DNA and Chromosomes
Where is DNA found inside MOST cells?
The nucleus
What is a gene?
A section of DNA that contains instructions for a trait
What is a dominant allele?
An allele that shows up when at least one copy is present
Which term refers to what you can see: genotype or phenotype?
Phenotype
What is a Punnett square used for?
To predict the possible genetic outcomes of offspring
This video game system, released in 2006, revolutionized gaming by allowing players to move as if they were actually bowling or playing golf.
The Nintendo Wii
What does DNA stand for?
Deoxyribonucleic Acid
What is a trait?
A characteristic of an organism (such as eye color or height)
How many recessive alleles are needed for a recessive trait to appear?
Two
Why is genotype considered “hidden”?
Because you cannot see it just by looking at an organism
Where do the parents’ alleles go when setting up a Punnett square?
One parent’s alleles go across the top, the other goes down the side
I am a chess piece that can move in an L-shape.
A Knight
What are the four bases in DNA?
Bonus: Saying their full names.
A, T, C, G (adenine, thymine, cytosine, guanine)
Where do you get your genes from?
Half from your mother and half from your father
What does it mean if a recessive trait is “hidden”?
It is present but not expressed because a dominant allele is masking it
If an organism has genotype bb, what must its phenotype be?
The recessive trait
If you cross Bb × Bb, what is the probability of getting bb?
25% (1 out of 4)
In the massive Roblox hit Blox Fruits, what is the name of the special items that give players unique combat abilities?
Devil Fruits (or Blox Fruits)
A scientist finds two cells in the same person. One has DNA and one does not.
Which type of cell is most likely missing DNA, and why?
A red blood cell, because it does not have a nucleus
A person has a gene for a trait, but it does not show up in their appearance.
Give one possible explanation.
The gene may be turned off, or it could be recessive and masked by a dominant allele
A person has a dominant trait. What are the possible genotypes they could have?
Homozygous dominant (BB) or heterozygous (Bb)
A person has blue eyes (recessive trait). What must their genotype be?
bb
Two parents are crossed: one is Bb and the other is bb.
Without drawing the full Punnett square, explain the possible genotypes and phenotypes of the offspring and their probabilities.
Genotypes: 50% Bb, 50% bb. Phenotypes: 50% dominant, 50% recessive
If a Minecraft world were real, it would roughly be the size of what planet in our Solar System?
Neptune
The DNA in one human cell can stretch to over 6 feet long, yet it fits inside the nucleus.
Explain how this is possible and what structure helps make this happen.
They are tightly packed in CHROMOSOMES
Why is it helpful for organisms to have variation in traits within a population?
It increases the chances that some individuals will survive and adapt to changes in the environment
Two parents both show a dominant trait, but they have a child with a recessive trait.
Explain how this is possible.
Both parents must be carriers (heterozygous), allowing the child to inherit two recessive alleles
Why is it more useful to know someone’s genotype than phenotype when predicting offspring?
Genotype shows what alleles they can pass on, while phenotype does not
A Punnett square shows a 25% chance of a trait. If a family has 4 children and none show the trait, explain why this is still possible.
Each child is independent, so it is possible (though unlikely) that none inherit the trait
In the original 1981 arcade game Donkey Kong, what was Mario's occupation (job)?
Carpenter, NOT plumber.