Basic Principles of Heredity & Pedigree Analysis Flashcards
Why Study Genetics?
-play a critical role in understanding disease
-crossing certain crops with certain benefits to make new crops (grow tall, or make bigger fruit)
-use biotechnology industry for drug design development and production
(human protein insert into plasmid bacteria then stores insulin)
What are DNA Barcodes?
-provides new information
-use DNA as a fingerprint
-discover that two objects that are deemed to be different actually turn out to be the exact same thing or very similar
What are the fundamental concepts of genes, genotypes, & phenotypes?
-gene are on chromosome and include proteins two copies and sometimes 2 variations of alleles
-come in multiple forms called alleles
-genotype confers phenotype (homo or heterozygous)
-genetic info is transferred from DNA to RNA (transcription) and from RNA to a protein (translation)
What is the locus?
the specific place on a chromosome occupied by an allele
(we know where the gene is)
What is a heterozygote?
an individual organism possessing two different alleles at a locus
What is a Homozygote?
an individual organism possessing two of the same alleles at a locus
What is a phenotype or trait?
the appearance or manifestation of a character
Who discovered the basic principles of Heredity?
Gregor Johann Mendel
What is a monohybrid cross?
-a cross of two true breeding parents (only one type of allele)
-they can only make what they are (same progeny)
What occurred in the P generation?
-Mendel crossed a plant homozygous for round seeds (RR) with a plant homozygous for wrinkled seeds (rr)
-the 2 alleles in each plant separated when gametes were formed one allele went into each gamete
What occurred in the F1 generation?
Gametes fused and produced heterozygous plants with round seeds discovered to be the dominant (Rr)
-Mendel self-fertilized the F1 to produce F2
-The law of segregation occurred at the R and r alleles separated (self-fertilization)
What occurred in the F2 generation?
-3/4 round (RR, Rr, rR) and 1/4 wrinkled (rr) *reappeared
-appeared in a 3:1 ratio of round to wrinkled
-1/2 time you can transmit your recessive allele
-Mendel self-fertilized the F2
-two ways to heterozygous (Rr & rR)
What occurs in Mendel’s dihybrid crosses?
-introduced the law of independent assortment
-P gen: start with true breeding parents one yellow round and one green wrinkled
-F1 gen: yellow round traits appear to be dominant
-F2 gen: self fertilize and recessive gene reappears
-yellow round (315), green round (108), yellow wrinkled (101), green wrinkled (32)
approx 9:3:3:1 ratio
What always stems from dihybrid crosses?
9 individuals with both dominant traits
3 individuals with one dominant trait and one recessive trait
3 individuals with the other dominant trait and the other recessive trait
1 individual with both recessive traits
