

We have started our genetics unit - covering the basic understanding of the structure and importance of DNA. Many new and important vocabulary terms were introduced. These terms include the following;

DNA
Chromosomes
Genes
Base Pairs (AT and CG)
Autosomes (Chromosomes 1-22 in Humans)
Sex Chromosomes (XX = Girl, XY = Boy)
Proteins

The Tour of the Basics Flash file is incredible important to review!