Molecular Basis of Inheritance Questions and Answers

17 When Gregor Mendel crossed a heterozy gous tall plant with a heterozygous tall plant DD Dd tall plant dd short plant DD x Dd 1 Point D d D d 100 of the offspring were short 100 of the offspring were tall 75 toll 35 ohart

If BB Black WW White BW Pink BW x BW X What are the chances of the offspring being pink 1 Point B W 100 75 50 25 B W

When Gregor Mendel crossed a homozy gous dominant tall plant with homozygous recessive short plant DD Dd tall plant dd short plant DD x dd 1 Point D D d d 100 of the offspring were short 100 of the offspring were tall

Some traits are found only on the X chromo some This is known as 1 Point O codominance O incomplete dominance sex linked trait

First Position A U C A G UUU UUC UUA UUG CUU CUC CUA CUG U Phe GUU GUC GUA GUG Leu Leu AUU AUC lle AUA AUG Met UCU UCC Val UCA UCG CCU CCC CCA CCG ACU ACC ACA ACG GCU GCC GCA GCG Codon Chart Second Position C Ser Pro Thr shown below Ala A UAU Tyr UAC UAA stop UAG stop His CAU CAC CAA CAG Gin AAU AAC Asn AAA AAG Lys G UGUJ Cys UGC UGA stop UGG Trp CGU CGC CGA CGG AGU AGC AGA AGG Arg GAU Asp GAC GAA GAG Glu An original DNA strand had the following sequence Ser Arg GGU GGC GGA GGG Gly SORGSG U G MCACUCAG Sequence TAC TTT GGC ATG CCT CGC AAA Based on the codon chart which DNA sequence is an example of a silent DNA strand TAC TTT GGG ATG CCT CGC AAA TAC TTT GGC ATC CCT CGC AAA C TAG TTT GGC ATG CCT CGC AAA Third Position D TAC TTT GGC ATG CCT CGC AAA

Students are comparing the processes of transcription and translation in a cell Drag each process feature to its associated column in the chart Transcription occurs at a ribosome reads RNA to make a protein Translation occurs in the nucleus uses DNA to make RNA links amino

Sickle cell anemia is a recessive disorder which commonly affects the red blood cells RBCs of individual from Central and Northern Africa The faulty protein of the RBC causes these cells to deform into a sickle shape and block blood flow If a homozygous dominant parent reproduces with a carrier heterozygous of the sickle cell allele s what are the possible genotypes of their child Dominant allele Parent s Genotypes Phenotype frequencies sickled RBC tunica BBC Recessive allele X Genotype frequencies homozygous dominant

Allele Frequenc 9 P Allele Moths Genotype Frequency q2 Typica 2pq Carbonaria p D Carbonaria Genotype dd Dd DD Initial Allele Frequency Color Light Dark Dark 0 70 0 30 Moths Released 490 420 90 Initial Frequency 0 49 0 42 0 09 G5 Allele Frequency Round to 2 decimal places 0 91 Frequency G5 0 01 1 8 0 9 0 1 Number of Moths G5 848 838

the surprising results of this experiment Griffith hypothesized that something in the heat killed S strain cells must have changed the R strain cells so that they were able to produce capsules and therefore become highly virulent Furthermore Griffith found that these living cells were able to reproduce and pass on their capsule and virulence to subsequent generations He now knew that whatever had changed these cells was heritable During this time very little was known about DNA so Griffith was never able to determine what caused the change in the bacteria but he termed this phenomenon transformation Griffith s surprise results did not lead to a vaccine but his work was not done in vain This famous experiment was a significant contribution to the scientific community because it helped spur other scientists to discover that DNA was the transforming principle We will come back to this important study later in the unit when we look at transformation more closely For now we will focus on learning more about DNA and the discoveries that this experiment led to 8 Review the experiment conducted by Griffith Identify the control group the experimental group and independent and dependent variables fail ban bosglattu al siq LAHUA

Which nucleotides are purines Adenine Cytosine Thymine Guanine

2 Prior to developing a complete model of a DNA molecule many scientists made discoveries about the chemical composition of DNA a Describe two discoveries Edwin Chargaff and his team made about DNA 2 points b How did Chargaff s work affect Watson and Crick s three dimensional model of DNA 1 point c How did Watson and Crick determine the shape of DNA molecules 1 point d What is one scientific question Erwin Chargaff might have asked himself while designing his experiments about DNA 1 point

9 In banded snails a brown shell color is dominant over a yellow shell color Unbanded shells are dominant over banded shells Two snails with unbanded brown shells mate with each other Both are heterozygotes for shell color and shell banding Their offspring have four different phenotypes unbanded brown shell banded brown shell unbanded yellow shell banded yellow shell How does the law of independent assortment explain the offspring phenotypes Use parent gamete genotypes and offspring genotypes to support your answer 4 points

