Place the three primary cell layers of an embryo in order, from superficial to deep
a. ectoderm ? endoderm ? mesoderm
b. ectoderm ? mesoderm ? endoderm
c. endoderm ? ectoderm ? mesoderm
d. endoderm ? mesoderm ? ectoderm
e. mesoderm ? ectoderm ? endoderm
ANSWER: b
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Where is the auxin receptor ABP1 located in plant cells?
a. cell wall b. cytoplasm c. endoplasmic reticulum
d. plasma membrane e. nucleus
A signal outside a cell triggers changes in the transcription and translation inside the cell through
A) post-translational editing. B) signal transduction pathways. C) protein breakdown.
In experiments by Greene and colleagues (1987 ) with the tephritid fly Zonosemata vittigera and the jumping spider Phidippus apacheanus, the purpose for gluing housefly wings onto the bodies of the tephritid fly was to ________
A) test for the effect of wing surgery in preventing predation B) test for effect of wing markings in preventing predation C) control for the effect of wing waving in preventing predation D) test for the effect of wing shape in preventing predation
Which of the following best describes the ploidy level of the cells found in the embryo sac after fertilization?
A. There are haploid, diploid, and triploid cells. B. All cells are polyploid. C. All cells are triploid. D. All cells are diploid. E. The ploidy level varies among species.