#Question id: 4863
#Unit 8. Inheritance Biology
Two genes of a flower, one controlling blue (B) versus white (b) petals and the other controlling round (R) versus oval (r) stamens, are linked and are 10 map units apart. You cross a homozygous blue-oval plant with a homozygous white-round plant. The resulting F1 progeny are crossed with homozygous white-oval plants, and 1,000 F2 progeny are obtained. How many plants of each of the four phenotypes do you expect?
#Question id: 2585
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber?
A. Tropomyosin shifts and unblocks the cross-bridge binding sites.
B. Calcium is released and binds to the troponin complex.
C. Transverse tubules depolarize the sarcoplasmic reticulum.
D. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP.
E. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane.
#Question id: 10144
#Unit 6. System Physiology – Plant
Choose the incorrect statements about photosynthesis dark reaction ?
#Question id: 4647
#Unit 11. Evolution and Behavior
The treeʹs horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Letʹs say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species. Which of the five common ancestors, labeled V—Z, has been most successful in terms of the percent of its derived species that are extant?
#Question id: 28196
#Unit 5. Developmental Biology
the tissue that produces a signal that changes the cellular behavior of the other tissue is called___