Genetics Basics
Alleles
Punnett Squares
Genetics Mystery
Misc.
100
A small segment of DNA that codes for a specific trait is called a...
Gene
(Also acceptable: Allele, which is a type of gene)
100
What is an allele?
One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
100
If a genotype appears once on a punnett square, what percent chance do we have of having that offspring?
25%
100
Where does Kelly get her hitchhiker's thumb from?
Her father.
100
What material contains our genetic code?
+100pt if you can pronounce the scientific name.
DNA (Deoxyribonucleic acid)
200
The passing of traits from parent to offspring is called...
Heredity
200
If an allele is represented by a capital letter, what kind of trait does it represent?
Dominant
200
In dogs, a solid coat (S) is dominant to a patterned coat (s). Cross a homozygous dominant mom and a homozygous recessive dad. What percentage of the puppies will have a solid coat?
Daily Double
100% solid
200
Does Kelly have blue eyes? Where do you think she got them from if she does?
Nina has brown eyes. Her father gave her an allele for blue.
200
One of two or more forms of a particular gene
Allele
300
Where do new traits in a population come from?
Daily Double
Mutations
300
What is it called when you have two of the same allele type?
Homozygous
300
In rabbits, black fur is dominant to white fur. If you cross a BB male with a Bb female, what are the possible genotypes and phenotypes of the offspring?
Genotypes: BB and Bb.
Phenotypes: Black
300
Can Kelly pass freckles on to her offspring? Explain.
She can't because she has two non-freckle alleles, but if the father had freckles, then they could.
300
Why do we use Punnett Squares?
To predict the likelihood of different genetic outcomes
400
Which DNA bases combine with one another? (Nucleotides: adenine (A), guanine (G), cytosine (C), thymine (T))
A-T
G-C
400
What does the notation "Aa" mean to a genetic scientist? (What is the term for this pairing?)
Heterozygous (one of each)
400
In guinea pigs, short hair, S, is dominant to long hair, s. If both guinea pigs are heterozygous for short hair, what are the possible genotypes and phenotypes of the offspring? What is the percent chance for each type?
Daily Double
Genotypes: SS (25%), Ss (50%), ss (25%)
Phenotypes: Short (75%) and long (25%)
400
Could Kelly's future children have blue eyes? Why or why not?
Yes, if the father has blue or heterozygous brown eyes, their children could have blue eyes because Kelly has an allele for blue.
400
What is a mutation? Are mutations good/bad?
Any change to an organism's genetic code. Can be good, bad, or neutral.
500
Explain this: What is the difference between sexual and asexual reproduction? How would the offspring be different?
Sexual reproduction = 2 parents, genetic diversity
Asexual reproduction = 1 parent, exact clone
500
Does Kelly have more dominant or recessive traits? How many of each?
Dominant: tongue, eyes, thumb, hairline (4)
Recessive: freckles, earlobes (2)
500
Complete a Punnett square for the following scenario: A heterozygous dad crosses with a homozygous recessive mom. What are the possible genotypes? (Use R as your allele)
Genotypes: Rr and rr
500
For each trait, what is Kelly's genotype and phenotype?
Freckles: ff -- no freckles
Tongue: TT -- can curl tongue
Eyes: Bb -- brown eyes
Thumb: Hh -- hitchhikers thumb
Earlobes: ee -- attached earlobes
Hairline: WW -- Widow's peak
500
How has our understanding of genetics grown since Gregor Mendel’s pea plant experiment? Use vocabulary words (ex: alleles, traits, dominant, recessive) to support your explanation
Mendel did not fully understand heredity and had no idea about DNA and alleles like we do today. However, Mendel was able to determine the dominance of yellow and green pea plants by cross-breeding for a few generations. The frequency of each color helped Mendel determine that yellow is dominant to green. If you cross-breed yellow pea plants, you can get both green and yellow. If you cross-breed green, you only get green. Our understanding of alleles today helps us understand why these outcomes happen due to our understanding of DNA, genes, and alleles.