Because they are morphologically simple, Psilotophyta (whisk ferns) have traditionally been thought to be a basal group in the radiation of land plants
Molecular phylogenies have challenged this hypothesis and support the alternative hypothesis that they_____.
A) are the sister group to the seed plants
B) represent a grade rather than a monophyletic group
C) have lost complex structures in this lineage
D) represent a lineage that forms a monophyletic group with Lycophyta
Answer: C
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Animals that help other animals of the same species _____
A) have excess energy reserves B) are bigger and stronger than the other animals C) are usually related to the other animals helped D) are always male E) have defective genes controlling their behavior
Which of the following statements is true regarding polyploidy in plants?
A. Autopolyploids are thought to be derived from plants of the same species. B. Allopolyploids are thought to be derived from plants of the same species. C. Polyploidy is more likely to be seen in mammals than plants. D. Hybridization events between plants cannot result in an alteration of chromosomal number.
In vertebrates, external fertilization (select all correct choices):
A. is common among mammals. B. cannot occur in marine (salt water) conditions. C. is found in some fish and amphibians. D. involves releasing gametes directly into a wet environment. E. is a form of asexual reproduction.
The majority of a shark's brain is devoted to processing signals of:
a. touch. b. olfaction. c. taste. d. electricity. e. vision.