Genetics 340 Exam 1

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.

.05 use binomial equation P(x)=(n!/(n-x)!x!)p^x*p^(n-x)

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

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 use conditional probability: P(A/B) P(TT)/P(TT,Tt,Tt)= (1/4)/(1/4)*(1/4)*(1/4) = (1/4)/(3/4) =4/12 =1/3

What is the organization of Eukaryotic chromosomes (in order)?

1. DNA double helix 2. DNA wrapped in Histones 3. Nucleosomes coiled into a chromatin 4. Further condensation of chromatin 5. Duplicated chromosomes

Prokaryotes contain a __1__ chromosome, and eukaryotes contain ____2___ chromosomes.

1. Double stranded circular 2. Double stranded Linear

What are the 3 stages of transcription

1. Initiation 2. Elongation 3. Termination

Your chromosomes are located ___1___ and they are made of ___2____ .

1. inside the nucleus, 2. DNA

What is the probability that III-4 is a carrier (Rr)?

1/2 (draw punnet square)

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

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 dominant?

1/3

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 F1 generation has green peas?

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 F2 progeny is expected to be white?

1/4

Explain The Bacterial Transformation Principle

1928 Fredrick Griffith concluded a transforming principle must be responsible for a heat killed virulent strain of pneumococcus transforming a non-virulent strain into a pathogenic one. (late found DNA was the transforming principle.)

What is the probability that III-3 is a carrier (Rr)?

2/3 (draw punnet square)

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

If a genome contains 22% adenine, how much of the genome is cytosine?

28%

How long would the peptide be that is translated from this mRNA sequence: 5'- AUGGGCUACCGA -3'?

4 amino acids

Transcribe the following DNA sequence (non template strand): 5'-ATGGCCGGTTATTAAGCA-3'

5'-AUGGCCGGUUAUUAAGCA-3'

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%

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

Cross together two double heterozygous parents for plant height and flower color (genotypes: SsWw for both parents; S = tall, s = short, W = blue, and w = white.) What is the probability that a randomly selected offspring will be tall and have blue flowers?

9/16

What is X-ray crystallography?

A method of observing patterns formed by x-rays shot through a crystal of a substance. Used to determine the 3-D structures of many proteins.

What is the probability of having 4 girls in a row?

(1/2)*(1/2)*(1/2)*(1/2)= 1/16

In the binomial probability distribution formula, there are three unique variables. What does each one stand for (in the order of p, n, x)?

Probability of success, number of trials, number of successes

Describe Translation

Process where the information carried by mRNA is used to produce proteins. Requires; mRNA template, Ribosomes, tRNA, and various enzymatic factors.

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

The idea that for any particular trait, the pair of alleles of each parent separate and only one allele from each parent passes to an offspring is Mendel's Law of:

Segregation

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 one green seed for every yellow seed. 1:1 ratio

Which of the following is true about genes that are located on different chromosomes?

These genes are inherited independently of one another.

Which statement about analogies is correct?

They are derived by similar environmental constraints.

What is true about organisms that are a part of the same clade?

They evolved from a shared ancestor.

What is the process by which RNA is synthesized from a DNA template?

Transcription

Alternate forms of a gene are called _______.

alleles

Mendel's law of Independent Assortment describes the independent movement of _______ into ______ during meiosis.

alleles of different genes, gametes

Daughter cells produced by mitosis _______.

are genetically identical to the parent cell

What is a homologous structure?

features that overlap both morphologically (in form) and genetically.

Meiosis produces ________ daughter cells.

four haploid cells

Genotype refers to the ______________________ of an individual.

genetic makeup

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?

hhxhh

What do scientists use to apply cladistics?

homologous traits

Study Resource: Website to help with using parsimony

https://evolution.berkeley.edu/evolibrary/article/usingparsimony_01

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.

Why do scientists apply the concept of maximum parsimony?

to decipher accurate phylogenies

At metaphase I, homologous chromosomes are connected only at what structures?

Chiasmata

Which of the following events is unique to prophase I of meiosis?

Chromosome condensation

The division of the cytoplasm following mitosis to form two new cells is called?

Cytokinesis

Where does translation take place in eukaryotic cells?

Cytoplasm

In Griffith's experiments, what made the harmless R cells grow capsules when exposed to heat-killed S cells?

DNA

What is the correct sequence of steps in the central dogma?

