Plants do not have a circulatory system like that of some animals. If a given wa
ID: 180443 • Letter: P
Question
Plants do not have a circulatory system like that of some animals. If a given water molecule did "circulate" (that is, go from one point in a plant to another and back), it would require the activity of only the xylem only the phloem only the endodermis both the xylem and endodermis both the xylem and phloem. Which of the following statements about hormones is incorrect? They are produced by endocrine glands molecules They are modified amino acids, peptides, or steroid They are carried by the circulatory system organisms They are used to communicate between different They elicit specific biological responses from target cells The endocrine system and the nervous system are structurally related. Which of the following cells best illustrates this relationship? neuron in the spinal cord a steroid-producing cell in the adrenal cortex. A neurosecretory cell in the hypothalamus A brain cell in the cerebral cortex enzymes A cell in the pancreas that produces digestive Guard cells do which of the following? Protect the endodermis Accumulate K+ directly into cells into cells Contain chloroplasts that import K+ directly loss through the stomata Guard against photosynthesis-transpiration compromiseExplanation / Answer
51. E. Botht the xylem and the phloem. While xylem is required for transport from the root tip to the leaf, phloem is required for transport in the opposite direction. In xylem, water movement is unidirectional. In phloem, the solutes generally move from the source to the sink. In order the water molecles to return, they must be transported through phloem only.
52. The incorrect statement is D. They are used to communicate between different organisms. Hormones communicate between different organs or system of the body, but not between different organisms.
53. C. The neurosecretory cell in the hypothalamus. A neurosecretory cell is a neuron which converts neural signals into chemical signals. It thus so by producing neurohoromones that travel along the axon and are released into the bloodsteam at the regions where the neurons end in blood stream.
54. E. help balance the photosythesis-transpiration compromise.