Mendelian and molecular genetics Flashcards
what was the important question did Aristotle attempt to answer?
what is the essence of a chicken???
what is formal cause?
the structure, essence or pattern that gives a thing its identity
what was the blending theory of inheritance
the outdated theory that offspring inherit traits as a simple mix of their parents traits.
who was Gregor Mendel?
an Austrian monk credited as the father of genetics. he proposed a ‘particle’ theory of inheritance.
why are peas a good model for studying genetics?
controlled process
lots of offspring
short generation times
how was Mendel able to control genetic crosses in his experiment?
by studying strong traits.
what is true-breeding?
an organism continues to produce the same trait when cross fertilized with itself over many generations.
what is P-generation, f1-generation and F2-generation?
P-generation= parent generation
F1-generation= 1st generation
F2-generation= 1st generation crossed with itself.
what is Mendel’s Law of Segregation?
-an organism possesses two factors (alleles) for each trait.
-during gamete formation these factors segregate, such that a gamete possesses one factor for each trait.
-Fertilization restores the presence of two factors for each trait in the offspring
– Some factors are ‘dominant’ and mask the effect of ‘recessive’ factors
what does genotype mean
refers to the combination to the combination of factors (types of genes)
what does phenotype mean?
the type of trait as a result of genotype. ex. tall, short etc.
what does dominant and recessive refer to?
recessive and dominant alleles.
what is a dihybrid cross?
a genetic breeding experiment where two organisms with two different traits are crossed.
what is Mendel’s law of independent assortment
during gamete formation the factors of one trait segregate independently of factors for another trait.
how was Mendels work rediscovered?
William Bateson saw de Vries’s publication while completing a paper on ‘Problems of Heredity’ ; then searched out the copy of Mendel’s report in Cambridge University Library.
what did Thomas Morgan do?
used fruit flies in his experiments to demonstrate that genes are located on chromosomes, establishing the theory of heredity.
who coined the term ‘gene’ ?
Wilhelm Johannsen
what important functions must DNA perform?
DNA must copy itself with great fidelity and encode genetic information.
why were scientists interested in the structure of DNA?
understanding the structure of DNA allows for the understanding of how genetic information is copied, encoded and passed down through generations. this also allows for a deeper understanding of evolution.
what speculation did Schrodinger make about the structure of DNA?
“aperiodic crystal.” he stated that hereditary material is likely to be a molecule which unlike a crystal does not repeat itself, implying its nature allows for an infinite number of combinations with a small number of atoms.
how did Watson and Crick discover the structure of DNA
with the x-ray image made by Rosalind Franklin, known as photo 51.
what was Rosalind franklins contribution?
she was able to crystalize DNA and x-ray it to photograph DNA.
what is the structure of DNA
a double helix nucleotide with 4 nitrogenous bases, Thymine (T) Adenine(A) Cytosine (C) Guanine (G)
what are nucleotides?
phosphate sugars with hydrogen bonds connecting them to nitrogenous bases.
