Cornell Notes 21 Flashcards
(14 cards)
Define Inheritance
the process by which an offspring receives genes from its parents
How are genes found in sexual reproduction?
genes are always in pairs (one from the male parent and one from the female parent).
Define Allele
Allele= is a different form of the same gene
Define Dominant Allele
Dominant Allele= An allele whose trait always shows up in the organism when the allele is present.
If an offspring inherits a dominant allele from either parent, that trait will always show the offspring, but if the offspring inherits recessive alleles from each parent, a recessive trait will show
Define Recessive Allele
Recessive Allele= An allele that is hidden when the dominant allele is present.
You need two copies in order to show the recessive trait
Explain incomplete dominance and give an example
Occurs when an allele is only partially dominant.
Results in a mixing of the traits.
Ex: A white flower and a red flower produce a pink flower.
Explain codominance and give an example
Happens when two alleles are different, but equally dominant.
Both traits are expressed at the same time.
Ex: When a white cow mates with a black cow and the offspring have spots of both black and white.
Explain polygenic inheritance and give an example
When a single trait is controlled by more than one gene.
Very common in many human traits.
Ex: human height
What kind of traits are things you learn throughout your life
To ride a bike, or unicycle, how to solve very complicated math problems
Anything you learn in life that you were not born with
Called AQUIRED TRAITS
Describe acquired traits
Dependent on your environment
(You were born with the ability to learn how to speak, but your family and culture ultimately are what decided which languages you would learn.)
Why do we need both inherited and acquired
Organisms need both inherited traits and acquired traits in order to survive in most environments.
Define environmental factors (list some common factors)
Environmental Factors= Anything in the environment that can affect gene expression.
Common examples: tobacco smoke and UV radiation
Damaged genes do NOT get passed onto the next generation unless they are in the egg or sperm cells.
Define gene expression
Gene expression= determines how traits will appear.
Can damaged genes get passed onto the next generation
no
