Ceniya Jefferson
Genetics
Prof. Thoma
08-20-2024
Chapter I
Introduction to Genetics
(How do Genes Influence Lives)
Gene - A portion of a chromosome
Genetics - Study of heredity
- They are fundamental to who and what we are. From the phenotype to the DNA makeup.
- Genes affect the susceptibility to many diseases and disorders
- ^Can be mutated and deformed
- Altercations appear in some cases during the sequence, such as deletion or addition
- Genes are importance because they code for proteins, enzymes, etc., that have the jobs of
development
Genotype - Anything happening at the genetic level
Phenotype - Anything happening at the protein level
Genome - A complete set of genetic instructions for any organism
Either RNA or DNA
- Coding system for genomic information very similar among organisms
(Chromosomes)
- 23 pairs form each parent to make up 46.
- Genomic DNA is the genome
- The three domains of life: Arkaea, bacteria, and Ukarea, all use DNA as their genetic
material
- The exception: Viruses - Some use RNA and some use DNA, they are not living
- If it’s living, it has a DNA Genome
(Reading a Genome)
Transcription & Translation - The same in all organisms
(Division of Genetics: Lens)
Transmission genetics
- AKA Classical genetics or study of heredity
- One generation to the next
- Genotype and phenotype
- Phenotype - Any observable trait (Animals: Jaguars like to hunt by themselves)
, - Chromosomes (circular) are in bacteria & (linear) in eukaryotes such as dogs, cats,
humans, plants, etc.
- Focused on the individual organism
Molecular genetics
- Concerns chemical nature of genes
- How information is encoded onto the gene, replicated, and expressed
- The structure and organization of genes
- Alleles - different forms of the same gene
Population genetics
- Genetic composition of groups of individuals of the same species (population) and how
that composition changes over time and space. Fundamentally, the study of evolution.
(Humans, animals, etc.)
- Change in allele frequencies
- Example : Horses, can be living or die off for a population change and have a different
gene set
Where is Meiosis Found? In Eukaryotes, reproductive cells
- Meiosis I and II is strictly for sex cells and to generate mass variation in offspring
- Mitosis is for every other cell
Chapter 1, Part I
What is Genetics?
- The study of heredity, how inherited traits are passed, encoded, replicated, and changed over
time.
- Genes can see where it’s placement is and what is can/will produce or not
- For diseases, such as disatrasphic dysplasia, it’s through the chromosomes. On chromosome 5,
it’s a defeat in the gene that caused the diseases.
- It was the understanding of genetics, Norman Borlaug, he was the leader in the Green
revolution. He figured out how to feed massive populations through genetics. He studied rice
plants and high yield, reducing stress on citizens by being able to produce more food.
Unifying Principles?
- All organisms use genetic systems
, - A complete set of genetic instructions for any organism=genome
- Common to all organism/ encoding(RNA & DNA), copying (Replication), decoding
(Amino Acid)
- One system and apply to another system
- When encoding, it’s using nitrogenous bases (Nitrogen and chemical bases (pH 7+) and
nucleotides (Nb’s attached to sugars)/ nucleoside (base only, sugar only)
Common Characteristics of Model Organisms ?
- Organisms that help understand genetic variation/mutation
- Typically short variation time for faster results
- Numerous proganies, data sets
- Ability to control genetic crosses
- Grow, or keep alive in a laboratory
- Generic variance
Ex: Fruit fly, ecoli, yeast Time: Roundworm, nematode, rabbit dobsis, mouse
(Concept Check 1)
What are some implications of all organisms having similar genetic systems?
A. That all life forms are genetically related.
B. That research findings on one organism’s gene function can often be applied to other
organisms.
C. That gene from one organism can often exist and thrive in another organism.
D. All of the above.
(Concept Check 1)
All organisms share a common coding system for their genomic information. The common
features of heredity imply all the following, EXCEPT that
A. All life forms on Earth share a common ancestor.
B. The study of one organism’s genes typically reveals principles that apply to other organisms.
C. All organisms will have the same number of genes.
D. Genes from one organism will often function in another organism.
E. None of the above implication of a shared coding.
(Concept Check 1)
Which of the following are characteristics a model genetic organism should have?
A. Has a slow generation time.
B. Has easily defined characteristics.
C. Has a little progeny.
D. Requires highly technical equipment to be studied.
, E. Is easily studied outdoors.
(Concept Check 1)
Which of the following subdisciplines of genetics focuses on how an individual organism
inherits and passes on its genes to the next generation?
A. Transmission genetics.
B. Molecular genetics.
C. Agricultural genetics.
D. Population genetics.
(Concept Check 1)
August Weismann cut off the tails of mice for 22 consecutive generations, yet in each
generation all the descendants were born with long tails. His experiment demonstrated that
A. Acquired characteristics are not heritable.
B. Sex cells carry a complete set of genetic information that is passed to offspring.
C. The mice must have produced “tail gemmules” before their tails were cut off.
D. The tail length is not genetically determined
E. Both A & B are correct.
F. Both C and D are correct.
Chapter 1, Part II
History
- 10,000-12,000 years ago
- Ancient theories of genetics often came from the Greeks
Pangenesis, incorrect
- Each part of the body contains genetic information for that particular part
- Specific particles=gemmules carry info from parts of the body to the reproductive organs
- Info passed to the embryo at the moment of conception
- Charles Darwin
Inheritance of acquired characteristics, mostly incorrect (epi genetics) theory
- Traits acquired in a person’s lifetime become incorporated into that person’s hereditary
information
- Traits are passed on to offspring
Preformationism, ancient theory, incorrect
- Inside the egg or sperm exists a fully formed miniature adult
- Simply enlarges in the course of development
Blending Inheritance, incorrect theory
- Traits of offspring are a blend, or mixture, of parental traits
- After “blending” the individual traits are not recovered in future generations
