Intro to genetics Flashcards
(17 cards)
What is the Law of Segregation?
Organisms have 2 copies of each gene that segregate randomly into sperm or eggs
Copies remain unaltered and are inherited from each parent.
What does the Law of Independent Assortment state?
Different traits are inherited independently of each other
This means the inheritance of one trait does not affect the inheritance of another.
What is the Law of Dominance?
One allele may be dominant while the other is recessive
The dominant allele is expressed, while the recessive allele is masked.
Define particulate inheritance.
Traits are passed through discrete units (genes), not blended
This concept was introduced by Mendel.
What are alleles?
Different versions of the same gene
Alleles can be dominant or recessive.
What does homozygous mean?
Identical alleles
An organism with two identical alleles for a trait.
What does heterozygous mean?
Different alleles
An organism with two different alleles for a trait.
How did Mendel control parent information?
Used true-breeding strains
This allowed him to rigorously test hypotheses on inheritance.
What did Walter Sutton and Theodor Boveri discover in 1902?
Chromosomes are inherited from both parents and segregated during meiosis
This was a key breakthrough in understanding genetic inheritance.
What did Ronald Fisher contribute to genetics in 1911?
Explained complex traits via multiple additive genes
This laid the groundwork for quantitative genetics.
What was the outcome of Griffith’s Transformation Experiment?
Indicated a ‘transforming principle’ transferred virulence
Later determined to be DNA.
What does the phrase ‘Omne vivum ex ovo’ mean?
All life from eggs
This was proposed by William Harvey.
What is preformationism?
The theory that an embryo is a tiny fully-formed adult (‘homunculus’) that simply grows
This theory has been largely discredited.
What is epigenesis?
Adult forms develop from simpler forms with a developmental program
This is the currently accepted view of embryonic development.
What is the accepted view of life origins?
Life comes from pre-existing life
Life begins from eggs/embryos that contain instructions to become adults.
True or False: Blending inheritance explains trait persistence.
False
Mendelian genetics shows inheritance is particulate and explains trait persistence.
What was Darwin’s Pangenesis Hypothesis?
Body organs release ‘gemmules’ into gametes
This hypothesis was disproved by Galton’s Rabbit Experiment.
