According to the diagram, arrange the steps in correct order: 

1. DNA is then digested by the Cas9 nuclease at specific points on both DNA strands. 

2. Homologous recombination to repair the break and incorporate the new DNA sequence then follows. 

3.The nuclease Cas9 is targeted to DNA by a guide RNA consisting of a specific 20 nucleotide spacer/targeting sequence (crRNA).

 4. That identifies the DNA to be modified, linked to a trans-activating (tracrRNA) sequence necessary for the recruitment and stability of Cas9 nuclease.

#Question id: 3271

#Section 3: Genetics, Cellular and Molecular Biology

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

#Question id: 3273

#Section 3: Genetics, Cellular and Molecular Biology

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

#Question id: 3274

#Section 3: Genetics, Cellular and Molecular Biology

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?

#Question id: 3275

#Section 3: Genetics, Cellular and Molecular Biology

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 ________.

#Question id: 3276

#Section 3: Genetics, Cellular and Molecular Biology

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.

#Question id: 3277

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following describes the most likely order of events in allopatric speciation?