DODT DNA Replication DNA polymerase Leading strand RNA primer Lagging strand Helicase DNA polymerase Original DNA 41 a Use the model to explain the order of events during DNA replication Include the terms DNA polymerase RNA primer and helicase in your explanation 3 points b How are the new leading and lagging strands built differently Why are they built differently 2 points

Use Scenario I to answer the following questions Review the Punnett Square analysis in the presentation before attempting the problem Scenario 1 R red eyes and r sepia eyes 1 If the male has sepia eyes what is his genotype 8 2 If the female has red eyes and is homozygous what is her genotype 3 What is the predict genotype and phenotype of their offspring Which generation is their offspring part of Please show your work 4 If two of their offspring are mated what is the predicted outcome of their offspring Which generation is their offspring part of Please show your work

2 What is the difference between the P F1 and F2 generations

In cattle the allele for white coat color W and the allele for red coat color R are codominant A heterozygote has the roan coat color Two cows with the following genotypes are crossed WWX RR What is the expected phenotypic ratio of the offspring OA 2 red 0 roan 2 white OB 0 red 4 roan 0 white O C 3 red 1 roan 0 white D 1 red 2 roan 1 white

Which law or principle states that an individual s two alleles for a gene separate during gamete formation OA Law of independent assortment OB Principal of dominance OC Law of segregation OD Principal of true breeding

In banded snails shell color is controlled by a gene with a dominant allele for brown color B and a recessive allele for yellow color b The presence of bands is controlled by a gene with a dominant allele that produces no bands U and a recessive allele that produces five bands u The two genes do not occur on the same chromosome Snails with the following genotypes are crossed BBUU Bbuu What is the probability that the offspring will have the BBUU genotype OA 0 50 OB 0 00 O C 1 00

Who concluded that factors now known as alleles are transferred from parents to offspring during reproduction O A Gregor Mendel OB Erwin Chargaff O C Oswald Avery Albrecht Kongel

What did Oswald Avery discover that changed scientists understanding of how traits are inherited OA A transforming principle found in cells can be inherited and passed to offspring B Parents pass on factors that produce specific traits in offspring C Heritable information is carried by DNA and not by proteins or RNA D Dominant alleles may mask recessive alleles in offspring

QUESTION 11 You have discovered a single sequence of the complemen CCT

cs Review Guide 1 In Mendelian Genetics if a dominant allele is present the dominant trait will or will not be expressed if there is a recessive allele present 2 Define homozygous 3 Define heterozygous 4 Gametes such as egg and sperm are diploid or haploid in their number of chromosomes 5 If RR Rr right handed and rr left handed Use the Punnett square to cross a left handed dad with a heterozygous right handed mom What are the chances of having left handed offspring 6 If RR Rr right handed and rr left handed Use the Punnett square to cross a heterozygous right handed dad with a heterozygous right handed mom What are the chances of having left handed offspring

SB3 b A plant with round seeds is crossed with another plant with round seeds Round are dominant over oval seeds When two heterozygous round seeded plants are crossed what is the expected outcome of their offspring assuming random chromosome segregation Complete a Punnett square to get the correct answer O The round shaped plant will most likely appear 75 of the time O The round shaped plant will appear 100 of the time O The oval shaped plant will most likely appear 75 of the time O The oval shaped plant will appear 50 of the time

SB3 a A red flower and a white flower can be expressed on a plant depending on genetics Which outcome would indicate codominance as the inheritance pattern for flower color in this species All offspring are white All offspring are red All offspring of a red X white cross would be spotted with red and white both being expressed O All offspring of a red X white cross would be pink

2 2 points Circle the differences between DNA and RNA on both images 0 Phosphate group O DNA Nitrogenous base A G C or T Sugar deoxyribose Thymine T RNA P 0 CH 0 Phosphate group Nitrogenous base A G C or U OH Om Uracil U Sugar ribose

Macmillan Learning A small generic section of the primary structure of an a helix is given by amino acid amino acid amino acid3 amino acid amino acid amino acid amino acid Which amino acid residue s backbone forms a hydrogen bond with the backbone of the fifth 5th residue Which peptide segment is most likely to be part of a stable a helix at physiological pH Tyr Trp Phe Val Ile Pro Leu Thr Pro Trp O Gly Arg Lys His Gly O Lys Lys Ala Arg Ser O Gly Gly Gly Ala Gly

The RNA World theory states that RNA preceded DNA as the primary information storing molecule and life on early earth consisted entirely of RNA molecules Which of the following provides the most direct support for this theory A B C D RNA molecules consist of only four nucleotides making their synthesis and replication relatively simple RNA molecules do not usually form a complementary double helix and therefore require less biomolecular resources to synthesize The chemical versatility of RNA molecules allows them to store information as well as to fold into different functional shapes The ribose sugar on the RNA nucleotide contains a hydroxyl group that increases its chemical stability

