Ecology overview - review of lessons 1 - 7 quiz- multiple choice- === 1. which of the following are biotic factors and which are abiotic factors? (1 point) b. algae and fungi are biotic; temperature and rainfall are abiotic. === 2. why is it useful for an ecologist to identify the keystone species in an ecosystem? (1 point) c. the keystone species is critical to maintaining the stability of an ecosystem, and changes in its population indicate changes in ecosystem health. === 3. competition over resources occurs between organisms. c. attempting to occupy the same niche. === 4. the lowest trophic level in an ecosystem. b. has the greatest biomass === 5. what is true of the energy that is passed from one trophic level to the next in a food chain? b. about 10% of the stored energy of one level becomes stored energy at the next higher level. === 6. autotr

Fan egg cell containing the (n+1) number of chromosomes combines with a sperm cell containing the (n) number of chromosomes, what is the result of this union? a) all future somatic cells of the organism will contain the (2n + 1) number of chromosomes. b) all future somatic cells of the organism will contain the (2n - 1) number of chromosomes. c) only certain somatic cells of the organism will contain the (2n + 1) number of chromosomes. d) all future somatic cells of the organism will contain the normal diploid number of chromosomes.

Which statement best describes the role of religion and culture in ancient medicine?

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).