Unit 1 - Genetics Flashcards
Evolutionary Biology
The scientific study of the
evolutionary processes that produced the
diversity of life on Earth.
Ecology
The scientific study of the interactions
between organisms and the living and nonliving
components of their environment
Hypothesis
An explanation, based on
observations and assumptions, that leads to a
testable prediction.
Experiment
A scientific test, carried out under
controlled conditions.
Which laws govern Mendelian inheritance?
Probability
Evolutionary Synthesis
What is Mendel’s model of inheritance combined with
Darwin’s theory of natural selection called?
Inheritance
How traits are passed from
parents to offspring
What is the blending model?
The idea that genetic material from two parents blends together. Leads to the loss of variation.
What is the particulate model of inheritance?
The idea that parents pass
on discrete heritable
units.
What is special about true breeding plants?
When self-pollinated, they produce offspring that all have identical traits.
What are genes?
Discrete heritable units on chromosomes.
Why did Mendel use peas?
Mating could be controlled, plants could be allowed to self-pollinate or could be cross-pollinated, short generation time, large numbers of offspring, many varieties
What are alleles?
Alternative versions of
genes that account for variation
in inherited characters.
What is a genotype?
Genetic makeup of an organism.
What is a phenotype?
Physical appearance of an organism.
What is being diploid?
Having two copies of each chromosome.
What is the difference between heterozygote and homozygote?
Heterozygote - Organism has two alleles that are the different.
Homozygote - Organism has two alleles that are the same.
What is a gamete?
A haploid reproductive cell, such as an egg or sperm, that is formed by meiosis.
What is a monohybrid?
It means that the offspring is heterozygous for one character.
What was Mendel’s law of independent assortment?
Each pair of alleles segregates independently of any other pair of alleles during gamete formation.
A pea plant is heterozygous at the independent loci for flower color (Pp) and seed color (Yy). How many unique genotypes can it produce?
Four: pY, Py, py, PY
What is a monohybrid cross?
A cross between two organisms that are heterozygous for the character.
What is a dihybrid cross?
A cross between two organisms that are each heterozygous for both of the characters being followed.
What is a multi-character cross?
Two or more independent monohybrid crosses occurring simultaneously.
When does complete dominance occur?
When phenotypes of the heterozygote and dominant homozygote are identical.
When does incomplete dominance occur?
The phenotype of F1 hybrids is
somewhere between the phenotypes of the two parental varieties.
When does co-dominance occur?
Two alleles affect the phenotype in separate, distinguishable ways.
What is the Tay-Sachs disease?
It is caused by a single gene that has two alleles.
What is the dominance relationship between the three main alleles for blood type?
IA and IB are codominant and are dominant to i
What is a pleiotropy?
Genes that have multiple phenotypic effects.
What happens in epistasis?
One gene affects the phenotype of another due to interaction of their gene products.
What happens in polygenic inheritance?
Multiple genes independently affect a single trait.
What is an example of epistasis?
In Labradors one gene determines the pigment color, while the other determines whether the pigment will be deposited in the hair.
What is a qualitative character?
A character that has a few discrete types.
What is a quantitative character?
A character that varies in the population along a continuum.
What is an example of polygenic inheritance?
Height
What is phenotypic plasticity?
The ability of an organism to change in response to stimuli or inputs from the environment.
What is a multifactorial trait?
A trait that depends on multiple genes combined with environmental influences.
What is an example of a multifactorial trait?
Human skin color
What is a carrier?
An individual who is heterozygous at a given genetic locus for a recessively inherited disorder.
What is a pedigree?
A family tree that describes the inheritance of a trait across generations.
What is association study?
It is data to correlate genotypes and phenotypes across many individuals.
What are non-coding elements?
Sequences and regions in
the genome that do not code for protein or RNA.
What is a mutation?
It is a change in DNA sequence relative to some standard or previously existing sequence. Mutations are always random.
What is a mutant?
It is an individual whose genome contains a mutation at some location of interest.
What is phenotypic variation?
It is variation in phenotypes among a group of organisms.
What is genetic variation?
It is variation in mutations and/or alleles among members of a group of
organisms.
What are somatic mutations?
They are mutations that occur in the
body tissues of an organism. They’re not transmitted to the next generation.
What are germline mutations?
They are mutations that occur in the
gametes and are transmitted to offspring.
What is a mutagen?
It is a substance or environmental factor that increases the rate at which mutations occur (causes mutations).
What are error correction mechanisms?
They are cellular/molecular mechanisms that correct most
errors in DNA replication/meiosis.
What is non-disjunctions?
When chromosomes fail to
correctly separate during meiosis.
What are deleterious mutations?
Mutations that cause a decrease in an organisms fitness.
What are beneficial mutations?
Mutations that cause an increase in an organisms fitness.
What are neutral mutations?
Mutations that cause no change in an organisms fitness.
