What is the significance of double fertilization in flowering plants? What will be an ideal response?
Concepts to Consider: Two sperm cells travel down the pollen tube into the ovary. One sperm cell
unites with the egg to form the zygote, while the other sperm cell unites with the two polar nuclei in
the ovule to form the triploid endosperm. Endosperm is a nutritive tissue for the developing embryonic
plant. Following these two cell fusions, the ovule develops into a seed, and the ovary develops into a
fruit.
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The input zone of a neuron involves the:
a. axon only b. axonal terminals only c. cell body only d. dendrites only e. cell body and its dendrites, but not the axon or its terminals
A mutant gene that produces brown eyes (bw) is located on chromosome 2 of Drosophila melanogaster, whereas a mutant gene producing bright red eyes, scarlet (st), is located on chromosome 3
Phenotypically, wild-type flies (with dull red eyes), whose mothers had brown eyes and whose fathers had scarlet eyes, were mated. The 800 offspring possessed the following phenotypes: wild type (dull red), white, scarlet (bright red), and brown. Most of the 800 offspring had wild-type eyes, whereas those with white eyes were the least frequent. (a) Using standard symbolism, diagram the cross from the P generation (brown-eyed mothers scarlet-eyed fathers) and the F1 generation. Be certain to provide the alleles of the mutant genes. (b) From the information presented above, how many white-eyed flies would you expect in the F2 generation?
All the following are important functions of the cytoskeleton EXCEPT
A) maintenance of organization in the cell. B) movement of organelles. C) maintenance of shape. D) storage of food molecules. E) assistance during cell division.
T or F: The dark banding seen in muscle tissue is the result of actin
What will be an ideal response?