Following statements regarding to feedback loops during limb development.

A. When the limb bud is relatively small, an initial positive feedback loop is established between Fgf10 produced in the mesoderm and Fgf8 produced in the ectoderm, promoting limb outgrowth.

B. As the limb bud grows, the ZPA is established, and another regulatory loop is created by inhibiting the BMP in mesoderm and maintain FGF expression.

C. In anterior region of the limb bud, Fgf8 positively regulates Etv4/5, which in turn repress Shh in this region, further reinforcing the posterior-to-anterior gradient of Shh from the ZPA.

D. In posterior region of the limb bud, Fgf8 positively regulates Etv4/5, which in turn repress Shh in this region, further reinforcing the posterior-to-anterior gradient of Shh from the ZPA.

Which of the following combinations are incorrect?

  

#Question id: 3525

#Unit 8. Inheritance Biology

In a plant, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype was crossed with rrtt plant results progeny, are

#Question id: 3526

#Unit 8. Inheritance Biology

In garden peas, the allele for tall plants (D) is completely dominant to the allele for dwarf plants (d) and the allele for violet flower color (W) is completely dominant to the allele for white flower color (w). In a cross between a tall violet plant, with the genotype DDWw, and a dwarf white plant, what phenotypic ratio of the progeny would be expected from this cross?

#Question id: 3527

#Unit 8. Inheritance Biology

Which of the following genetic cross would produce 1/4 yellow round, 1/4 yellow wrinkle, 1/4 Green round and ¼ Green Wrinkle seeded plant?

#Question id: 3528

#Unit 8. Inheritance Biology

Consider the following cross:

A/a ; B/b ; C/c ; D/d ; E/e  X a/a ; B/b ; c/c ; D/d ; e/e

What proportion of progeny will phenotypically resemble the first parent?

#Question id: 3529

#Unit 8. Inheritance Biology

Mendel crossed tall and round seeded pea plants with dwarf and wrinkle seeded pea. The F1 plants were all tall and round seed. What is the probability of tall plant with wrinkle seed in F2 generation?

#Question id: 3530

#Unit 8. Inheritance Biology

Mendel’s law of segregation, as applied to the behavior of chromosomes in meiosis, means that: