Lecture 2 Flashcards
MENDEL’S INHERITANCE
GENETICS
Branch of biology that deals with heredity and variation of organisms; study of genes and inheritance.
Branch of biology that deals with heredity and variation of organisms; study of genes and inheritance.
GENETICS
foundation of forest tree breeding and improvement
GENETICS
GENETICS
foundation of forest tree breeding and improvement
FOREST GENETICS
study of heredity in forest trees
study of heredity in forest trees
FOREST GENETICS
the sub-discipline of genetics concerned with genetic variation and inheritance in forest trees
FOREST GENETICS
FOREST GENETICS
the sub-discipline of genetics concerned with genetic variation and inheritance in forest trees
provides the knowledge necessary to breed trees through traditional methods of selection and hybridization, and also through newer biotechnologies
FOREST GENETICS
FOREST GENETICS
provides the knowledge necessary to breed trees through traditional methods of selection and hybridization, and also through newer biotechnologies
PHENOTYPE
Interaction of environment and genotype
Interaction of environment and genotype
PHENOTYPE
TWO VIEWPOINTS OF HEREDITY
BLENDING
PARTICULATE
BLENDING
PARTICULATE
TWO VIEWPOINTS OF HEREDITY
Hypothesis: genetic materials from two parents blends together; offspring were essentially a “dilution” of the different parental characteristics
BLENDING
BLENDING
Hypothesis: genetic materials from two parents blends together; offspring were essentially a “dilution” of the different parental characteristics
Ex. Blue + Yellow = Green
BLENDING
BLENDING
Ex. Blue + Yellow = Green
PARTICULATE
Hypothesis: parents pass on discrete heritable units (now known as genes)
Hypothesis: parents pass on discrete heritable units (now known as genes)
PARTICULATE
GENES (CHARACTER)
functional units of DNA that code for specific traits
functional units of DNA that code for specific traits
GENES (CHARACTER)
Ex. Plant height; Fruit Color
GENES (CHARACTER)
GENES (CHARACTER)
Ex. Plant height; Fruit Color
ALLELE (TRAIT)
specific characteristics that vary from individual to individual as coded by the DNA
specific characteristics that vary from individual to individual as coded by the DNA
ALLELE (TRAIT)
Ex. Short/tall; Yellow/Green
ALLELE (TRAIT)
ALLELE (TRAIT)
Ex. Short/tall; Yellow/Green
GREGOR MENDEL
“Father of Genetics”
“Father of Genetics”
GREGOR MENDEL
In 1866 GREGOR MENDEL published
Experiments in Plant Hybridization, (Versuche über Pflanzen-Hybriden) in which he established his 3 Principles of Inheritance
Mendel looked at
seven traits or characteristics of pea plants:
TRUE-BRED (PURE BRED)
all offspring of same variety
TRUE-BRED (PURE BRED)
HYBRIDIZATION
crossing of 2 different true-breds
crossing of 2 different true-breds
HYBRIDIZATION
MONOHYBRID CROSS
a genetic cross involving a single pair of genes (one trait); parents differ by a single trait.
a genetic cross involving a single pair of genes (one trait);
parents differ by a single trait.
MONOHYBRID CROSS
P
Parental generation
Parental generation
P
F1
First filial generation; offspring from a genetic cross
First filial generation; offspring from a genetic cross
F1
F2
Second filial generation of a genetic cross
Second filial generation of a genetic cross
F2
DIHYBRID CROSSES
Matings that involve parents that differ in two genes (two independent traits)
Matings that involve parents that differ in two genes (two independent traits)
DIHYBRID CROSSES
LAW OF DOMINANCE
In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation.
In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation.
LAW OF DOMINANCE
Offspring that are hybrid for a trait will have only the dominant trait in the phenotype.
LAW OF DOMINANCE
LAW OF DOMINANCE
Offspring that are hybrid for a trait will have only the dominant trait in the phenotype.
One allele masked another, one allele was dominant over
the other in the F1 generation
LAW OF DOMINANCE
LAW OF DOMINANCE
One allele masked another, one allele was dominant over the other in the F1 generation
HOMOZYGOUS
having identical alleles (one from each parent) for a particular characteristic
having identical alleles (one from each parent) for a particular characteristic
HOMOZYGOUS
HETEROZYGOUS
having two different alleles for a particular characteristic
having two different alleles for a particular characteristic
HETEROZYGOUS
DOMINANCE
the allele of a gene that masks or suppresses the expression of an alternate allele
the allele of a gene that masks or suppresses the expression of an alternate allele
DOMINANCE
the allele of a gene that masks or suppresses the expression of an alternate allele
DOMINANCE
DOMINANCE
the allele of a gene that masks or suppresses the expression of an alternate allele
an allele that is masked by a dominant allele
RECESSIVE
RECESSIVE
an allele that is masked by a dominant allele
does not appear (not seen in the phenotype) in the heterozygous condition, only in homozygous.
RECESSIVE
RECESSIVE
does not appear (not seen in the phenotype) in the heterozygous condition, only in homozygous.
When gametes are formed, the pairs of hereditary factors (genes) become separated, so that each sex cell (egg/sperm) receives only one kind of gene.
LAW OF SEGREGATION
LAW OF SEGREGATION
When gametes are formed, the pairs of hereditary factors (genes) become separated, so that each sex cell (egg/sperm) receives only one kind of gene.
LAW OF INDEPENDENT ASSORTMENT
Alleles for different traits are distributed to sex cells (& offspring) independently of one another.
Alleles for different traits are distributed to sex cells (& offspring) independently of one another.
LAW OF INDEPENDENT ASSORTMENT
“Members of one gene pair segregate independently from other gene pairs during gamete formation”
LAW OF INDEPENDENT ASSORTMENT
LAW OF INDEPENDENT ASSORTMENT
“Members of one gene pair segregate independently from other gene pairs during gamete formation”
TEST CROSS
Cross with a homozygous recessive individual
TEST CROSS
BACKCROSS
Crossing of a hybrid with one of its parents, in order to achieve offspring with a genetic identity which is closer to that of the parent.
Crossing of a hybrid with one of its parents, in order to achieve offspring with a genetic identity which is closer to that of the parent.
BACKCROSS
INCOMPLETE DOMINANCE
individuals with heterozygous alleles exhibit a phenotype intermediate between those with homozygous alleles
individuals with heterozygous alleles exhibit a phenotype intermediate between those with homozygous alleles
INCOMPLETE DOMINANCE
COMPLETE DOMINANCE
offspring always looked like one of their two parents (Mendel’s experiment)
offspring always looked like one of their two parents (Mendel’s experiment)
COMPLETE DOMINANCE
