Exam #4 - Genetics Flashcards
Is blending a correct model of inheritance?
No
Why did Gregor Mendel study pea plants?
1) Peas are eukaryotes
2) Cheap and easy to handle
3) Within a short amount of time, you can generate the next generation. Within a year or less
A character = ?
A characteristic
Flower color is a ________?
The plant height is a ________?
The pea color is a _________?
The pod shape is a __________?
Characteristic. These are all TRAITS
Variety is a TYPE of _________.
character
Red flowers….white flowers…tall height…small height…yellow peas…green peas…these are ________.
varieties. (Varieties are more SPECIFIC)
- **Trait: Flower Color
- **Variety: Red Flower (MORE SPECIFIC = VARIETY)
T/F: A pea plant can fertilize itself
True
In nature: self pollinate
Mendel: ____ _______
cross pollinate
Start with a parent that produces offspring just like itself…this is called _____ _______.
true breeding
Start with true breeding, but take two _______ true breeding varieties and _____ them. See what you get!
different, cross
This was Mendel’s experiment:
Take a true breeding parent of one ______, and cross it with a true breeding individual of another ______. Same characteristic, but two different _______. And that will produce an offspring.
variety
Since this offspring is a parent of two varieties, it is known as a ______.
hybrid.
A hybrid generate by cross pollination
The hybrid is then allowed to ____ ________.
This last group of offspring is analyzed to see what conclusion we can draw.
self pollinate
The original generation is called _.
The hybrids are called __.
The final set of offspring is called __.
P
F1
F2
Mendel’s experiment #1:
Crossed a true breeding individual with ______ seeds with a true breeding individual with _______ seeds.
round, wrinkled
What are the offspring? (F1)
All round
What were the results of the final offspring? (F2)
Round, wrinkled. 3:1 ratio
Wrinkled came back…
What conclusions did he draw from experiment #1?
1) His observations contradicted the blending model
2) Characters/traits are produced by ‘heritable factors’ that are DISCRETE
**Today we know that ‘heritable factors’ = genes
Experiment #1 conclusions:
1) Characters/traits are produced by ‘heritable factors’ that are DISCRETE
2) An organism has ___ genes for each trait.
- ___ from each parent
Today we know:
We inherit a pair of ________ _________
-They have the _____ GENES!
two
one
homologous chromosomes
SAME
Why different phenotypes for a trait?
A gene has different “versions” or alleles (round, wrinkled)
Experiment #1 conclusions:
1) Characters/traits are produced by ‘heritable factors’ that are DISCRETE
2) An organism has TWO genes for each trait.
3) Genes have alternate versions called _______.
Today we know:
A gene can vary in its ________ ________.
alleles
nucleotide sequence
Based on mender’s experiment…
Round seed phenotype: _________
Wrinkled seed phenotype: _________
DOMINANT
Recessive
Experiment #1 conclusions:
1) Characters/traits are produced by ‘heritable factors’ that are DISCRETE
2) An organism has TWO genes for each trait.
3) Genes have alternate versions called ALLELES
4) When different alleles are TOGETHER:
- Dominant allele: affects ________.
- Recessive allele: DOES NOT affect ________.
appearance
Experiment #1 conclusions:
1) Characters/traits are produced by ‘heritable factors’ that are DISCRETE
2) An organism has TWO genes for each trait.
3) Genes have alternate versions called ALLELES
4) Dominant allele: affects appearance
5) Alleles separate during gamete production.
- This is called ____ __ _________.
Today we know:
_______ __________ separate during meiosis I
Law of segregation
homologous chromosomes
Particulate Model of Inheritance:
‘Genetic material’ is composed of UNITS which are passed on to offspring, and which retain their ________.
IDENTITIES
Why 3:1 in F2?
USE A PUNNET SQUARE!
Punnet Square: predicts the result of a cross by accounting for _______ fertilization.
random
______ is the process of change in the genetic code.
mutation
Every allele today came about by _______.
mutations
_______ is the physical appearance of an organism.
phenotype
The genes that you have, or genetic makeup, is called _______.
genotype
Your _______ is what gives you your ________.
genotype, phenotype
The ________ of the parents are purple flower and white flowered plants
phenotypes
The ________ is two dominant alleles, two purple alleles, two recessive alleles.
genotype
If you have two of the same allele, you are said to be _________.
homozygous
If you have two different alleles, you are said to be ________.
heterozygous
A true breeding individual is _________.
homozygous
The F1 is _________.
heterozygous