Chapter 6 gentics

asexual reproduction

Asexual reproduction is a biological process in which an organism produces offspring from a single parent without the involvement of gametes or fertilization.

Sexual reproduction

Sexual reproduction is a biological process in which two gametes, fuse together to create a genetically unique offspring

State the differences in the cells that are generated in Meiosis and Mitosis

Meiosis produces four genetically unique daughter cells that each contain half the original number of chromosomes

Mitosis produces two genetically identical daughter cells that each contain the exact same number of chromosomes as the parent.

Apoptosis

Apoptosis is a programmed and controlled way for a cell to neatly "self-destruct" when it is no longer needed or is too damaged to function correctly.

Mutations

Mutations are caused by random errors in DNA replication or by environmental factors that damage the genetic code.

mutagen

A mutagen is any physical or chemical agent, such as radiation or certain toxins, that increases the frequency of these genetic mutations

Mutations may pass to future generations how

Mutations are passed down when a change occurs in the DNA of the sperm or egg cells used for reproduction.

Because the offspring grows from those specific cells, the mutation is copied into every cell of their body and can be passed to their own children.

Mutations are important, why

Mutations are important because they create genetic variety, which allows species to adapt to their environment and evolve over time.

homologous chromosomes

The matched pairs of chromosomes in a diploid organism

Genes

are the functional units of chromosomes that code for specific proteins to determine characteristics

locus

is the specific physical location where a gene is found on a chromosome

Traits

are the different forms of a characteristic

what causes variation w/i a species

The variation of individuals within a species is caused by the

specific combination of the genes inherited from both parents.

What is a mutation?

Any changes to a cells DNA sequence is a mutation

Cancer

uncontrolled division and growth of cells when the mechanisms controlling cell division have been destroyed

How does P53 work?

p53 is a protein that monitors DNA for damage and either pauses the cell cycle for repairs or triggers the cell to destroy itself if the damage is too permanent to fix

What controls cell division, what controls the cell cycle?

The cell cycle is controlled by cyclins and CDKs, which act as the signals to move forward, and checkpoints, which act as safety stops to ensure DNA is undamaged before the cell divides.

Write a paragraph on P53 using the following terms:

• Proto-oncogene

• Tumor suppressor gene

• Negative cell regulator

• Cell cycle checkpoints

• Apoptosis

P53 is a tumor suppressor gene which is a negative cell regulator. It controls the

cell cycle checkpoints by checking cells for damage and deciding if cell death or

apoptosis is needed. Tumor suppressor genes are usually in balance with Proto-

oncogenes.

What stages in meiosis can result in

changes in the nucleotide sequence vs

changing the number of chromosomes

in the resulting cells?

Nucleotide sequences are changed during Prophase I through crossing over, while the number of chromosomes is changed during Anaphase I or II through nondisjunction.

Cytokinesis

separation of the cytoplasmic components into two daughter cells

quiescent

(inactive) stage,