Biology 1023 Chapter 32 Questions and Answers

Plants require carbon dioxide to produce sugar during photosynthesis. When a plant's stomata remains closed, which of the following can occur? Answer decrease in sugar production The xylem and phloem act much like the human circulatory system. Which of the following statements regarding the xylem and phloem is incorrect? Answer The phloem's only function is to transport sugars from the roots to the leaves. Gravitropism and phototropism are a result of a hormone called _______. Answer auxin Giant redwood and other woody plants contain cellulose and _______. Answer lignin In addition to water and sugar, plants require certain nutrients to grow. Certain bacteria present in fertile soil help plants obtain _______. Answer nitrogen Plant hormones, called gibberellins, are used in agriculture to do all of the following EXCEPT ___________. Answer promote abscisic acid Each fall, most deciduous trees produce vibrant colored leaves. Which of the following best explains why a leaf may turn yellow in the fall? Answer The green pigment in the leaves decreases, allowing the yellow pigment to stand out. Auxin is a hormone produced by plants that causes _______. Answer elongation of cells Which of the following is a method developed by plants to prevent selfpollination? Answer male and female reproductive organs located at different heights chemical barriers to fertilization of eggs Most plants are hermaphrodites, which means they ___________. Answer contain both male and female reproductive organs All of the following are pigments found in leaves EXCEPT _______. Answer chlorophyll anthocyanin xanthophylls caroten