Among bryophytes, only the sporophytes of mosses and hornworts have stomata, whereas stomata are missing from liverwort sporophytes. If the common ancestor of all bryophytes had sporophytes that bore stomata, then which of these might account for their absence from liverwort sporophytes? If, in contrast to early mosses and hornworts, early liverwort sporophytes had
A) more-effective transport of glucose from gametophyte to sporophyte.
B) increased robustness (i.e., thicker, more massive tissues).
C) increased nutritional independence from the gametophyte.
D) decreased need to broadcast spores long distances.
Ans: A) more-effective transport of glucose from gametophyte to sporophyte.
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A) XX B) XY C) XO D) XXY E) XXX
DNA evidence indicates that _____ were probably the first land plants
1.liverworts 2.club mosses 3.ferns 4.hornworts
Which of the following is NOT accurate in
describing a hormone? a. Hormones produced by a particular species affect only that species. b. Only those cells that have specific receptors for a hormone can respond to it. c. Hormones in general are produced by one cell and cause their effects in another cell. d. Hormones are a type of signaling molecule. e. Hormones stimulate or inhibit gene activity.
Which piece of evidence BEST supports the "multiregional evolution" model of the evolution of modern humans?
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