The oxygen that arose in early Earth's atmosphere was likely produced by organisms that were very similar to modern
A) plants.
B) algae.
C) fungi.
D) cyanobacteria.
E) protists.
D
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An open system in which the growth rate is maintained by adding a nutrient (present in limiting quantities) at the same rate that medium containing microorganisms is removed is called a
A. manostat. B. culturostat. C. chemostat. D. turbidostat.
Which of the following statements best compares the pedicel and receptacle?
A. The pedicel and receptacle are identical, merely two names for the same structure. B. The pedicel is haploid and the receptacle is diploid. C. The pedicel is a reproductive part of a flower and the receptacle is a vegetative part. D. The receptacle is the part of the flower that receives the pollen whereas the pedicel relays sperm to the ovule. E. The pedicel is the tip of the stem bearing the flower and the receptacle is the base of the flower.
Characterize the structure and function of antigens
What will be an ideal response?
Why is the presence of clay particles important in soil?
a. They provide macronutrients- particularly nitrogen, phosphorus, and potassium. b. They bind metal ions, which would be toxic if absorbed by plants. c. They allow water to percolate through the soil, making oxygenrich air pockets available. d. The negative charges on clay bind to positively charged ions and prevent them from leaching.