Module I
In Griffith’s experiments, what made the harmless R cells grow capsules when exposed to heat-killed S cells?
DNA
In the Hershey-Chase experiment radioactive Sulfur was used to:
Be incorporated into the phage protein coat because some amino acids contain sulfur
The experiments by Hershey and Chase helped confirm that DNA was the hereditary material on the basis of the finding that:
Radioactive phosphorus was found inside the cell
If DNA of a particular species was analyzed and it was found that it contains 27 percent of adenine (A), what would be the percentage of cytosine (C)?
23 percent
Four nucleic acid samples are analyzed to determine the percentages of the nucleotides they contain. Which of the following DNA sample(s) could be double-stranded DNA? Sample 1: A(22%), G(28%), T(22%), U(0%), C(28%); Sample 2: A(30%), G(30%), T(0%), U(20%), C(20%); Sample 3: A(18%), G(32%), T(0%), U(18%), C(32%); Sample 4: A(29%), G(29%), T(21%), U(0%), C(21%)
Sample 1
Your chromosomes are located _______ and they are made of ___________ .
inside the nucleus, DNA
A nucleotide is made of _______.
sugar + phosphate + nitrogen base
A molecule of RNA (ribonucleic acid) contains the bases _______.
adenine, guanine, cytosine, and uracil
Which of the following does cytosine pair with?
Guanine
Prokaryotes contain a _________ chromosome, and eukaryotes contain ________ chromosomes.
double-stranded circular; double stranded linear
How long would the peptide be that is translated from this mRNA sequence: 5'- AUGGGCUACCGA -3'?
4 amino acids
What is the correct sequence of steps in the central dogma?
DNA->RNA->Protein
Where does transcription take place in human cells?
Nucleus
Where does translation take place in eukaryotic cells?
Cytoplasm
Transcribe the following DNA sequence (non template strand): 5'-ATGGCCGGTTATTAAGCA-3'
5'-AUGGCCGGUUAUUAAGCA-3'
In which of the following pairs do both evolutionary processes introduce new genetic variation into a population?
Mutation and gene flow
Mutation can be defined as the addition of genetic variation that increases the hereditary diversity of a population.
T/F
True
If an allele has a frequency of 1:
It is found in 100% of the population
When male lions reach sexual maturity, they leave their group in search of a new pride. This can alter the allele frequencies of the population through which of the following mechanisms?
Gene flow
When closely related individuals mate with each other, or inbreed, the offspring are often not as fit as the offspring of two unrelated individuals. Why?
Inbreeding can bring together rare, deleterious mutations that lead to harmful phenotypes.
Which statement about analogies is correct?
They are derived by similar environmental constraints.
What do scientists use to apply cladistics?
homologous traits
What is true about organisms that are a part of the same clade?
They evolved from a shared ancestor.
Why do scientists apply the concept of maximum parsimony?
to decipher accurate phylogenies
Which one is the correct tree?
Tree A
Alternate forms of a gene are called _______.
alleles
Describing a person as having hemophilia is to indicate his or her ______.
phenotype
Why do your chromosomes come in pairs?
Because one member of each pair came from my mother and the other from my father.
How did Mendel get the peas to cross-fertilize?
He kept them apart and pollinated them by hand.
The observable traits expressed by an organism are described as its ________.
phenotype
Half of the gametes produced by an organism with the genotype Aa will receive the A allele, while half will receive the a allele. This is a demonstration of ______.
segregation
Which of the following is true about genes that are located on different chromosomes?
These genes are inherited independently of each other.
A recessive trait will be observed in individuals that are ________ for that trait.
homozygous
What are the types of gametes that can be produced by an individual with the genotype AaBb?
AB, Ab, aB, ab
How many different types of gametes could an organism with the genotype AABbCc produce?
4
Genetic inheritance is being studied in a certain species of plant in which orange flower color (O) is dominant to white (o) and round leaf shape (S) is dominant to oval (s). A true-breeding orange-flowered, round-leaved male plant (Plant A) is mated with a true-breeding white-flowered, oval-leaved female plant (Plant B) to produce dihybrid offspring plant (Plant C). Assuming normal Mendelian genetics and independent inheritance of these two traits, which gametes might be produced by Plant C?
Both OS and oS
In guinea pigs coat color is determined by a single gene with two alleles. A guinea pig from a true-breeding black strain is mated with a guinea pig from a true-breeding white strain. The F1 progeny are all black. Two of the F1 progeny are mated with each other. What proportion of the F2 progeny is expected to be white?
