Elements of Genetics Exam 2 Connect homework
chromatin
The DNA-protein complex in eukaryotic cells is termed ________.
purine, double-ring
The ________ bases are adenine (A) and guanine (G), and they contain a ________ _______ structure.
pyrimidine, single-ring
The __________ bases are thymine (T), cytosine (C), and uracil (U), and they contain a ________ ________ structure.
QTL mapping
The basis of ____ _______ is the association between genetically determined phenotypes for quantitative traits and molecular markers such as RFLPs, microsatellites, and single-nucleotide polymorphisms (SNPs).
nucleus
The chromosomes of a eukaryotic cell are found in the __________.
guanosine
A nucleoside containing guanine is called _________.
thymidine
A nucleoside containing thymine is called _________.
phenotypes are continuous and do not fall into discrete categories.
A quantitative trait follows a continuum means that
The scientist will likely observe more recombinant offspring involving body color and finger length than elbow roughness and finger length. (Crossing over is more likely to occur between two genes that are relatively far apart than for two genes that are very close together.)
A scientist is studying body color, elbow roughness, and the finger length of a new alien species. Based on the location of each of these alleles, which statement is true?
linkage group
An entire chromosome is considered a ________ _________, as it contains a group of genes that are physically linked together.
euploid
An organism that has a chromosome number that is an exact multiple of a chromosome set is ________.
aneuploid
An organism with an alteration in the number of particular chromosomes, so the total number of chromosomes is not an exact multiple of a set is __________.
trisomic
An organism with one extra chromosome, (2n+1) is _________.
monosomic
An organism with one less chromosome, (2n-1) is ___________.
triploid
An organism with three sets of chromosomes (3n) is _________.
diploid
An organism with two sets of chromosomes (2n) is ________.
yellow-bodied, red-eyed males (Although a yellow bodied, white eyed female is a recombinant, given this cross, there cannot be a yellow bodied, white eyed female in the F1 progeny without a mutation occurring to allow it.)
If a gray-bodied, red-eyed female with genotype Xy+w+Xyw were mated to a gray-bodied, red-eyed male with genotype Xy+w+Y, which phenotypic class would be counted as a recombinant in the F1 progeny?
There would be twice as many in each nonrecombinant class grouping. (Hypothetically, the number of flies in each nonrecombinant grouping should be equally divided between males and females. If you do not separate the flies by gender, then the two groups should be twice as large as when you do separate the flies by gender.)
If, when counting the F1 progeny, you did not separate the two nonrecombinant (parental) progeny classes by gender, hypothetically, how many of each nonrecombinant class would then be present in those two groups?
haploid
In each species, the number of linkage groups equals the _______ number of chromosome types.
during spermatogenesis in the F1 males.
The recombinant gremlins of the F2 generation were produced by crossing over that occurred:
polygenic inheritance
The term __________ ________ refers to the transmission of a trait governed by two or more different genes.
the two strands have opposite orientation of their 5′ and 3′ ends. (The two strands of DNA are antiparallel with regard to their 5′ to 3′ directionality. When going from the top of the DNA to the bottom, one strand is running in the 5' to 3' direction, and the other strand is 3′ to 5′.)
The two strands of DNA are antiparallel, meaning that
deoxyribose, ribose
The two types of pentose sugars found in a nucleotide are __________ and __________, which are found in DNA and RNA respectively.
true
True or false: A QTL is actually a chromosomal region.
syntenic
Two or more genes that are located on the same chromosome
When two different genes are more than 50 map units apart, they follow the law of independent assortment in a testcross.
Using the above graph and your understanding of recombination, which choice best explains why the percentage of recombinant offspring plateaus at 50%?
nucleoside
When a base is attached only to a sugar, it is called a ___________.
genetic linkage
When genes that are close together on the same chromosome are transmitted as a unit
The two genes for eye color and body color obey Mendel's law of independent assortment.
Which of the following hypotheses is best to determine if the genes that Morgan studied for eye color and body color are linked or if they assort independently?
simple translocation
Which of the following occurs when a piece of one chromosome breaks off and is attached to another chromosome?
nucleotide
A __________ has three components: at least one phosphate group, a pentose sugar, and a nitrogenous base.
genetic map
A diagram that depicts the sequence of genes along a chromosome
1. cross two true-breeding strains with three different alleles 2. perform a testcross 3. collect data from the F2 generation 4. determine which offspring are recombinant 5. calculate the map distance between pairs of genes 6. construct the map
Arrange the steps to determine the order and distance between the three genes of the parental generation consisting of fruit flies that differ in body color, eye color, and wing shape.
551 (Each phenotype has a 25% probability of occurring. The observed F2 generation had a total of 2205 individuals. The expected number of offspring with each phenotype = ¼ × 2205 = 551.)
Based on the hypothesis that the two genes for eye color and body color obey Mendel's law of independent assortment, calculate the expected values of each of the four phenotypes. (total = 2205)
histone
Nulceosomes are formed from the association of chromosomal DNA and the __________ proteins.
compact
Part of the function of the proteins that are associated with the chromosomes is to _________ the DNA.
RNA
The four nitrogenous bases found in ______ are: A, G, C, and U.
DNA
The four nitrogenous bases found in ________ are: A, G, C, and T.
H1
The histone that is not directly part of the histone core is _____.
quantitative trait locus
The location on a chromosome that harbors one or more genes that affect the outcome of a quantitative trait is called a ________ ________ _______.
true
true or false: Animal breeders are most interested in narrow sense heritability, which estimates how a population will respond to selection.
false
true or false: Broad sense heritability is also called realized heritability and only considers additive gene effects on the phenotype.
true
true or false: If an inbred strain of mice has a genetic variance of zero, then it cannot respond to selection.
true
true or false: In QTL mapping, one needs variable quantitative traits and variable molecular markers.
true
true or false: It is possible to calculate narrow sense heritability using correlation coefficients. The expected genetic correlation between sibilings is 0.5
true
true or false: It is possible to have phenotypic variance without genotypic variance.
true
true or false: Wheat color is an example of polygenic inheritance with additive alleles.
true
true or false: A typical eukaryotic chromosome contains between a few hundred and several thousand different genes.
false
true or false: A typical eukaryotic chromosome is about one hundred thousand base pairs in length
true
true or false: Both inversions and translocations can lead to overall deficiencies and duplications of genetic material after meiosis.
false
true or false: Centromeres contain specialized sequences located at both ends of the linear chromosome.
false
true or false: Eukaryotic chromosomes are usually circular.
false
true or false: Eukaryotic chromosomes contain a telomere that forms a recognition site for the kinetochore proteins.
true
true or false: Eukaryotic chromosomes contain many origins of replication that are interspersed about every 100,000 base pairs.
true
true or false: Many eukaryotic species are diploid with two sets of chromosomes in somatic cells.
