Unit 5 - Genetics & Biotechnology Study Guide Flashcards
Explain the Meiosis Cycle
Interphase - Cell grows, DNA replication
Prophase I - DNA coils into Chromosomes, homolougous chromosomes cross-over, Centrosomes move to poles and spindle fibers form
Metaphase I - Chromosomes line up at Metaphase plate and attach to spindle fibers
Anaphase I - Spindle fibers pull chromosomes to centromeres
Telophase I - Nuclear membrane forms, chromosomes uncoil, and cytokinesis forms two cells
Prophase II - DNA coils in chromosomes, centrosomes move to poles and spindle fibers form
Metaphase II - Chromosomes line up at Metaphase plate and attack to spindle fibers
Anaphase II - Spindle fibers pull chromatids to centromeres
Telophase II - Nuclear membrane forms, chromosomes uncoil, and cytokinesis forms two cells
Gregor Mendel
Austrian monk who studied pea plants to see how traits passed. Used:
- Controlled pollination - used a paint brush to control which 2 plants reproduced
- Cross pollination - plants usually self pollinate = they have male and female parts
→Stated that certain “factors” called genes, control traits of the pea plant
Principle of Segregation
when producing sex cells, each sex cell gets 1 of 2 alleles for a trait (ex. Rr; sex cell either gets R or r)
Principle of Independent Assortment
genes for different traits seperate independently from each other
(ex. Rr and Yy seperate into R, r, Y, and y; can combine 4 different ways)
Polygenic traits vs. multiple allelic traits vs. sex-linked traits (with examples)
Polygenic Traits - Traits with large variety controlled by genes located on multiple chromosomes (ex. eye color, hair color, skin color, human height)
Multiple Allelic Traits - traits controlled by 2 alleles; 3+ versions of trait results (ex. human blood types A, B, AB, O)
Sex-Linked Traits - traits controlled by the sex chromosomes (colorblindness, hair ears, hemophilia)
DNA Fingerprinting notes
Use: Paternity determination determine crime suspects body identification
- only identical twins have same DNA sequences
- can make more copies of DNA using PCR (Polymerase chain reaction) so that the original DNA is not damaged or destroyed
Causes + Symptoms of Sickle Cell Anemia, Cystic Fibrosis & Huntington’s
Sickle Cell Anemia
Cause: both incomplete and codominance = abnormal + normal shaped red blood cells
Symptoms: clogged blood cells
Cystic Fibrosis
Cause: recessive genetic disorder
Symptoms: mucus buildup in lungs
Huntington’s:
Cause: dominant gene disorder
Symptoms: slow death of brain cells, coordination issues; fidgety movements
Recombinant DNA (rDNA)
DNA made by connecting, or recombining, fragments of DNA from different sources
Charles Drew
Black physician who established blood banks at Colombia University- seperating blood cells from plasma allowing blood to be stored, longer up to a week.
Steps of Gel Electrophoresis
1. Restriction Enzymes: one or several restriction enzymes are added to a sample of DNA. The enzymes cut the DNA into fragments.
2. The gel: gel is molded so that small wells form at one end. Small amounts of the fragmented DNA are placed into these wells.
3. Electric Field: Gel is placed in a solution and an electric field is applied making one end of the gel positive and other end negative.
4. Fragments move: Negatively charged DNA fragements travel toward the positive end; smaller the fragment, the faster it moves through the gel and away from the well
Gene Splicing
splice in new desirable genetic information that gets passed onto offspring
Benefits of rDNA
1 - insulin produced by E. Coli bacteria
2 - used for anti-viral drug protection
3 - vaccine protection
4 - alter plants to resist cold, drought, etc…
Therapeutic Cloning vs Reproductive Cloning
Therapeutic Cloning: Produces stem cells for tissues
Reproductive Cloning: Produces whole organism
Types of Cloning
- Vegatative propogation - a sexual reproduction without variation
- Grafting - tissues of plants are joined to grow together
- Whole organism - exact copy of organism
Primary problem in bacterial transformation
Both Plasmid DNA and plasma membranes of the E. coli bacteria contain phosphate groups so there both negatively charged (-) and repell each other. Researchers use calcium chloride to neutralize the negative charges.
Types of Plant + Animal Breeding
- Controlled breeding - breading organisms with certain traits to get desirable outcome (ex. larger tomatoe)
- Mass selection - crossing PLANTS with desirable traits for many generations until offspring show traits consistently
-
Cross Breeding/inbreeding - breeding closely related organisms (ex. purebread dog)
- increases strengths of certain traits
- certain diseases with inbreeding
- inability to adapt to environmental changes
- Hybridization - 2 genetically different organisms are crossed resulting in hybrids that have charateristics of both; usually healthier (ex. donkey + horse = sterile mule)
