Codominance & Blood Types
What does codominance mean?
Both alleles are fully expressed in the phenotype.
What animal changes color depending on the season?
What does DNA stand for?
What does DNA stand for?
Which enzyme unzips the DNA strand?
DNA Helicase
What is the first step of DNA replication?
Helicase unzips the DNA strands.
What is an example of codominance in humans?
AB blood type — both A and B alleles are equally expressed.
Why does the Arctic fox turn white in winter?
Because the pigment genes turns off in cold weather.
Where is DNA found in a cell?
In the nucleus.
Which enzyme builds new DNA strands by adding nucleotides?
DNA polymerase
What does “semi-conservative” mean in DNA replication?
Each new DNA molecule has one old (original) strand and one new strand.
If one parent has type A blood and the other has type B, what blood type can the child have if both alleles are expressed?
Type AB blood
How can the environment affect a person’s IQ?
IQ can only reach its potential when supported by good nutrition, sleep, and learning activities.
What is the shape of a DNA molecule?
A double helix.
Which enzyme glues DNA fragments together on the lagging strand?
DNA ligase
Which enzyme is used last during DNA replication?
DNA Ligase
How is codominance different from incomplete dominance?
Codominance shows both traits equally (red + white = red & white), while incomplete dominance blends them (red + white = pink).
Name two environmental factors that influence gene activation.
Temperature and nutrition (others include sleep, learning, or pollution).
What bases pair together in DNA?
A pairs with T, and C pairs with G.
What is the difference between the leading and lagging strands?
The leading strand is built continuously, while the lagging strand is built in short fragments.
Why is DNA replication important for mitosis and meiosis?
Because cells need a full set of identical DNA before dividing.
True or False — Codominance means one allele hides the other.
False — both alleles show equally.
How does temperature affect gene activation in animals like the Arctic fox?
Warm temperatures activate the pigment gene, while cold temperatures turn it off, changing fur color.
Why must DNA be copied before a cell divides?
So that each new cell gets a full set of genetic instructions.
What are the three main enzymes in DNA replication?
Helicase, Polymerase, and Ligase
List all steps of DNA replication in order.
Unzip the DNA with Helicase
Add primers to start copying
DNA Polymerase adds new nucleotides
Ligase seals fragments on the lagging strand
Two identical DNA molecules are formed