Although some species differences exist, the process of primary neurulation is relatively similar in all vertebrates. Primary neurulation can be divided into four distinct but spatially and temporally overlapping stages:

A. Bending of the neural plate

B. Closure of the neural tubeC. Elongation and folding of the neural plate D. Convergence of the neural folds

C. Elongation and folding of the neural plate

D. Convergence of the neural folds

What is the correct sequence?

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#Question id: 12496

#Unit 8. Inheritance Biology

A woman who has two brothers and a maternal uncle (her mother's brother) with non-specific X-linked mental retardation is referred for genetic counselling. There are no diagnostic tests available to help determine whether or not she is a carrier. Which of the following is correct?

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#Question id: 12497

#Unit 8. Inheritance Biology

In this pedigree A and B represent alleles at a marker locus closely linked to the disease locus. Affected individuals are shown as shaded. The disease status in III 1 is unknown. Which of the following is correct?

TLS Online TPP Program

#Question id: 12498

#Unit 8. Inheritance Biology

In this pedigree II 1 is affected with an autosomal recessive disorder. The disease status for II 2 and II 3 is unknown. A and B represent alleles at a locus which is tightly linked to the disease locus with recombination fraction of 0. On the basis of the linked marker genotypes II 2 can be told that: 

TLS Online TPP Program

#Question id: 12499

#Unit 8. Inheritance Biology

On the basis of the linked marker genotypes II 3 can be told that:

TLS Online TPP Program

#Question id: 12500

#Unit 8. Inheritance Biology

In this pedigree II 1 is affected with an autosomal recessive disorder. The disease status for II 2, II 3 and II 4 is unknown. A and B represent alleles at a locus which is tightly linked to the disease locus with recombination fraction of 0. On the basis of the linked markers II 2 can be told that: 

TLS Online TPP Program

#Question id: 12501

#Unit 8. Inheritance Biology

In the pedigree shown, on the basis of the linked marker results II 3 can be told that: