The first plants evolved rapidly during which time period?
a. Triassic
b. Silurian
c. Devonian
d. Ordovician
e. Carboniferous
b
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If cell walls or are not perforated,
a. xylem and phloem will not be able to function as vascular tissue. b. gas exchange will not occur across the stomata. c. water will not enter the epidermal cells of the root. d. the terminal bud will not cause the stem to elongate. e. all of these will occur.
Which of the following statements about monosaccharide structure is true?
a. A six-carbon sugar is called a pentose. b. Aldoses and ketoses differ in the position of their hydroxyl groups. c. All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms. d. Monosaccharides can be classified according to the spatial arrangement of their atoms
What is the stage of cell division in a diploid organism if you see seven chromosomes, each consisting of a pair of sister chromatids?
A) mitosis prophase B) mitosis anaphase C) meiosis I anaphase D) meiosis II prophase
All the following are correct about detergents, except
A. they are active in the presence of organic matter. B. in low concentrations they are bacteriostatic. C. they are ineffective against the tuberculosis bacteria. D. the most effective ones are positively charged. E. they are polar molecules that act as surfactants.