DNA --> RNA --> Protein

Name the 8 major components of DNA

DNA is comprised of Nucleotides, Nucleotides are comprised of" 1. Deoxyribose (5-carbon sugar) 2. A phosphate group (giving DNA a negative charge) 3. A nitrogen base, which is comprised of: i. Adenine, ii. Thymine, iii. Guanine, vi. Cytosine

he Central Dogma states DNA turns into RNA and RNA turns into protein.

False DNA is used as a template for transcription and RNA is translated into Protein

How many different types of gametes could an organism with the genotype AABbCc produce?

Four. (ABC, Abc, AbC, ABc)

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

How did Mendel get the peas to cross-fertilize?

He kept them apart and pollinated them by hand.

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?

HhxHh

A recessive trait will be observed in individuals that are ________ for that trait.

Homozygous

What is the difference between Horizontal and Vertical gene transfer?

Horizontal= gene transmission between organism without parental reproduction. Vertical= Gene transmission from parents to offspring through reproduction.

In which nuclear division process do sister chromatids segregate?

In mitosis and Meiosis II

In which of the following pairs do both evolutionary processes introduce new genetic variation into a population?

Mutation and gene flow

Translate the following mRNA transcript: 5'-AUGCCGUCAGGGUGA-3'

Met - Pro - Ser - Gly - Stop

Describing a person as having hemophilia is to indicate his or her ______.

Phenotype

The observable traits expressed by an organism are described as its ________.

Phenotype

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?

AArrx aaRr

What are the types of gametes that can be produced by an individual with the genotype AaBb?

AB, Ab, aB, ab

A molecule of RNA (ribonucleic acid) contains the bases _______.

Adenine, Guanine, Cytosine, and Uracil

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.

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.

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 the Hershey-Chase experiment radioactive Sulfur was used to...?

Be incorporated into the phage protein coat because some amino acids contain sulfur

Why do your chromosomes come in pairs?

Because one member of each pair came from mother and the other from the father.

What are the possible values for the probability "P(A)"?

Between 0 and 1, including both 0 and 1

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

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.

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.

Besides growth, what must happen before a cell divides?

DNA replication.

If a muscle cell of a typical organism has 32 chromosomes, how many chromosomes will be in a gamete of that same organism?

Daughter cells will have half the number of original chromosomes =16

Rosalind Franklin's photograph 51 shows what aspect of DNA?

Double Helical Structure

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.

If an allele has a frequency of 1:

It is found in 100% of the population

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 having rounded 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.

Law of segregation

Where does transcription take place in human cells?

Nucleus

What is the probability that IV-1 is affected (rr)?

P(III-3=Rr)*P(III-4=Rr)*P(IV-1=rr) =(2/3)*(1/2)*(1/4) =(2/24) =(1/12)

What is the probability that the following pair of parents will produce the indicated offspring? TTRrYy x TtRrYy -> TTrrYY

P(TT)=(1/2), * P(rr)=(1/4) * P(YY)= (1/4) Using Multiplication rule: (1/2)*(1/4)*(1/4) =1/32

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

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

Where are ribosomes found in eukaryotes vs prokaryotes?

Ribosomes are found in the Endoplasmic Reticulum of Euks. Ribosomes are found in the cytoplasm of Proks.

In the figure, "Letter B" represents:

Sister chromatids

What is the Chargaff Rule?

The amount of Adenine= The amount of Thymine. The amount of Guanine= The amount of Cytosine. A=T and G=C (for DNA) A=U and G=C (for RNA) (*U=Uracil) A,G are purine (double ringed) (Held by 2 hydrogen bonds) U,C,T are Pyrimidines (Single ring structures) (Held by 3 hydrogen bonds)

What 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.

What is Genetic code?

The relationship between corresponding amino acid nucleotide codons and amino acid is encoded by more than one triplet nucleotides. 3 of the 64 total codons are termination codons.

What is the process by which protein is synthesized from a RNA template?

Translation

Mutation can be defined as the addition of genetic variation that increases the hereditary diversity of a population. True or False?

True

What is the semi-conservative model of DNA

Two strands of the double helix DNA separate during replication and each strand serves as a TEMPLATE from which new complementary strands are copied.

Under what conditions should you use the Multiplication/Product Rule and what notation should you use?

With independent events; P (A and B)

Under what conditions should you use the Addition/Sum Rule and what notation should you use?

With mutually exclusive events; P (A or B)

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

DNA replication is _______________ .

semi-conservative