TOPIC 4 - GENETICS (REGENTS)

Cancer

Occurs when certain genetic mutations in a cell can result in uncontrolled cell division. It can be caused either by heredity or environmental factors like radiation, chemicals or virus

Heredity

The passing of genetic information from one generation to the next through reproduction

DNA organization

Hereditary information in the form of genes located in the nucleus of each cell

Asexual reproduction

• Identical cells

• 1 parent

• little genetic variation

• EX: Ameba, paramecium, fungi

• MITOSIS

Sexual reproduction

• Not identical cells

• 2 parents

• much genetic variation

• much genetic variation

• EX: Humans, plants

• MEIOSIS & Fertilization

Clones

Identical genetic copies

DNA

A double stranded helix polymer of nucleotides that contains the genetic code of the individual

Nucleotide

The basic unite of DNA which made of a phosphate, a sugar, and a base

DNA bases

A, T, G, C

(All Teachers Go Crazy)

RNA

• Single stranded polymer that is produced by DNA

• 3 types: Messenger, transfer, & ribosomal

RNA bases

A, U, G, C

(No T in this base code rule)

Protein synthesis

DNA is stuck in the nucleus, so it send a messenger single - stranded mRNA to the ribosome where the ribosome reads the message and directs the tRNA (TRUCKS) to bring it Amino acids. The ribosome then assembles the amino acids together in the correct order to make a protein

Mutation

Any alteration of the DNA sequence which changes the normal message carried by the gene

Substitution

One base is put in place of another

Deletion

A base is left out (deleted)

Addition

A base is added

Inversion

Bases are switched

Gene expression

An organism’s environment can affect the way that some genes are expressed.

(EX: Himalayan rabbits’ fur color is influenced by temperature)

Genetic engineering

A technology that humans use to alter the genetic instructions in organisms

Gene splicing

Cutting DNA using restriction enzymes and placing it into another organism

(EX: Putting the gene for insulin into bacteria, and the bacteria produced insulin for humans)

Restriction enzyme

An enzyme that cuts DNA in specific places and is an essential tool in gene splicing as well as in gel-electrophoresis

DNA fingerprint

From gel electrophoresis, just like a barcode. The more common the bars, the more common/closer the heritage, or ancestry.

Selective breeding

A process of picking parents with favorable traits to produce those traits in the offspring.

(EX: Domestic animals and hybridization of plants)

Species

A group closely related organisms that share certain characteristics and can produce offspring capable of reproduction