Unit 2: Genetic Processes Review
1. DNA is important to the human body because it provides the instructions for life. It is an
instruction maual that builds and contains all the information in our bodies. Without it,
everyone would look the same and so, it is responsible for making individuals.
2. DNA is a biolgical moelcule called a nucleic acid. 3 smaller molecules make up DNA which
include Deoxyribose sugar, Phosphate and the Nitrogenous bases of Adenine, Thymine,
Cytosine and Guanine. It contains all the information of life and is shaped like hexagons.
3. Base pairing is the rungs that are made up of 2 of the nitrogeneous bases bonded together,
which follow the pattern of A always bonding with T and C always bonding with G. A stands
for Adenine, T stands for Thymine, C stands for Cytosine, and G stands for Guanine.
4. A nucleotide is made up of 3 parts, 1 sugar, 1 phosphate and 1 nitrogeneous base. These can
beany nitrogeneous base along with sugar deoxyribose and any phosphate group.
5. The Human genome project has allowed the development of genetic tests to screen for genetic
diseases. We can see DNA mutations in genes and therefore identify problems, which is huge
in creating the future medicine and cures for human dieases and mutations.
1. Somatic cells are body cells while gametes are sex cells. Gametes are found only in
reproductive organs and each have 23 chromosomes. Somatic cells have 46 chromosomes and
are found anywhere in the body other then in the sex cells.
2. Gametes are the egg and sperm cells in our body, each consisting of 23, a haploid number. In
order for reporduciton to take place, the gametes must come together, so when the haploid
sperm and the haploid egg are fused, they fuse to get a diploid number, which is a fertilized
zygote. This also ensures variation and that the daughter cells do not receive two complete sets
of chromosomes. Insetead, the daughter cells should grow through mitossi to beomce diploid.
Somatic cells are diplod because they have 2 sets off 23 chromosomes. Each daughter cell gets
two complete sets of chromosomes and this produces 2 cells that are identical to the mother
3. The cell cycle has 2 main stages, growth and division. The growth stage is called interphase
and the division stage is both Mitosis and Cytokinesis. In Interphase, the G1 phase is
responsible for growth and preparation. The S phase is next, and it allows for DNA
synthesis(copying DNA). Lastly, the G2 phase is responsible for the preparation for division. Next comes mitosis, where it is Prophase, Metaphase, Anaphase and Telophase. Prophase is
when the chromatin coil up to form chromosomes. The spindle fibres begin to form and the
nucleur membrane vanishes. Lastly, the centrioles migrate to opposite poles. In Metaphase, the
spindle fibres attach to the chromsomes and allign on the equatorial plate(middle). The sister
chromatids face opposite poles. In Anaphase, the centromere on the chromosome splits and the
sister chromtids are pulled to opposite poles by the spindle fibres. Finally, in Telophase, the
nuclear membrane forms around the chromatids and the spindle fibres disappear and the
chromatids decondense to chromatin. In Cytokinesis, the cytoplasm divides and forms 2
daughter cells. Both of these cells contain a diploid number of chromosomes.
4. Mitosis occurs so that there is growth(cell division allows for growth), repair(cuts), and
maintenance(replace dead cells).
5. Mitosis consists of