What soil component is most important for retaining water in soil for use by plants?
a. sand
b. humus
c. clay
d. silt
e. rock
ANSWER: b
You might also like to view...
An example of a second messenger is:
a. protein kinase A. b. an ion channel. c. cyclic AMP. d. GABA. e. insulin.
G = green leaves g = yellow leaves N = naturally shapedleaves n = curly leaves Individuals with the heterozygous genotype of GgNn repeatedly produce haploid gametes consisting of the alleles GN, Gn, gN, and gn. Which law best represents this phenomenon?
A. Law of Meiosis B. Law of Dominance C. Law of Crossing Over D. Law of Independent Assortment
Some flowers have distinctive patterns that only reflect ultraviolet light and therefore are invisible to humans. Which statement about such markings is not correct?
A. Flowers with ultraviolet patterns usually appear yellow or orange to humans. B. Carotenoid pigments are responsible for the ultraviolet patterns. C. The ultraviolet patterns are highly visible and attractive to bees. D. The ultraviolet patterns repel birds and bats from the flowers. E. The ultraviolet patterns often form a conspicuous central bull's eye or identify the best landing sites.
A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes?
A) mucociliary escalator B) normal skin flora C) phagocytosis in the inflammatory response D) acidic skin secretions E) lysozyme