Why do humans and other animals have two nostrils?
What will be an ideal response?
Humans evolved from ancestors with bilateral symmetry including two nostrils, and so we also have two nostrils. In much the same way that having ears on both sides of our heads are advantageous, two nostrils might have been advantageous to our animal ancestors because they allow better determination of the location from which a chemical emanates in three-dimensional space. Also, two nostrils provide more surface area for olfactory epithelium, and so more have more sensory cells for chemoreception.
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Which muscle functions to adduct and rotate the femur as well as extend the tibia?
A) gluteus medius B) gracilis C) sartorius D) pectineus
Failure of the superior neural tube to close causes a fatal condition called
A. anencephaly. B. spina bifida. C. SIDS. D. striae gravidarum.
Skeletal muscle is called ___________, because it is usually subject to conscious control.
A. excitable B. contractile C. striated D. voluntary E. isometric
Which of the following correctly describes the vestibular projection pathway to the brain?
A. Vestibular nerve - vestibulocochlear nerve - vestibular nuclei - thalamus - cerebral cortex B. Vestibulocochlear nerve - vestibular nerve - vestibular nuclei - thalamus - cerebral cortex C. Vestibular nerve - vestibulocochlear nerve - thalamus - vestibular nuclei - cerebral cortex D. Vestibulocochlear nerve - vestibular nerve - thalamus - vestibular nuclei - cerebral cortex