U Got It! Flashcards
(45 cards)
where are genes found in the body?
they are sections of DNA; genes carry our genes
how are traits related to genes?
chromosome in DNA, gene in DNA, gene contains instructions for making proteins, the complex of proteins equals traits
single gene disorders
are rare, recessive allele
Sex linked(x-linked) inheritance
involves genes on X chromosome
whether a male or female, it affects the pattern of inheritance
Ex. Red-green color blindness: due to recessive gene on X chromosome( light sensitive cells in the eyes don’t unction properly)
-Male pattern baldness: Gene is on X chromosome passed from mother to son and since its recessive a female needs 2 chromosomes with the defect to show male pattern baldness
Chromosome abnormalities
chromosomes don’t separate during gamete formation
Ex. Abnormal number of chromosomes, missing or duplicated segments of chromosomes
Trisomy21 is Down syndrome: an extra chromosome 21(3)
Multi Factorial Inheritance
changes in multiple genes, environmental factors interaction of many genes
Many genes = traits
how environmental factors influence our traits
ex. nutrition, exercise, sunlight, chemicals= skin color etc.
- They all change your traits without altering your DNA
- Environmental factors change gene expression
Epigenetics
Changes in expression of genes (not DNA itself) DNA modified by chemical “tags” or “switches” on your genes- can change the way your DNA is expressed- Changes in your traits *DNA sequence not changed**
Ex. diet, behavior, where you live
DNA structure
macromolecules made up of nucleotides double helix (double stranded) 4 kinds of bases (ATCG) A-T; C-G
Flow of DNA, RNA, Protein
DNA Carries directions for an organism, directions copied from DNA into RNA in the nucleus(Transcription), RNA travels to the cytoplasm where it directs the assembly of proteins(Translation)= Amino acid: Protein
Transcription
Copying instructions from DNA into RNA in the nucleus
Translation
The RNA travels to the cytoplasm where it directs the assembly of proteins(chains of amino acids) in cytoplasm
mRNA
1st step to make a copy of the gene
Codons
three letter words; 3 single letter pairs= 1 amino acid
Ribosome(chef)
Reads the sequence of RNA bases; each amino acid is brought to the ribosome by tRNA and is connected to the growing chain of amino acids
Protein Synthesis
Chain of amino acids twists and folds into the elaborate structure that is characteristic of that protein; once FOLDED the protein can function
Function: Body Structure, Regulate Body Functions(enzymes, hormones) seldom used for energy.
DNA, Genes, Proteins, Traits Relationship
Genes are in DNA which make proteins that can express traits
What are mutations?
Any change in DNA
2 general ways to alter DNA
- Change one or more DNA bases
- Move entire sections of DNA from one place to another
DNA mutations in Evolution
mutations are important for genetic variation and evolution
Ex. In dif populations of dairy farmers, Genetic mutations keep lactase active throughout life
Lactose Intolerance
Most humans stop producing lactase after adolescence; lack digestive Enzyme(lactase) that breaks down sugar to break down lactose
Cancer Cell Characteristics
- Abnormal Shape
- Not Specialized
- Immortal(can divide continually) Uncontrolled Cell Division
- caused by breakdown in the normal checkpoints that regulate cell division
Causes of cancer
- Mutations that damage DNA
- Environmental carcinogens
- Tobacco smoking
- x-rays
- UV Radiation in sunlight and tanning lamps
- Some viruses
- HPV virus
- Heredity
- Diet
Can mutated genes be inherited?
Usually not; most mutations occur in the organ where the cancer starts, egg and sperm cells aren’t affected and are not passed from parent to child
** but cancer- causing mutations sometimes occur in gametes
