biology: introduction to genetics Flashcards
WHAT IS GENETICS?
Understanding how characteristics are transmitted from parents to offspring
Began with Gregor Mendel
-1800s monk
- Researched pea plant heredity using observations and statistics
– Discoveries made apply to all organisms
what is heredity?
Passing of traits from parents to offspring
what did mendel do?
Studied seven traits of peas
trait
genetically determined variant of characteristic
how did mendel study his plants?
pollination experiments
pollination
Pollen from anther () transferred to ovary ()
self-pollination
Pollen and ovary from same plant
cross-fertilization
Pollen and ovary from different plants
true-breeding plants
All self-fertilized offspring have same trait as parent
what were Mendel’s conclusions?
- Pair of alleles controls each trait
- Law of Segregation
- Law of Independent Assortment
allele
different forms of a gene
gene
segment on DNA on chromosome that controls trait
dominant allele
hides the recessive trait
recessive allele
no observable effect on organism if dominant allele is present
law of segregation
Paired alleles segregate during meiosis
• Gametes receive one allele from each pair
law of independent assortment
- Alleles sort independently during meiosis
* Genes for one trait do not influence inheritance of genes for another trait
Molecular genetics
Study of structure/function of genes & chromosomes