Mendelian inheritance Flashcards
What is heredity?
How parents pass characteristics to offspring
What is genetics?
The science of heredity
Who was Gregor Mendel?
Gregor Mendel was a monk that uncovered heredity and was named the father of genetics
what did gergor mendle use in his experiments
pea plants
What’ was the blending theory?
A theory that offspring have a blend of characteristic of their parents
Why did Gregor mendel use pea plants?
The pea plants were fast growing, easy to grow, and had different variations
- seeds, pods, size, color, position, stem length, round or wrinkled
What is pollination? When does it occur?
The fertilizing step in the sexual reproduction of plants
- occurs when pollen is transferred from the anther to the stigma
What is pollen? Where is it produced
Pollen is the male gamete of a plant and is produced by the male flower part the anther
What is the stigma? Where is it produced
stigma is the female gamete of the plant
- produced in the carpel
What is self- pollination?
Pollen grains from the anther is transferred to the stigma on the same plant
What is cross pollination? what doe suit result in?
Pollen grains from another anther on a different plant is transferd to the stigma of another plant
- results in hybrid offspring
What is mendle’s first set of experiments?
Mendel started with the flower color and experimented with 1 characteristic at a time
What were the steps of mendel’s first set of experiments?
- cross pollinated (fully breed) purple and white flowers (p generation)
- f1 generation= were all purple flowers (heterozygous Pp)
- f2 generation= some had white flowers as the f1 generation was allowed to self pollinate
what did Mendel conclude in his first set of experiments?
The 3:1 ratio 3 were purple and 1 was white
- 1 value of the characteristic disappeared in the f1 gen but reappeared in the f2 generation as a white flower
- 75% were purple and 25% were white
What is the p generation?
The fully breed purple and white flowers of mendel’s test
What is the f1 generation
The offspring of the p generation
What is the f2 generation?
The offspring of the f1 generation that were self polllinated
What is the law of segregation as?
States that there are 2 factors controlling a given characteristic one of which dominatates the other
- dominant and ressive genes
What is true breeding?
Parents that only produce white or purple flowers
- p gen were an example of this
What is a geneotype?
The genetic make up of an person
Ex: Pp, or Gg
Alleles that you recive from your parents
What is a phenotype?
The physical apperance
- ex: yellow or green tall or short
Dominant vs resscive genes
dominant genes are expressed
Resscive genes are not expressed
What is homozygous
2 of the same alleles
Ex: rr or pp
A trait can be fully either or
What is heterozygous
organisms with different alleles
Ex: Pp or Yy
How many geneotypes are there
3
Homozygous dominant PP
Homozygous resscive pp
Heterozygous Pp
What results in PP and Pp
Purple flowers because the dominant allele is expressed
What was mendel’s 2nd set ofd experiments?
-questions wether different characteristics are inherited together
-investigated 2 charctersistics at a time
What did mendel’s 2nd set of experiments result in?
A dyhibrid cross
- led to the law of independent assortment
what is a dyhibrid cross?
A cross between 2 f1 offspring that have different characteristics
What is the law of independent assortment?
Factors controlling different characteristics are inherited separately
What is a locus?
Position of a gene on a chromosome
What are alleles?
Different versions of a gene
What happens when an organism has different alleles
allows for the different variation in charcteristics of organism
How many copies of genes do organisms have
in sexual reproduction organisms have 2 copies of the same gene because they ressive 1 from each parent
What happens in meiosis that affects the alleles
in meiosis homolgous chromosomes separated and go to different gamers
- the 2 Allie’s for each gene also seperate and go to different gametes
- the different chromosomes assort independtly and the alleles also assort indecently
- a zygote inherites 2 Allen’s for each gene/ 1 allele form each parent