Which of the following best describes the specificity of interaction between a substrate and an enzyme A B C D The shape and charge of the substrates are compatible with the active site of the enzyme The interaction between an enzyme and a substrate is dependent on environmental conditions The enzyme undergoes a conformation change during the interaction but the substrate does not The available energy of reactants is greater than the available energy of the product

A trait that helps an organism survive and reproduce is called a n O adaptation O illegal O mutation O selection

Q3 Is there a difference between the following questions and how you could solve them In a population the frequency of A 0 4 What is the frequency of A A 5 min 0 4 b In a population in Hardy Weinberg equilibrium the frequency of A What is the frequency of A A

When a change occurs in a gene it is called a n recessive gene allele mutation chromosomal disorder

ered swer 1 Unaffected male Affected male A Unaffected female Affected female Figure 1 A pedigree of three generations of a family that have a high frequency of a particular genetic condition Figure 1 shows the inheritance of a particular genetic condition in three generations of one family Which of the following best explains the observed pattern of inheritance The condition is passed randomly because of the independent assortment of chromosomes The condition is passed from fathers to sons via a Y linked gene The condition is passed from mothers to sons via an X linked gene The condition is passed from mothers to offspring via a mitochondrial gene

ypic 3 When true breeding red snapdragons Show work here genotype RR are crossed with true breeding pundai vino is AMG Jalquil white snapdragons genotype WW the resulting F offspring are all pink heterozygotes genotype RW If a self cross of the F generation produces an F generation of 1 2 600 offspring how many of the F are expected 2 to be red

1 In some breeds of mice yellow coat color is Show work here dominant to gray coat color Inheriting two copies of the dominant yellow trait however is lethal during embryonic development In a cross between two yellow mice what proportion of the offspring is expected to be yellow What proportion is expected to be gray What is the phenotypic ratio of the offspring mob sition on odtons 2100tle 2000 suo in sag ono norw bolled in 2

Why is it that for X linked genes fathers can pass their X linked alleles to ALL of their daughters but NONE of eir sons mice

3 Why are there more X linked disorders than there are Y linked disorders star les lould gnibond sind a nodw

5 Explain why both mitochondrial and chloroplast DNA are only inherited by offspring through the mother atlov the pigne

2 What is it called when one gene at one locus affects another gene at another locus A common example is coat color in animals

A small rural fishing village in the state of Zulia Venezuela has the highest concentration of people suffering from Huntington s Disease in the world In 1979 scientists caught wind of the alarming rates of HD in this area Several research teams were sent to meet with the people in the village and take blood samples to examine their DNA The data that was collected and continues to be collected from the people of this village has led to astounding advancements of our knowledge of the disease which will hopefully one day lead to better treatments prevention and maybe even a cure Scientists were able to obtain over 4 000 blood samples for DNA analysis as well as an immense amount of clinical data i e family history symptoms etc Using this data they were able to determine the source of the devastating genetic mutation a single woman who helped found the village ten generations prior Currently there are over 18 000 individuals living in this area of Venezuela who have Huntington s Disease Examine Figures 1 and 2 below then answer the corresponding questions bab inanimob Is to have chlide 00 II of Onset Charcot Marie Troth they might have more of an effect than you imagine your genes matter to anyone besides you Do they affect the rest of the population Well as it turns out mutation known as a triplet expansion The triplet expansion occurs on a mutated HTT gene where a triplet of Huntington s disease HD is a rare autosomal dominant neurodegenerative disease caused by a type of the disease individuals who have 6 35 CAG repeats will be unaffected while people with 40 or more CAG repeats are nucleotides CAG is repeated several times The number of repeats also plays an important role in the age of onset of guaranteed to develop symptoms of the disease HD is unique in that the symptoms and onset of the disease begin in adulthood and usually appear around the age of 30 45 this means that many people who have the disease have already had kids and passed on the genetic trait before their symptoms even appeared Symptoms of HD include a loss of motor control altered personality and a decline in overall cognitive function The disease is fatal and there are no current treatments to slow the progression of the disease IIIth IV Fig 1 Pedigree depicting four generations of a Venezuelan Huntington s Disease family Circles represent females and squares represent males A shaded symbol means they are affected with the disease A slashed symbol means the individual has died 80 60 I 40 Ione I 20 pitice of 11 44 48 Triplet Repeat Length CAG T T 52 56 38 T 60 of the triplet Fig 2 Box plot representing the age of onset vs the expansion The larger the boxes the more data that fell within that range

a b c b 17 What is similarity of F and V type ATPases They are proton active transporters have the similar structure membrane and catalytic domeins their subunits rotate 18 What determines signaling role of Ca ions in the cell a Cellular metabolism is very sensitive to small intracellular Ca concentration change what plays important role in signalingpathways activation of enzymes and muscle relaxation contraction process Ca ATPase is electrogenic pump Ca ion low concentration in cytosol Different type of Ca ion transporters Ca ATPases gated Cal channels secondary active antiporters c d They have similar structure and transport heavy metals They are proton active transporters and catalyze ATP synthesis They are proton and anion active transporters

Some characteristics are determined by Inheritance Height weight and skin pigmentation are examples of traits controlled by many genes 5 Sex linked traits genes carried on the sex chromosomes Genes on the X chromosome are said to be X linked and are considered sex linked Examples are red green colorblindness and hemophilia Females carry the alleles and males carry the alleles 6 Fill in the Punnett square to the right and write the phenotype sex of all possible offspring colorblind male normal females normal male Genotypes Phenotypes Blood Types A B AB 0 7 A man with type AB blood marries a woman with type O blood Give the genotypes and phenotypes of all possible offspring A B XRY x XRXE Type J R normal r colorblind

Codon Worksheet Use the codon table to complete the DNA triplets mRNA codons tRNA anticodons and amino acids in the table below Second Letter 1st letter GGC AAA GTA TAT DNA triplet CCA UUU Phe UCU UCC UCA UCG U UUC UUA UUG CUU C CUC CUA CUG AUU A AUC AUA AUG GUU G GUC GUA GUG Leu CCU Leu CCC CCA CCG ACU lle ACC ACA Met ACG Val C GCU GCC 2 What codon means start AUG GCA GCG mRNA codon AAG CAG ACA AGC UAU Ser UAC UAA UAG Pro Thr Ala Questions 1 What 3 codons act as termination signals A CAU CAC CAA CAG Tyr UGU Cys U UGC GAU GAC GAA GAG Stop UGA Stop A Stop UGG Trp G His Gin AAU Asn AAC AAA AAG Lys Asp Glu UUA tRNA anticodon CUC AUU COU CGC Arg CGA CGG GGC JOAO JOAO JOAO UUAG AGU Ser AGC AGA AGG GGA GGG Arg GGU GGC Gly 3rd U letter Amino Acid

2 Dimples are a dominant trait If a man who is homozygous dominant for dimples has a child with a woman who is heterozygous for the trait what will the genotypic ratios of the child be

Deletion and insertion may cause what s called a FRAMESHIFT meaning the reading frame changes changing the amino acid sequence SUBSTITUTION one base is substituted for another Complete the boxes below Classify each as either Deletion Insertion or Substitution AND as either frameshift missense silent or nonsense hint deletion or insertion will always be frameshift Original DNA Sequence mRNA Sequence Amino Acid Sequence If a substitution changes the amino acid it s called a MISSENSE mutation If a substitution does not change the amino acid it s called a SILENT mutation If a substitution changes the amino acid to a stop it s called a NONSENSE mutation Mutated DNA Sequence 1 What s the mRNA sequence What will be the amino acid sequence Will there likely be effects wid TACAC CTTGGCGA C GA CT AUGUGGAA CCC CU GOUGA Meth 71ypto Aspa Arg List Stop libde Mutated DNA Sequence 2 TACGAC C What s the mRNA sequence What will be the amino acid sequence Will there likely be effects TACATCT M CGACT What kind of mutation is this Mutated DNA Sequence 3 TACAC CTTAGCGACGACT What s the mRNA sequence What will be the amino acid sequence Will there likely be effects ACGACT What kind of mutation is this Mutated DNA Sequence 4 TACAC CTTGGCGACTACT What s the mRNA sequence What will be the amino acid sequence What kind of mutation is this What kind of mutation is this Circle the change Circle the change Circle the change Circle the change

6 A sequence of DNA is shown below Determine the complementary strand A A T T T A Strand Complementary Strand also have a Phosphate group C T G A G C 7 Can you predict which base comes next in the strand of DNA above Why or why not C G

e Is this is a silent mutation or a missense mutation Explain Hint Silent mutations have no effect on the amino acid 1 point

Chemically how does RNA differ from DNA List three ways 12pt Paragraph BIUA

Which of the following types of mutation could potentially create extra idling copier of existing genes which could become new genes Choose all that applies O retroposition O unequal crossing over Opoint mutation

14 2 points In domestic cats some genes that control coat color are located on the X chromosome and are inherited in a sex linked manner Black fur is dominant XF and orange fur is recessive X If a black female cat XFX has offspring with a male orange cat XY what percentage of their male offspring will have black fur A 100 B 75 C 50 D 25

13 2 points Assume that hair shape in domestic dogs is a single gene autosomal trait with two alleles where having straight hair is dominant H and having curly hair is recessive h If a straight haired dog Hh is crossed to another straight haired dog Hh what percentage of the offspring will have curly hair A 100 B 75 C 50 D 25