1.1. Science of Genetics Flashcards
• History of Genetics • Approaches in Genetics • Model Organisms in Genetic Studies • Genetics in the Society
science of heredity and variation
genetics
passing of characteristic/hereditary properties from parents to offspring (one cell generation to next); most striking attribute of a living cell
heredity
differences in physical, chemical, or behavioral traits
variation
defines heredity and variation; provides information regarding the biological properties of the individual
genes
proposed by aristotle; bearers of hereditary traits
humors
theory: fertilized egg contains a complete miniature adult; how is this adult called?
theory of preformationism; homunculus
theory: living things originate from nonliving components; also known as abiogenesis theory
spontaneous generation theory
how was the abiogenesis theory abolished?
louis pasteur’s swan neck experiment wherein he showed that broth remained free of microorganisms when protected from airborne particles
theory: an organism develops from the fertilized egg by a succession of developmental events that eventually transform the egg into an adult; e.g., butterfly, frogs
theory of epigenesis
proponent of theory of epigenesis
william harvey
proponents of cell theory
matthias schleiden and theodor schwann
postulates of cell theory
- all organisms are composed of basic structural units (cells)
- cells are derived from preexisting cells
author of “the origin of species” wherein he described his ideas on evolution
charles darwin
ship used by charles darwin during his expedition
HMS beagle
charles darwin proposed that existing species arose by descent with modification from ancestral species. species undergo change from generations to generations as their offsprings inherit traits from their parents; these traits are not identical due to mutation, recombination, and other factors. these changes all lead to diversity in species. true or false?
true
theory proposed by charles darwin on the idea of survival of the fittest and the mechanisms of evolutionary change
theory of natural selection
another scientist who also proposed an idea similar to the theory of natural selection
alfred russel wallace
the theory of natural selection was widely accepted during darwin’s time. true of false?
false. most people lacked an understanding of the genetic basis of variation and inheritance
an augustinian monk who conducted a decade-long series of experiments using pea plants
gregor johann mendel
gregor mendel’s work that explained how traits were passed from generation to generation in pea plants and all other organisms, providing the foundation of genetics
1866 publiciation: experiments on plant hybridization
life of mendel: his prof in vienna
christian doppler; discovered doppler effect
life of mendel: how many years did mendel study pea plants (over 28k)
eight years
life of mendel: cause of death
nephritis (kidney disease)
mendel’s work was widely accepted during his time. true or false?
false. his work was just rediscovered by scientists (i.e., hugo de vries, carl correns, erich von tschermak-seysenegg) during 1900
theory: states that (1) inherited traits are controlled by genes residing on chromsomes, and that (2) chromosomes are faithfully transmitted through gametes, maintaining genetic continuity from gen to gen
chromosome theory of inheritance
proponents of chromosome theory of inheritance
walter sutton and theodor boveri
an observation made by walter sutton and theodor boveri that became the cornerstone of the chromosome theory of inehritance
chromosomes during meiosis follow the same behavior of genes during gamete formation
1933 nobel prize winner in physiology or medicine who worked on the role of chromosomes in heredity
thomas hunt morgan
conducted transformation experiments to understand how certain strains of the bacterium streptococcus pneumoniae caused disease
frederick griffith
strains of s. pneumoniaie used by griffith in his experiment
IIR, IIIS
griffith’s experiment:
(1) injecting mice with the S strain killed them
(2) injecting mice with the R strain did not harm them.
(3) heat-killing the S strain and injecting it into mice did not harm them
(4) mixing heat-killed S strain with live R strain and injecting this mixture into mice killed them.
what conclusion did he arrive into?
a “transforming principle” from the dead S strain had been taken up by the living R strain which transformed them into the virulent S strain
scientists who discovered the identity of the transforming principle
oswald avery
colin macleod
maclyn mccarty
oswald avery, colin mcleod, and maclyn mccarty’s experiment:
(1) heat-killed IIIS were used to see if they could transform non-virulent IIR cells into virulent ones
(1) the filtrate was treated with enzymes: DNAse, RNAse, and protease
(2) protease and RNAse treatment: when the heat-killed IIIS cells were treated with protease and RNA respectively and then mixed with IIR cells, transformation still occurred.
(2) DNase Treatment: when the heat-killed IIIS cells mixed with IIR cells were treated with DNase, no transformation occurred.
what conclusion did they arrive into?
dna is the transforming substance given that no transformation occurred when the dna from the s strain was broken down during the DNAse treatment
scientists who built on the earlier work of avery, mcleod, and mccarty; provided further evidence that dna, not protein, is the genetic material
alfred hershey and martha chase
hershey-chase experiment:
(1) DNA of the T2 bacteriophages was labeled with radioactive phosphorus-32 (^32P), since DNA contains phosphorus
(2) the protein coat was conversely labeled with radioactive sulfur-35 (^35S), since proteins contain sulfur
(3) the labeled bacteriophages were allowed to infect ecoli. during infection, the phages attach to the bacterial cell and inject their genetic material into it.
(4) after the injection, the mixture was agitated in a blender to separate the phage coats from the bacterial cells and was centrifuged to separate the heavier bacterial cells from the lighter phage coats
(5) radioactive DNA (^32P) was found in the bacterial pellet, indicating that DNA had entered the bacterial cells
(6) radioactive protein (^35S) was dound in the supernatant, indicating that the protein coats did not enter the bacterial cells
what conclusion did they arrive into?
dna is the genetic material that bacteriophages inject into bacteria to produce new viruses; dna is the carrier of genetic information
scientist who studied dna by xray crystallographic technique
maurice wilkins
who created photo 51?
rosalind franklin
approach in genetics that focuses on patterns or mode of inheritance of traits
transmission genetics
approach in genetics that focuses on chromosomes and their behavior during mitosis and meiosis
cytogenetics
approach in genetics that focuses on the analysis of the outcomes of crosses between different strains of organisms
classical genetics
approach in genetics that focuses on replication, expression, and mutation of genes at the molecular level, as well as dna sequencing and manipulation
molecular genetics
approach in genetics that defines how and why certain genetic variation is maintained in populations
population genetics
approach in genetics that focuses on the statistical relationship between genes and the traits they encode
quantitative genetics
first known human immortal cell line
HeLa cell line
how does genetics help in today’s society?
(1) serves as a tool for research to generate new knowledge
(2) helps advance the agriculture industry by improving strains, breeds, and varieties
(3) also advance medical science through gene therapy, understanding genetic diseases, and creating personalized medicines
social and legal issues re genetics
genetic applications, such as prenatal testing develop much faster than the social conventions, public policies, and regulatory laws; genetic discrimination, ownership of genes, genetic privacy, access to and safety of gene therapy
