Test 1 Flashcards
How is genetics important to individuals? (1.1)
• genes influence our lives
• genes contribute to personality
• genes are fundamental to who and what we are
How is genetics important to society? (1.1)
• genes are important in agriculture
• major crops and animals have undergone genetic alteration to increase yields and provide desirable traits
• develop and mass-produce substances
How is genetics important to a biology student?
To understand:
1. Evolution
2. Developmental biology (tissue and organs develop thru expression of genes
3. Taxonomy, ecology and animal behavior
What is a genome?
Complete set of genetic instructions for any organism
What encodes a genome?
Either DNA or RNA
When is a genome copied?
During process of replication
How does genetics relate to evolution?
Coding for genetic information is the same in ALL living organisms. Soo all organisms are thought to have evolved from a common ancestor
What are some implications that all organisms have similar genetic systems?
- all life forms are genetically related.
- research findings on one organism’s gene function can often be applied to other organisms
- Genes from one organism can often exist and thrive in another organism
What is transmission genetics?
• how traits are passed from one generation to the next
• parent to offspring
• FOCUS on individual organisms
What is molecular genetics?
• chemical nature of the gene
• how genetic info is encoded, replicated, and expressed
• FOCUS: the gene/genome and its structure, organization, and function
What is population genetics?
• the genetic composition of populations (gene pools)
• how gene pools change geographically and with time
• FOCUS: genes and frequencies of their alleles found in a population NOT on individuals
What are model genetic organisms?
Organisms with characteristics that make them useful for genetic analysis
What are the 6 commonly used model organisms?
- Drosophila melanogaster (fruit fly)
- Escherichia coli (bacterium)
- C. elegans (nematode)
- Arabidopsis thaliana (Thale-cress plant)
- Mus musculus (house mouse)
- Saccharomyces cerevisiae (baker’s yeast)
What are common characteristics of model genetic organisms?
- short generation time (faster reproduction)
- Production of numerous progeny (multiple sets of offspring over time)
- Can control and make genetic crosses
- Can measure results in a lab and controlled environment
- Lots of genetic variants
- Has been studied before and there is a wide knowledge on the organism
What is pangenesis?
the concept that each part of the body contains its genetic information. Gemmules carry the info from the parts of the body to the reproductive organs. This info is passed to the embryo during conception
What is Lamarckianism?
AKA: inheritance of acquired characteristics
Belief that if you do something during your lifetime, it would be passed to the offspring.
What is preformationism?
Belief that the egg or sperm has a tiny, fully formed human (a homunculus). It enlarged in the course of development. This is inherited from only one parent.
What is blending inheritance?
Traits of offspring are a blend/mixture of parental traits. NOT a blend of info at a molecular level.
In order, who contributed to the rise of genetics?
- Gregor Mendel
- Schleiden and Schwann
- Flemming
- Darwin
- Weismann
- Sutton
What did Gregor Mendel do?
• Discovered the basic principles of heredity
• laid the foundation for our modern understanding of heredity
• recognized as the father of genetics
What did Scleiden and Schwann discover?
Cell Theory:
1. All life composed of cells
2. Cells arise only preexisting cells
3. Cells are the fundamental unit of structure and function in living organisms
What did Flemming do?
- observed the division of chromosomes in 1879
- published description of mitosis.
What did Darwin discover?
- put forth the theory of evolution through national selection
- published his ideas in On the Origin of Species in 1859
What did Weismann discover?
THE GERM PLASM THEORY
- cells in reproductive organs carry a complete set of genetic information that is passed to the egg and sperm
- no more acquired characteristics
What did Walter Sutton discover? (1877-1916)
- genes are units of inheritance
- genes located on chromosomes
What did Thomas Hunt Morgan discover (1877-1916)?
FATHER OF FRUIT FLY GENETICS
- discovered the first mutant fruit fly in 1910
- used fruit flies to unravel transmission genetics
What did Fisher, Haldane, and Wright discover?
- They laid the foundation for population genetics by integrating Mendelian genetics and evolutionary theory.
What is the Cell Theory?
All life if composed of cells and cells arise only from cells
What is Mendelian inheritance?
the transmission of inherited characters from generation to generation through the transmission of genes
What do genes make up?
The genome
What are genes encoded in?
DNA
What are gene variants called?
Alleles
Where are genes located on?
chromosomes
What are histones?
Proteins found in eukaryotes that help regulate the accessibility of DNA to enzymes and other proteins that copy and read DNA.
- Enable DNA to fit into the nucleus
What are the key components of prokaryotes?
- no nucleus
- one circular DNA molecule
- not complexed with histones in bacteria
- no membrane-bounded organelles
What are key component of eukaryotic cells?
- have a nucleus
- have membrane-bounded organelles
What are the key components of viruses?
- not cellular, no cell structure
- neither prokaryotic or eukaryotic
- outer protein coat surrounding nucleic acid (DNA or RNA)
- can only reproduce within host cell
What are the steps of prokaryotic cell reproduction?
By BINARY FISSION
1. start at origin of replication
2. as the chromosome relocated, the origins segregate to opposite sides
3. Binary fission begins with a DNA copy in each
4. Cell divides. New cell wall form between the two chromosomes. Producing two cells, containing an identical copy of the chromo
What are diploid cells?
They carry two sets of genetic info on pairs of homologous chromosomes (2n)
What are haploid cells?
(n) They carry one set of genetic info. Could be reproductive or somatic cells.
What is a centromere?
The attachment point that contain the kinetochore for spindle microtubules to attach to
What are telomeres?
They are the ends of linear chromosomes. They protect and stabilize the chromosome ends.
What is the origin of replication?
Where DNA synthesis begins.
What are sister chromatids?
Two IDENTICAL copies of a chromosome that are held together at the centromere. Each sister chromatid consists of a single molecule of DNA.
Where is a submetacentric centromere located?
A little above the middle
Where is a metacentric centromere located?
Right in the middle
Where is a telocentric centromere located?
On the telomeres