Mendelian Genetics
Punnett Squares
Mutations
Pedigrees
100
What are the Mendel's two laws of inheritance?
Law of Dominance and the Law of Segregation
100
Dennis and Laura have three sons. What's the probability that they will have a daughter?
50%
100
What type of point mutation results in a STOP codon?
Nonsense - A single base change that codes for an early or premature stop codon!
100
What two shapes are used in pedigrees and what do they represent?
Circle - females
Squares - males
200
Wavy hair is recessive to straight hair in cats. If the cat is heterozygous, what is its phenotype?
Straight hair
200
These are two terms used to describe a genotype that has two different alleles for a trait.
Heterozygous or carrier
200
After being exposed to radioactivity, a strand of DNA with the sequence ATTATCTGC has been changed to ATTCGCATCTGC. What type of mutation has occurred?
Insertion
200
How can you differentiate between an autosomal recessive and an autosomal dominant pedigree?
Dominant - The trait usually appears in every generation, both males and females are equally likely to be affected, no carriers (If an individual inherits the dominant allele, they will express the trait)
Autosomal Recessive - Skips generations: The trait often skips one or more generations, appearing more sporadically, Presence of carriers (Unaffected parents can have affected children) indicating they are carriers (heterozygous for the recessive allele), both males and females are equally likely to be affected.
300
Using the letter B/b, write the following genotypes:
Homozygous Dominant
Homozygous Recessive
Heterozygous
What are BB, bb, and Bb?
300
In a Punnett Square crossing two parents that are carriers for their brown eyes, this is the ratio of the genotypes.
BB - 25% Bb - 50% bb - 25%
or
1:2:1
300
What is the difference between a point mutation and a frameshift mutation?
Point mutations change or substitute a single base in a DNA sequence, but frameshift mutations shift entire sections of DNA when bases are added or deleted.
300
(1) Draw a pedigree that represents two parents (Bruce and Selina) and their two children (Jason and Kate).
(2) Label the pedigree with their NAMES
(2) Correctly identify Kate as a heterozygous individual and mom as affected
See board!
400
Both parents pass down the gene for hair color, but both mom and dad pass down different forms of the same genes.
(1) What are these different forms called?
(2) Identify the two forms we've used in class.
(1) Alleles!
(2) Dominant allele and recessive allele
400
Two healthy parents produce a child with the genetic disorder of cystic fibrosis, which is the result of a recessive gene. What are the genotypes of the parents? Use the letter A.
Aa - Both are heterozygous or carriers.
400
The tyrosinase protein is responsible for melanin production in living organisms. Certain frameshift mutations, such as deletions, can alter the DNA sequence entirely. If a deletion occurs in the TYR (tyrosinase) gene, it may cause the protein to stop functioning.
What is one possible effect of this mutation if the TYR gene stops working?
If the TYR gene stopped working, then living things would be unable to produce melanin, which could result in albinism!
400
Find the mistake in the pedigree!
Because both mom and dad are affected in generation 2, ALL their kids should be affected in generation 3. Which as a result would affect generation 4.