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TLS Online TPP Program

#Question id: 767

With respect to how miRNAs work, which, if any, of the following statements, is false?

#Unit 1. Molecules and their Interaction Relevant to Biology

  1. An miRNA is initially composed of two RNA strands, a passenger strand that will be destroyed and a complementary RNA, the guide strand, that is required for it to work.

  2. an active miRNA regulates target protein-coding genes by binding to complementary sequences in the mRNA

  3. A single miRNA normally binds to transcripts from just one target gene

  4. A single type of mRNA can be regulated by multiple different miRNAs.

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TLS Online TPP Program

#Question id: 15192

#Unit 8. Inheritance Biology

Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ca and ck. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.
Based on the concepts of recessivity, determine whether ck and ca were dominant or recessive alleles by crossing the true-breeding albino hamsters  with the true-breeding sepia hamsters. From the resulting F1 progeny phenotype, what would be the ratio of F2 phenotype
TLS Online TPP Program

#Question id: 15191

#Unit 8. Inheritance Biology

Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ck and ca. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.
Based on the concepts of dominance, determine whether ck and ca were dominant or recessive alleles by crossing the true-breeding sepia hamsters to true-breeding black hamsters. From the resulting F1 progeny phenotype, what would be the ratio of F2 phenotype
TLS Online TPP Program

#Question id: 15190

#Unit 8. Inheritance Biology

The recessive mutant allele that causes cystic fibrosis is much more frequent in Caucasians population than in other world populations. Some scientists believe heterozygotes must have had a survival advantage during plagues such as cholera that occasionally swept through this population. What concept does this illustrate?
TLS Online TPP Program

#Question id: 15122

#Unit 8. Inheritance Biology

Which of the following is the best example of overdominance?
TLS Online TPP Program

#Question id: 15121

#Unit 8. Inheritance Biology

Which of the following examples would NOT be consistent with a gene dosage effect?
TLS Online TPP Program

#Question id: 15116

#Unit 8. Inheritance Biology

In a rare blood type referred to as the Bombay phenotype, individuals are unable to attach the A or B antigens to their red blood cells. Individuals that are homozygous recessive for gene "H" have the Bombay phenotype and their blood type is type "O" regardless of their ABO genotype. This is an example of what extension of Mendelian inheritance?