TLS Online TPP Program

#Question id: 12908


Which statement is incorrect about CRISPR?

#Unit 13. Methods in Biology
  1. It  was first identified as an adaptive immunity pathway in prokaryotes providing resistance to bacteriophage and analogous to the RNA interference process found in eukaryotes. 
  2. It does not utilize double-stranded sequence-specific breaks and does not  repair using HDR via homologous recombination.
  3. The system consists of two parts, a short synthetic guide RNA ( gRNA) and a nonspecific double-stranded endonuclease termed Cas9. 
  4. It is also possible to program Cas9 with multiple guide RNAs to allow multiplex site-specific editing for designing large deletions, inversions and translocations.
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TLS Online TPP Program

#Question id: 3271

#Unit 11. Evolution and Behavior

Consider hemophilia A, a clotting disorder caused by an X-linked recessive allele with a frequency (q) of approximately 1 in 10,000. The frequency of the disease among females and among male respectively

TLS Online TPP Program

#Question id: 3272

#Unit 11. Evolution and Behavior

Calculate the frequencies of the XO and X+ alleles respectively for this population.

TLS Online TPP Program

#Question id: 3273

#Unit 11. Evolution and Behavior

The number of forward mutations is equal to the number of reverse mutations then

a) Population is in equilibrium for forward and reverse mutation rates

b) The population is being in Hardy–Weinberg equilibrium

c) No further change in allelic frequency

TLS Online TPP Program

#Question id: 3274

#Unit 11. Evolution and Behavior

The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when they mate among themselves, they are rarely successful in producing offspring. What can you infer from this information?

TLS Online TPP Program

#Question id: 3275

#Unit 11. Evolution and Behavior

When imbalances occur in the sex ratio of sexual species that have two sexes (that is, other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of ________.

TLS Online TPP Program

#Question id: 3276

#Unit 11. Evolution and Behavior

Which of these conditions are always true of populations evolving due to natural selection?

Condition 1: The population must vary in traits that are heritable.

Condition 2: Some heritable traits must increase reproductive success.

Condition 3: Individuals pass on most traits that they acquire during their lifetime.