Your friends Ben and Jane are contemplating having children and seek your genetic counsel. Ben and Jane are unrelated, but both have younger brothers with the same, extremely rare genetic trait. (In fact, Ben and Jane met at a support group meeting for children and families of children with this rare disorder.) Ben’s parents and Jane’s parents are all unaffected.          

Assume that the trait is autosomal dominant with 80% penetrance in heterozygotes and 100% penetrance in homozygotes. If not affected, what is the probability that the child is a carrier?

#Question id: 18080

#Unit 9. Diversity of Life Forms

#Question id: 24609

#Unit 2. Cellular Organization

#Question id: 15010

#Unit 8. Inheritance Biology

#Question id: 7212

#Unit 5. Developmental Biology

The regeneration blastema forms from pluripotent stem cells called clonogenic neoblast. If cNeoblasts are essential for regeneration, their total loss should prevent regeneration. Following statements are made in respect to planaria regeneration are given below.

(A) The gene sigma/zeta is expressed by all neoblasts and has become the most common marker for their identification across planarian species.

(B)   In planaria, Wnt/β-catenin functions to establish dorsal ventral polarity of the regenerating flatworm.

(C)   Inhibition of Wnt/β-catenin signaling in regeneration-deficient species yields fully functional regenerated heads.

(D)   If β-catenin is eliminated from the posterior (tail-forming) blastema by RNA interference, that blastema will form a tail.

Which of the above statements are true?

#Question id: 26983

#Unit 10. Ecological Principles