In sheep the polled condition ( hornless ) is controlled by a single gene locus with two alleles. Heterozygous females are polled but heterozygous males have horns. Suppose two Heterozygous sheep were crossed. Refer to attachment for multiple choice questions.
Analysis of base composition from DNA extraction in Aspergillus niger was seen to contain 37% cytosine. Using this data predict the % of adenine. If the same were detected in Tobacco Mosaic Virus [TMV], will it be possible to predict the % of adenine. This job gives reasons.
A double stranded DNA virus has 200,000 base pairs. Determine the number of nucleotides present and the total number of complete spirals. How long will this DNA be?
Molecular weight of DNA in an autosome of human beings is 0.5 à? 10 power 12. Determine the number of deoxyribonucleotide pairs in this DNA and calculate the length in both micrometers and inches.
A solution containing 80% cytosine and 20% uracil was used to make synthetic RNAs. A bacterial cell free system produced proteins using these mRNAs in the following proportions: a) 4 times as many serine as leucine residues. b) 16 times as many serine residues as phenylalanine residues. c) 16 times as many proline resid
Convert the following mRNA segments into their polypeptide equivalents; a) 5′ GAAAUGGCAGUUUAC 3′ b) 3′ UUUUCGAGAUGUCAA 5′ c) 5′ AAAACCUAGAACCCA 3′ d) 3′ UGACCAGAUCUACCGAAA 5′
A certain gene consists of 450 nucleotide pairs. The protein product of the gene consists of 150 amino acid residues. How many codons make the 150 residues?
How many different mRNAs would specify the following amino acid sequences - a) met - phe - ser - pro b) ile - arg - phe - leu - ala [use the triplet codon chart to find the number of codons representing the amino acids]
Suppose 25,000 μm is 1 inch. Enumerate a formula to find the length of a DNA molecule in inches a) if the length is known in μm and b) only the number of nucleotide pairs is given.
DNA of a certain species of yeast has thymidilic acid content of 32.6%. If the A/T ratio is 0.97, what is the composition of deoxyadenylic acid?
In one set of Φ X phages the deoxyribonucleotide composition was A = 24.7, T = 32.7, G = 24.1 and C = 18.5. Another set of phages had the following deoxyribonucleotide composition - A = 27.6, T = 27.8, G = 22.3 and C = 22.3. a) Find the A/T, G/C ratio of the 2nd set of phages. b) What is the structure of the phage DNA wit
In a mutation experiment in drosophila, 45 mutations were detected amongst 543 males that received 2500 Roentgens (R) and 67 mutations in 649 males that received 4000R. What is the number of progeny expected in 1000 progeny of males exposed to 6000R?
Under laboratory conditions, a synthetic polyribonucleiotide was produced using a mixture of A and G with a relative frequency of 5:1 respectively. How would a scientist predict the relative frequencies in which the triplets are expected to form when the ribonucleotides form in a random linear array? Indicate which amino acid(s)
Find the number of triplet codons feasible from 4 ribonucleotides A, U, G and C containing a) no uracil, b) one or more uracils.
An animal cell has 46 post-mitotic chromosomes in each of its somatic cells. How many chromosomes should be present in the following cells- a) Mature egg, b) 1st polar body, c) Sperm, d) Spermatid, e) Primary spermatocyte, f) Brain cell, g) Secondary oocyte, h) Spermatogonium.
Cross between pure red tomato and yellow tomato produced all red F1 progeny. From the F2 progeny of 400 plants, 90 were yellow. Hypothesize that a single pair of allele is involved such that Y- = Red and yy = Yellow. Test this hypothesis using Chi square test.
In squash, disc shaped fruit is dependent on dominant gene D and elongated fruit on recessive allele d. Yellow color is controlled by dominant gene R and green color by recessive allele r. Draw a cross between the homozygous squash fruits and summarize the expected results of F2.
Garden pea producing round seeds were crossed with those producing wrinkled seeds. The result was the production of 5474 round seeds and 1850 wrinkled seeds. a) What is the original parental cross? b) Indicate the gamete types c) F1 progeny? d) What result do you expect when F1 is selfed? e) Indicate F1 selfed ga
Predict the results of the following crosses: a) Tall [dominant and homozygous] with dwarf - F1? b) Product of selfed F1. c) F1 with original tall parent. d) F1 with original dwarf parent
Avena stirigosa [oats] is a diploid species with 2n=14 chromosomes. How many different types of gametic combinations can form in this species?
A strain of Neurospora with the genotype HI is crossed with a strain with the genotype hi. Of the progeny, 50 percent are HI and 50 percent are hi. I explain how this is possible.
(a) By using the map function, calculate how many real map units are indicated by a recombinant frequency of 20 percent. Remember that a mean of 1 equals 50 real map units. (b) If you obtain an RF value of 45 percent in one experiment, what can you say about linkage? (The actual figures are 58, 52, 47, and 43 out of 200 pro
In the harlequin-chromosome technique, you allow THREE rounds of replication in bromodeoxyuridine and then stain the chromosomes. What result do you expect to obtain?
If you extract the DNA of the coliphate thetaX174, you will find that its composition is 25 percent A, 33 percent T, 24 percent G, and 18 percent C. Does this make sense in terms of Chargaff's rules? How would you interpret this result? How might such a phage replicate its DNA? Ideas are expressed.
Define the following terms: MEROZYGOTE RECOMBINANT FREQUENCY (RF) RECESSIVE PHENOTYPE SEX CHROMOSOME
Consider two-child families in which the parents have been identified as carriers of an autosomal recessive gene by virtue of having at least one child with the phenotype. When the children of many such two-child families are totaled, what proportion of children in these families will show the phenotype? (Hint: The answer is N
When a pea plant of genotype Aa Bb produces gametes, what proportion will be Ab? (Assume that the two genes are independent) (a) 3/4 (b) 1/2 (c) 9/16 (d) none (e) 1/4
Maple syrup urine disease is a rare inborn error of metabolism. It derives its name from the odor of the urine of affected individuals. If untreated, affected children die soon after birth. The disease tends to recur in the same family, but the parents of the affected individuals are always normal. What does this information
Holstein cattle are normally black and white. A superb black and white bull, Nick, was purchased by a farmer for $100 000. The progeny sired by Nick were all normal in appearance. However, certain pairs of his progeny, when interbred, produced red and white progeny at a frequency of about 25 percent. Nick was soon removed fr
Name 5 features of mRNA that can regulate its stability or translation. Indicate whether the feature regulates stability or translation.