Chapter 1 Flashcards
What are genes?
Sequences of DNA that encode RNA
Genes are the fundamental unit of heredity.
What is the genetic similarity between two people?
Approximately 99.9%
This statistic highlights the close genetic relationship among humans.
What is the structure of a chromosome?
A single molecule of DNA wrapped in a chromosome
Each chromosome contains numerous genes.
Define dominance in genetics.
One dominant allele can hide the phenotype of a recessive allele
This is a key concept in Mendelian genetics.
What is the central dogma of molecular biology?
DNA to RNA to protein
This describes the flow of genetic information.
What is heredity?
The transmission of characteristics from parent to offspring by means of genes
This process is fundamental to genetics.
What is a gene?
A sequence of DNA that controls and codes for the expression of an RNA
Many of these RNAs code for a polypeptide.
List the key historical figures in molecular biology.
- Darwin
- Mendel
- Sutton and Boveri
- Griffith
- Beadle-Tatum
- Avery, MacLeod, and McCarty
- Hershey-Chase
- Franklin and Wilkins
- Watson and Crick
These figures made significant contributions to the field.
True or False: Evolution occurs without heritable variation.
False
Heritable variation is essential for natural selection and evolution.
What did Griffith’s experiment demonstrate?
The transforming principle, where DNA is the genetic material in bacteria
This experiment laid groundwork for understanding DNA’s role.
What does the one gene-one enzyme hypothesis state?
Each gene encodes for a specific enzyme
This was later modified to the one gene-one polypeptide hypothesis.
What is the chromosome theory of inheritance?
Inheritance patterns can be explained by genes located on chromosomes
This theory integrates Mendel’s laws with chromosomal behavior.
Fill in the blank: The process by which a bacterium picks up exogenous DNA is called _______.
Transformation
This process is crucial for genetic exchange in bacteria.
What is the significance of Rosalind Franklin’s work?
Her X-ray crystallography data contributed to the discovery of DNA’s double helix structure
Franklin’s contributions were initially underappreciated.
What are the six important themes of scientific discovery in molecular biology?
- The study of mutations is a driving force
- Major breakthroughs follow technological advances
- Progress may result from competition and collaboration
- All research has developed within the framework of evolution
- Significant discoveries may be rediscovered later
- The biochemical basis of gene expression and its regulation
These themes guide research and understanding in molecular biology.
What is the role of mutations in genetics?
Mutations can cause permanent changes and are a driving force in genetics
They contribute to variation and evolution.
What is molecular biology?
The study of biological phenomena at the molecular level. (molecular structure of DNA, molecular structure of the information DNA encodes: RNA and Protein, Biochemical basis of gene expression and its regulation)
What is the year when Darwin concluded that evolution occurs?
1859
What are the three key components necessary for evolution to occur according to Darwin?
Variation, differential reproduction, heredity
Fill in the blank: Evolution occurs when _______ leads to differential success in reproduction.
heritable variation
What is implied by Darwin’s theory of evolution by natural selection regarding all organisms?
All organisms are related by common ancestry
True or False: Differential reproduction is one of the factors that leads to evolution.
True
What does natural selection require for evolution to occur?
Variation, differential reproduction, heredity
What is the chromosome theory of inheritance?
A unifying theory stating that inheritance patterns can be explained by assuming the genes are located in specific sites on chromosomes.
How does meiosis relate to Mendel’s Laws?
Meiosis explains Mendel’s Laws of Segregation and Independent Assortment.
What was the key finding of Griffith’s Experiment in 1928?
The transforming principle
Who conducted the experiment that identified DNA as the transforming molecule in 1944?
Avery, MacCleod, and McCarty
What theme is highlighted by the combination of in vivo and in vitro experiments?
Significant advances in understanding genetic material
What is the role of DNA in bacteria?
DNA is the genetic material in bacteria
Define transformation in the context of bacteria.
Process by which a bacterium picks up exogenous DNA
What is the main focus of the Beadle-Tatum Experiment conducted in 1941?
Biochemical pathway analysis
This experiment contributed to the understanding of gene function and its products.
What hypothesis is associated with the Beadle-Tatum Experiment?
One gene—one enzyme hypothesis
This hypothesis suggests that each gene encodes a specific enzyme.
How was the one gene—one enzyme hypothesis modified?
One gene—one polypeptide hypothesis
This modification reflects the understanding that genes can encode multiple polypeptides through alternative splicing.
What theme is highlighted by the study of mutations in genetics?
Driving force in genetics and modern molecular biology
Mutations provide insights into gene function and inheritance.
What significant finding did the Hershey-Chase Experiment in 1952 reveal?
DNA is the genetic material of bacteriophage T2
This experiment demonstrated that DNA, not protein, carries genetic information.
What theme is associated with major breakthroughs in genetics?
Major breakthrough follows technological advances
Advances in technology, such as the use of radioactive isotopes, facilitated significant discoveries.
What did Watson and Crick accomplish in 1953?
Elucidation of DNA structure
Their model of DNA’s double helix structure has been fundamental in genetics.
Did Watson and Crick conduct experiments to determine DNA structure?
No, only observations/interpretation of other scientists’ data
Their work was based on existing data, particularly from Rosalind Franklin’s X-ray diffraction images.
What is the structure of DNA?
Double helix
DNA is a double helix consisting of two polynucleotide chains that run antiparallel.
What does the Central Dogma of Molecular Biology state about DNA?
DNA is the hereditary material
Each chromosome is a single molecule of DNA, and genes are sequences of DNA.
True or False: DNA consists of three polynucleotide chains.
False
DNA consists of two polynucleotide chains.
Fill in the blank: The structure of DNA was determined to be a _______.
double helix
Who conducted X-ray crystallography of DNA?
Rosalind Franklin
This was done in Maurice Wilkins’s laboratory.
What may result from competition, collaboration, and the tenacity and creativity of individual investigators?
Progress in science
What are the six important themes of scientific discovery?
- Some great discoveries are not appreciated or
communicated to a wide audience until years after the discoverers are dead and their discoveries are “rediscovered.” - A combined approach of in vivo and in vitro studies has led to significant advances.
- The study of mutations is a driving force in genetics and in modern molecular biology.
- Major breakthroughs often follow technological
advances. - Progress in science may result from competition, collaboration, and the tenacity and creativity of individual investigators.
- All research in biology during the last 150+ years has developed within the framework of evolution.
