11.1 Study Guide Flashcards
What are traits?
Distinguishing characteristics that are inherited.
What is Genetics the study of?
biological inheritance patterns and variations
What did Gregor Mendel show about traits?
that traits are inherited as discrete units
What did Mendel do with Pea Plants ?
Controlled fertilization by removing the male part of the pea plant (stamens) and fertilized the female part (pistil) with pollen from a different pea plant.
Observed traits (e.g., flower color, seed shape, pod shape, flower position, stem length) in each generation looking for patterns.
What are true-breeding plants?
organisms that consistently produce offspring with the same phenotype (observable traits) as the parents
What does it mean for alleles to be inherited as discrete units?
Instead of traits being a blend of parental characteristics, they are passed on as separate, indivisible units. For example, if one parent has red hair and the other has brown hair, their offspring might inherit either red hair or brown hair, but not a blend of both.
Mendel start with true breeding plants in the first generation which was called the “P” generation. What does the “P” stand for?
Parental Generation
What is the offspring of the P generation called?
F1 - First Filial Generation
What is the offspring of the F1 generation called?
F2 - Second Filial Generation
What pattern is seen in the F1 generation in Mendel’s experiments?
The F1 generation consistently exhibited the dominant trait observed in one of the parental plants.
What pattern is seen in the F2 generation in Mendel’s experiments?
A 3:1 ratio of dominant to recessive traits is typically observed.
This means that for every three offspring displaying the dominant trait, there is typically one offspring displaying the recessive trait.
What two major findings came from Mendel’s experiments?
- Traits are inherited independently are discrete units (alleles)
-Differences in DNA Sequence = Potential Difference in Protein - There are dominant and recessive alleles that results in dominant and recessive traits
Define allele.
Different versions of the same gene at the same location on homologous chromosomes.
Define genotype.
Complete set of genetic material for an organism.
Define homozygous alleles.
Having two identical alleles of a particular gene or genes.
Define heterozygous alleles.
Having two different alleles/ versions of the same gene or genes.
Define phenotype.
The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
What are the properties of a recessive allele?
-Often makes a malfunctioning protein, if only the malfunctioning protein is made it results in a recessive trait
Define recessive trait .
Heritable characteristics controlled by genes that are expressed in offspring only when inherited from both parents. Recessive traits can be passed on through generations, even if they are not expressed in every generation,
What are the properties of a dominant allele?
-Codes for a functional protein
-Only need one allele to have a working protein and show dominant trait
-Mask other alleles
Define dominant trait.
A characteristic that is more likely to be inherited and expressed when only one copy of the relevant gene is present.
P=Dominant Allele and p= Recessive Allele.
What letter combinations would represent 1) Homozygous Dominant
2)Homozygous Recessive and
3) Heterozygous?
- PP
- pp
- Pp and pP
Two organisms can have the same phenotype but different _______?
Provide and example.
Genotypes
P= Dominant Allele, p= Recessive Allele
PP and Pp have the same phenotype but different genotypes.
Review Questions on
Slide 22, 23 and 24
Slide 22 - Generation Traits and Naming; Determining Dominant and Recessive Traits