1/4
In guinea pigs coat color is determined by a single gene with two alleles. A guinea pig from a true-breeding black strain is mated with a guinea pig from a true-breeding white strain. The F1 progeny are all black. Two of the F1 progeny are mated with each other. What proportion of the black F2 progeny is expected to be homozygous?
1/3
The presence of short hairs on leaves is controlled by dominant allele H. Plants with genotype hh have smooth leaves. Two parental plants with unknown genotype were crossed. What are the parental genotypes if F1=32 Hairy and 11 smooth?
Hh x Hh
The presence of short hairs on leaves is controlled by dominant allele H. Plants with genotype hh have smooth leaves. Two parental plants with unknown genotype were crossed. What are the parental genotypes if F1=0 Hairy and 24 smooth?
hh x hh
Mendel imagined that seed color in pea plants is influenced by a gene with two alleles in which the allele for yellow seeds (Y) is dominant over the allele for green seeds (y). What would Mendel predict the seed colors would be from a cross of a male plant with the mixed Yy genotype with a female plant with the yy genotype?
There should be 1 green seed for every 1 yellow seed.
In apples, the allele A is dominant for a big size apple and the allele R is dominant for red color. You cross one tree that produces big yellow apples and another tree that produces small red apples. Half of the offspring trees produce big red apples and half produce big yellow apples. What are the genotypes of the parents?
AArr and aaRr
You have flipped a standard quarter 10 times and had four head and six tails come up. With that experience, what will be the chances of you getting a heads on the next flip?
50%
If a student randomly guesses at five multiple-choice questions during a BIO 340 exam, find the probability that the student gets exactly three correct. Each question has five possible choices.
0.05
What is the probability of having 4 girls in a row?
1 in 16
In a cross between two heterozygous plants (Tt x Tt), what is the probability of a plant being homozygous given that it is tall?
0.33
What is the probability that the following pair of parents will produce the indicated offspring? TTRrYy x TtRrYy -> TTrrYY
1/32
John has alkaptonuria; it "runs in the family". John and his grandmother are both homozygous for alkaptonuria. John's grandmother has two brothers and a sister. One of the brothers had alkaptonuria and his daughter is John's mother. Based on this information, John's parents are:
Both heterozygous for the alkaptonuria gene.
If John marries someone who is heterozygous for alkaptonuria, then which of the following statements is true? Remember alkaptonuria is a recessive disorder.
All of the children will inherit at least one copy of the alkaptonuria gene.
What is the probability that III-3 is a carrier (Rr)?
2/3
What is the probability that III-4 is a carrier (Rr)?
1/2
What is the probability that IV-1 is affected (rr)?
1/12
Daughter cells produced by mitosis _______.
are genetically identical to the parent cell
Besides growth, what must happen before a cell divides?
DNA replication.
The division of the cytoplasm following mitosis to form two new cells is called?
Cytokinesis
In the figure, "Letter B" represents:
Sister chromatids
Which of the following is the correct order of events in mitosis?
The kinetochore becomes attached to the mitotic spindle. Sister chromatids line up at the metaphase plate. Cohesin proteins break down and the sister chromatids separate. The nucleus reforms and the cell divides.
Meiosis produces ________ daughter cells.
four haploid
If a muscle cell of a typical organism has 32 chromosomes, how many chromosomes will be in a gamete of that same organism?
16
Which of the following events is unique to prophase I of meiosis?
Pairing of homologous chromosomes.
At metaphase I, homologous chromosomes are connected only at what structures?
Chiasmata
In which nuclear division process do sister chromatids segregate?
In mitosis and meiosis II.
In a cross between a homozygous red-eyed female fruit fly and a white-eyed male fruit fly, what is the expected outcome?
All offspring with red eyes.
In a cross between a white-eyed female fruit fly and a red-eyed male fruit fly, what is the expected outcome?
All male offspring with white eyes.
Hemophilia has an X-linked recessive pattern. It is carried on the “X” chromosome. It is only expressed phenotypically as homozygous recessive in women but men that inherit the affected chromosome will suffer from the disorder. A carrier woman (one affected X chromosome) married a man with hemophilia, and they have children. What percent of their boy children will be affected with hemophilia?
50% of the boy children.
What would a female genotype have to be for her to have the genetic disease hemophilia?
Both her X chromosomes would have to have the recessive hemophilia gene.
Congenital generalized hypertrichosis is an X-linked dominant disease. If an affected male marries an unaffected female, what is the probability of passing the hypertrichosis gene to his offspring?
p=0.5, all daughters will be affected.
