Biology A Final - DNA & Mutations

Pt. 1

DNA Structure

Found in the cell's nucleus as chromatin. When the cell is ready to divide, the chromatin coils up into chromosomes

Ex. Adenine with Thymine, and Cytosine with Guanine

DNA Function

Store and transmit genetic information that provides instructions for an organism's growth, development, reproduction, and cell functions

Gene

Section of DNA that codes for a protein/trait

Ex. Adenine, Thymine, Cytosine, Guanine and Phosphate, Deoxyribose Sugar, and Nitrogenous Base

Deletion

Whole region of chromosome is deleted

Duplication

Whole region of chromosome is duplicated

Inversion

Regions of chromosomes are swapped

Translocation

Genes on homologous chromosomes are swapped

RNA Structure

Single-stranded molecule made of nucleotides

Ex. Adenine, Uracil, Cytosine, and Guanine

RNA Function

Help make proteins by carrying and using the genetic instructions stored in DNA

Transcription

Process of making an mRNA copy of a DNA segment in the nucleus using the enzyme RNA polymerase. The mRNA then moves to the cytoplasm

Translation

When mRNA is read by tRNA to create an amino acid chain (polypeptide chain) which turns into proteins

Codon Wheel

Mutagen

Substance or factor that causes changes (mutations) in DNA

Gene Mutations

Affect one gene

Chromosomal Mutations

Affect more than one gene

Homologous Chromosomes

Pairs of chromosomes—one from each parent—that are similar in size, shape, and gene locations, but may carry different versions of the same genes

Karyotyping

Process where a person’s chromosomes are arranged and examined in pairs to look for changes in number or structure

Amniocentesis

Medical test where a small sample of amniotic fluid is taken from the uterus to check a baby for genetic disorders or chromosome abnormalities

Chorionic Villi Sampling

Prenatal test where a small sample of cells from the placenta (chorionic villi) is taken to check a developing baby for genetic or chromosome abnormalities

Ultrasound

Medical imaging technique that uses high-frequency sound waves to create pictures of structures inside the body, such as a developing baby during pregnancy

Diploid

Cell has two sets of chromosomes, one set from each parent

Somatic Cells

ll the body cells except sex cells (sperm and egg), meaning they have two sets of chromosomes

Cancer

Disease where cells grow and divide uncontrollably, forming abnormal masses called tumors and potentially spreading to other parts of the body