In summer squash, spherical-shaped fruit has been
shown to be dominant to elongated fruit. On one
occasion two different spherical varieties were
crossed and produced all disk-shaped fruits. When
these hybrid disk-shaped fruits were crossed, they
produced 75 disk-shaped fruits, 48 spherical fruits,
and 9 elongated fruits. Explain these results. What will be an ideal response?
Answer: 9 D__ S__ disk, 3 D__ ss spherical, 3 dd S__ spherical,
1 dd ss elongated; the presence of both dominant genes produces
disk, whereas the presence of either one of the genes as
homozygous recessive produces spherical, and both recessive
produces elongated fruit.
You might also like to view...
Which of the following statements about mycorrhizae is correct?
A. Endomycorrhizal fungi constitute a monophyletic group. B. The hyphae of ectomycorrhizal fungi penetrate plant root cells. C. Endomycorrhizal fungi provide plant roots with nutrients, whereas ectomycorrhizal fungi do not. D. Endomycorrizal fungi receive carbohydrates from plants, whereas ectomycorrhizal fungi do not. E. Endomycorrhizal fungi branch extensively in the soil surrounding plant roots, whereas ectomycorrhizal fungi do not.
Electroporation ____
a. exposes cells briefly to rapid pulses of electrical current to induce transformation b. exposes cells to calcium ions to induce transformation c. exposes cells to calcium ions to induce transduction d. inserts the foreign DNA into chloroplast DNA e. inserts the foreign DNA into mitochondrial DNA
An animal with a gastrointestinal tract is the ___________.
A. jellyfish B. planarian C. hydra D. sponge E. earthworm
Which of these adaptations to a terrestrial existence evolved most recently?
A) vascular tissue B) seeds C) lignin D) cuticle