Genetics Exam questions and
answers graded A+
What is genetics? - ANS✅✅The study of heredity and how inherited variation is encoded,
replicated, and expressed
What are the different areas of genetics? - ANS✅✅Transmission (Mendelian genetics, non-
Mendelian genetics, and heredity)
Molecular nature of genetic material (DNA structure, gene expression, and mutation/repair)
Population genetics (allelic frequencies and evolution)
How does genetics relate to the appearance of an individual? To the behavior of an organism? -
ANS✅✅Genetics encodes for the phenotype (with some environmental variation). One's
phenotype is their expressed traits (ex. behavior, appearance, etc.)
What are model organisms? What makes them useful? - ANS✅✅Model organisms are organisms
used in place of human subjects that have biological processes similar in some way to humans, so
the things we learn from them can be applicable or parallel to human processes, especially given
that humans are often not easily studied in a genetic capacity due to ethical or other reasons.
A good model organism is **small, has a short generation time, and produces a lot of offspring.**
Genetic Model Organisms Examples - ANS✅✅E. coli (prokaryote): Useful in the study of basic
genetic processes
Yeast (eukaryote): Useful in the study of basic genetic processes as a eukaryote
Arabidopsis (plant): One of the first plants to have their genome fully sequenced
C. elegans (nematode, protist): Useful in the study of cell differentiation and development and cell
potency (e.g. totipotency, pluripotency)
D. melanogaster (fruit fly): Transmission
Zebra Fish: Vertebrate model; useful in the study of melanin genes
Mice: Mammalian model
Why is genetics important to humans? - ANS✅✅Genes contribute to phenotype
Diseases
Breeding programs
, Genetic testing
Conservation
Agriculture
Medicine
Climate
Evolution
Manipulation of the genome
Meischer - ANS✅✅Nucleic acid discovered; isolated nuclei from white blood cells in pus.
Contained in acidic (negatively charged) material high in phosphorus - nuclein or nucleic acid
Levene - ANS✅✅Nucleotides;
Nucleic acid is made up of repeating units of 4, chemically similar components
Each component composed of a sugar, a phosphate and one of 4 bases
Called a nucleotide
The tetra-nucleotide
Single-stranded - box shape
It was thought that there was no variability of A, G, C, or T - it was thought that they just repeated
and DNA's purpose was not understood
Chargaff - ANS✅✅Chargaff's principle (A = T and G = C)
A+T does not equal G+C
A+G = T+C
Purines (A, G) = pyrimidines (C, T, U)
Order of nucleotides was variable, but it followed rules
Griffith - ANS✅✅Streptococcus bacterium (1928)
Transforming principle
Heat stable
Avery, McCarty, MacLeod - ANS✅✅Strong evidence that DNA is the transforming principle
Used Griffith's model system
answers graded A+
What is genetics? - ANS✅✅The study of heredity and how inherited variation is encoded,
replicated, and expressed
What are the different areas of genetics? - ANS✅✅Transmission (Mendelian genetics, non-
Mendelian genetics, and heredity)
Molecular nature of genetic material (DNA structure, gene expression, and mutation/repair)
Population genetics (allelic frequencies and evolution)
How does genetics relate to the appearance of an individual? To the behavior of an organism? -
ANS✅✅Genetics encodes for the phenotype (with some environmental variation). One's
phenotype is their expressed traits (ex. behavior, appearance, etc.)
What are model organisms? What makes them useful? - ANS✅✅Model organisms are organisms
used in place of human subjects that have biological processes similar in some way to humans, so
the things we learn from them can be applicable or parallel to human processes, especially given
that humans are often not easily studied in a genetic capacity due to ethical or other reasons.
A good model organism is **small, has a short generation time, and produces a lot of offspring.**
Genetic Model Organisms Examples - ANS✅✅E. coli (prokaryote): Useful in the study of basic
genetic processes
Yeast (eukaryote): Useful in the study of basic genetic processes as a eukaryote
Arabidopsis (plant): One of the first plants to have their genome fully sequenced
C. elegans (nematode, protist): Useful in the study of cell differentiation and development and cell
potency (e.g. totipotency, pluripotency)
D. melanogaster (fruit fly): Transmission
Zebra Fish: Vertebrate model; useful in the study of melanin genes
Mice: Mammalian model
Why is genetics important to humans? - ANS✅✅Genes contribute to phenotype
Diseases
Breeding programs
, Genetic testing
Conservation
Agriculture
Medicine
Climate
Evolution
Manipulation of the genome
Meischer - ANS✅✅Nucleic acid discovered; isolated nuclei from white blood cells in pus.
Contained in acidic (negatively charged) material high in phosphorus - nuclein or nucleic acid
Levene - ANS✅✅Nucleotides;
Nucleic acid is made up of repeating units of 4, chemically similar components
Each component composed of a sugar, a phosphate and one of 4 bases
Called a nucleotide
The tetra-nucleotide
Single-stranded - box shape
It was thought that there was no variability of A, G, C, or T - it was thought that they just repeated
and DNA's purpose was not understood
Chargaff - ANS✅✅Chargaff's principle (A = T and G = C)
A+T does not equal G+C
A+G = T+C
Purines (A, G) = pyrimidines (C, T, U)
Order of nucleotides was variable, but it followed rules
Griffith - ANS✅✅Streptococcus bacterium (1928)
Transforming principle
Heat stable
Avery, McCarty, MacLeod - ANS✅✅Strong evidence that DNA is the transforming principle
Used Griffith's model system
