MUTATIONS
What is the fundamental definition of a genetic mutation?
A permanent change is genetic information
In pea plants, purple flower color (\(P\)) is dominant over white flower color (\(p\)). If you cross a homozygous dominant parent (\(PP\)) with a homozygous recessive parent (\(pp\)), what percentage of the F1 generation offspring will have purple flowers?
What is the overall three-dimensional shape of a DNA molecule?
A double helix
What is the primary purpose of mitosis in multicellular organisms?
When a red-flowered snapdragon is crossed with a white-flowered snapdragon, the offspring have pink flowers. What is this pattern of inheritance called?
incomplete dominance
Which type of point mutation results in a codon being changed into a premature stop codon, halting translation early?
Nonsense Mutation
In a cross between two heterozygous guinea pigs for coat color (\(Bb \times Bb\)), where \(B\) is black and \(b\) is brown, what is the probability that an offspring will have brown fur?
1/4 (25%)
Which of the following sets contains the four nitrogenous bases found in DNA?
Adenine, Thymine, cytosine, Guinine
How many final daughter cells are produced from a single starting cell that undergoes meiosis?
In a certain breed of cattle, crossing a red cow with a white bull produces offspring with both red and white hairs mixed together (a roan coat). Which inheritance pattern does this represent?
Codominance
An insertion of two nucleotides into the coding region of an exon will most likely lead to which of the following outcomes?
In Japanese four-o'clock flowers, allele \(C^{R}\) codes for red flowers and allele \(C^{W}\) codes for white flowers. Heterozygous plants (\(C^{R}C^{W}\)) display pink flowers due to incomplete dominance. If you cross two pink-flowered plants (\(C^R C^W \times C^R C^W\)), what is the expected phenotypic ratio of the offspring?
1 red: 2 pink: 1 white
According to the standard rules of base pairing, which base always pairs specifically with Adenine (A) in a DNA double helix?
THymine
If a human somatic (body) cell has 46 chromosomes, how many chromosomes will a normal human sperm cell have?
23 chromosomes
Human ABO blood types are determined by three different alleles (\(I^{A}\), \(I^{B}\), and \(i\)). Because an individual can inherit any combination of two of these three alleles, what genetic pattern does this demonstrate?
multiple alleles
Sickle cell anemia is caused by a single nucleotide change (GAG to GTG) that substitutes glutamic acid with valine in the beta-globin protein. What class of mutation is this?
Missense mutation
Consider a dihybrid cross of pea plants heterozygous for both seed shape (\(Rr\), round is dominant) and seed color (\(Yy\), yellow is dominant): \(RrYy \times RrYy\). Assuming independent assortment, what fraction of the offspring are expected to show both recessive phenotypes (wrinkled, green seeds: \(rryy\))?
1/16
What are the three chemical components that make up a single nucleotide, the building block of DNA?
Which of the following best describes the genetic makeup of the cells produced at the end of mitosis?
Red-green colorblindness is a recessive trait carried on the X chromosome. Why are human males more likely to express red-green colorblindness than human females?
A mutation alters the invariant GU dinucleotide sequence at the 5' splice site of an intron in a pre-mRNA transcript. What is the most direct consequence?
Red-green colorblindness is an X-linked recessive trait (\(X^{b}\), with normal vision as \(X^{B}\)). If a carrier female (\(X^{B}X^{b}\)) has children with a male who has normal vision (\(X^{B}Y\)), what percentage of their male offspring are expected to be colorblind?
50%
What type of covalent bond connects the 3' carbon atom of one deoxyribose sugar to the 5' phosphate group of the next nucleotide in a DNA strand?
During which process does "crossing over" (the exchange of genetic material between homologous chromosomes) occur to increase genetic diversity?
meiosis ONLY
Human traits like height, skin color, and eye color show a wide, continuous range of variations rather than just two or three distinct categories. What type of non-Mendelian inheritance typically causes this continuous spectrum?