Human sex-linked transmission
follows distinct patterns
In X-linked recessive inheritance, females homozygous
for the
recessive allele or males hemizygous for it display the recessive phenotype
In X-linked dominant traits, heterozygous females and
males
hemizygous for the dominant allele express the
dominant phenotype
X-linked inheritance is theterm for traits carried on the X chromosome; males have only one X and so are called hemizygous for X-linked traits
X-linked dominant trait transmission
The distinctive characteristics of X-linked dominant
traits
are:
1. Heterozygous females mated to wild-type males
transmit
the dominant allele to half their progeny of each
sex
2. Dominant males mated to homozygous recessive
females
pass the trait to all their daughters and none of their
sons
3. The trait appears equally frequently in males and females
List below all probable transfers proposed by Dr. Crick.
DNA > DNA
RNA > RNA
DNA > RNA
RNA > Protein
List below all possible transfers proposed by Dr. Crick.
DNA > Protein
RNA > DNA
List below all impossible transfers proposed by Dr. crick
Protein > DNA
Protein > RNA
Protein > Protein
The basis of Dr. Crick’s 1970 paper was to clarify the central dogma of molecular biology in response to the “Central Dogma Reversed” publication put forth by Dr. Howard Temin. According to Dr. Crick, the work of Dr. Temin suggests what?
Tumor viruses containing RNA as their genetic material can use viral RNA as a template for DNA synthesis.
The alleles of a particular gene segregate independently into individual gametes (sex cells) during meiosis.
T/F
True
You cross a pea plant with purple flowers to a plant with white flowers. The resulting offspring have a mixture of purple and white flowers. What were the possible genotypes of the parents if the purple allele is dominant (B) and the white allele is recessive (b)? (Hint: draw Punnett squares).
Parent 1: Bb, Parent 2: bb
Two diploid individuals, one homozygous and the other heterozygous at a particular gene, make babies. Which of the following statements about the offspring genotype is correct? (Hint: draw Punnett squares)
1/2 of the offspring are homozygotes and 1/2 are heterozygotes
The DNA sequence of a gene is a phenotype.
T/F
False
Consider a plant character, leaf shape. In a tree species, it has been determined that leaf shape is controlled by a single gene segregating two alleles, and havingrounded leaves is dominant to elongated leaves.
An experiment that crossed a rounded-leaf plant with an elongated-leaf plant, both from true-breeding lines, found the following results: all F1 offspring have rounded leaves. F2 offspring, which came from selfing of F1 individuals, also all have rounded leaves.
A hypothesis suggests that the law of _______ is most likely violated in this mating. Fill in the blank.
Segregation
Mendel's law of Independent Assortment describes the independent movement of _______ into ______ during meiosis.
alleles of different genes, gametes
Consider a diploid organism. What is the phenotypic ratio expected to be observed in the offspring produced by two homozygous recessive parents?
0 dominant: 1 recessive
What are the possible values for the probability "P(A)"?
Between 0 and 1, including both 0 and 1
Under what conditions should you use the addition/sum rule and what notion should you use?
With mutually exclusive events; P(A or B)
In the binomial probability distribution formula, there are three unique variables. What does each one stand for (in the order of p, n, k)?
Probability of success, number of trials, number of successes
Cross together two heterozygous parents for pea color (genotypes: Gg for both parents; G = yellow, g = green.) What is the probability that a plant in the F1generation has yellow peas?
3/4
Cross together two double heterozygous parents for plant height and flower color (genotypes: SsWw for both parents; S = tall, s = short, W = purple/violet, and w = white.) What is the probability that a randomly selected offspring will be short and have purple/violet flowers?
3/16
Under what conditions should you use the multiplication/product rule and what notation should you use?
With independent events; P(A and B)
DNA replication is classified as _______________ replication
Semi-conservative
Given this DNA template strand (3'-CTGAGGCATATCAC-5'), select the correct RNA transcript.
5'-GACUCCGUAUAGUG-3'
I mentioned an exception to the classic Central Dogma in my video. What was the exception?
RNA to DNA
The Central Dogma states DNA turns into RNA and RNA turns into protein.
T/F
False
Translate the following mRNA transcript: 5'-AUGCCGUCAGGGUGA-3'
Met - Pro - Ser - Gly - Stop
What is the process by which RNA is synthesized from a DNA template?
Transcription
What is the process by which protein is synthesized from a RNA template?
Translation
Who proposed the Central Dogma of molecular biology?
Francis Crick