Chapter 1- Intro to Genetics

What is genetic heterogeneity?

A situation in which the same phenotype may result from variation in several different genes.

How many types of albinism is there?

4 types

Albinism Role in Farming?

Does not have one!

What does MELANIN do?

Protects skin DNA from UV radiation in sunlight & important in function for eye development

Albinism occurs in how many?

1 in 20,000 individuals

Albinism in Hopis: Why is prevalence higher?

Have advantages in mating

what is in Hopis?

type 2, oculocutaneous albinism OCA2 gene on chromosome 15. 

What are the 4 environmental influences that we discussed previously?

• Mutagens

• Gene-gene interaction

• Transcription

• Epigenetics (smoking)

what is the fundamental problem in genetics?

separating the genetics and environmental influences on individual variation

• you always want to look at if it is the gene or environment causing phenotype

What are the 3 divisions of genetics?

• Transmission Genetics

• Molecular Genetics

• Population Genetic

Transmission Genetics answers what question?

What are you getting from mom/dad?

Molecular Genetics answers what question?

What is in your DNA?

Population Genetics answers what question?

What does our population look like?

Explain Transmission Genetics

• A.k.a. classical genetics

• Encompasses the basic principles of heredity and how traits are passed from one generation to the next. This subdiscipline addresses the relation between chromosomes and heredity, the arrangement of genes on chromosomes, and gene mapping.

Explain Molecular Genetics

• Concerns the chemical nature of the gene itself: how genetic information is encoded, replicated, and expressed. 

• It includes the cellular processes of replication, transcription, and translation (by which genetic information is transferred from one molecule to another) and gene regulation (the processes that control the expression of genetic information). 

• Molecular genetics focuses on the gene's structure, organization, and function.

Explain Population Genetics

• Explores the genetic composition of populations (groups of individuals of the same species) and how that composition changes geographically and over time. 

• Because evolution is genetic change, population genetics is fundamentally the study of evolution. 

• The focus of population genetics is the group of genes found in a population.

Give all the characteristics of model organisms:

• Short generation time (short time to have kids)

• Production of numerous progeny (as many possible)

• Ability to carry out and control genetic crosses in the organism

• Ability to be maintained in a laboratory with minimum space and resource requirements (need less resources/space)

• Availability of numerous genetic variants

• Body of knowledge about their genetic systems

What is Pangenesis?

Genetic information from different body parts travels to the reproductive organs, where it is transferred to the gametes.

• The concept is proven to be incorrect.

Why do you think all organisms use nucleic acids for encoding genetic information?

All organisms use nucleic acids for encoding genetic information due to their chemical stability, efficient information storage, and ability to support accurate replication and translation processes. Additionally, this system has been conserved through evolution from a common ancestral origin, making it a fundamental and universal mechanism of life.

Hereditary- how traits are transferred:

• Preformationism (body just grows)

• Blending Inheritance B+Y=G

• Pangenesis (travels across the body)

• Inheritance of acquired characteristics

Why not use proteins or carbohydrates?

Proteins and carbohydrates lack the structural and functional properties necessary for stable and precise information storage and transfer, making them unsuitable for this role.

What advantages might DNA have as the source of genetic information?

DNA is the source of genetic information because it is very stable, can be copied accurately, and can store much information in a small space. It also has built-in ways to fix mistakes, making it reliable for passing on information for generations.

Early Concepts of Heredity: Pangenisis

Genetic information travels from different parts of the body to reproductive organs

• INCORRECT CONCEPT

Early Concepts of Heredity: Inheritance of Acquired Characteristics

Acquired traits become incorporated into hereditary information

• INCORRECT CONCEPT

Early Concepts of Heredity: Preformationism

Miniature organism resides in sex cells, and all traits are inherited from one parent

• INCORRECT CONCEPT

Early Concepts of Heredity: Blending Inheritance

Genes blend and mix

• INCORRECT CONCEPT

Early Concepts of Heredity: Germ-plasm Theory

All cells contain a complete set of genetic information

• CORRECT CONCEPT

Early Concepts of Heredity: Cell Theory

All life is composed of cells, and cells arise only from cells

• CORRECT CONCEPT

Early Concepts of Heredity: Mendelian Inheritance

Traits are inherited in accord with defined principles

• CORRECT CONCEPT

What were ZEBRA FISH used for?

Have been used to study pigmentation and identify genes that affect skin pigmentation in humans.

What are model organisms used for?

to study aspects about ourselves

who is the father of genetics?

Gregor Mendel

Define Genome?

the complete set of DNA/RNA in an organism

• Genetic instructions of organisms

• DNA connects all organisms past and present

• For example studying how bacteria DNA is replicated provides information on DNA replication of other organisms

What are the FUNDAMENTAL CONCEPTS in genetics?

• Prokaryotic vs Eukaryotic cells

• Gene is Fundamental unit of heredity and are located on chromosomes

• Chromosomes separate during mitosis and meiosis

• Genes come in multiple forms called alleles and many traits are affected by multiple genes and environmental factors

• Genes confer phenotypes

• Genetic information is carried in DNA and RNA

• Mutations are permanent and can be inherited

• Evolution is Genetic change

who recognized that heredity was fundamental to evolution?

Charles Darwin

Define Evolution?

the genetic change over time and requires understanding of genetics

• Inherited differences

• Variations due to evolutionary change

What is the Engrailed Gene responsible for?

segmentation of the fly embryo

What is the Green Revolution?

1950s and 1960s to expand food production relied on genetic methods and principles

Food & Animal Manipulation—> CORN!

What did people practice genetics for thousands of years on?

Animals & Plants

Why does the “Golden Mutant Zebrafish” have light pigmentation?

due to the presence of fewer, smaller, and less dense pigment containing structured called melanosomes in cells.

The theory of preformationism proposed that inside of the egg or sperm is a tiny, fully formed adult called the _____.

homunculus