A muscle contracts more strongly when lifting a 20-pound weight than when lifting a 5-pound weight. This is because more fibers are contracting, not because individual fibers contract harder.
a. true
b. false
a. true

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Recent research by marine biologists suggests that bottlenose dolphins have names for themselves. scientists played sounds they had identified as the names of particular dolphins, putting them through a synthesizer so that they did not sound like the voices of particular dolphins. the researchers found that dolphins would respond to the names of other dolphins that they were related to or associated with, but they ignored the names of strangers. this discovery suggests a much greater degree of self-awareness in aquatic mammals than was previously suspected. if this research holds up, what does it suggest about dolphins?

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.