A ball of about eight cells formed about 50 to 60 hours after fertilization is called a(n) ________.
A. embryo
B. zygote
C. morula
D. blastocyst
Answer: C
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When a female is pregnant, there is a lot of
A. FSH present in the blood. B. LH present in the blood. C. HCG present in the blood. D. All apply.
Oxygen debt in muscles may develop because of
A. the inability of myoglobin molecules to store enough oxygen when skeletal muscles are used strenuously for a minute or two. B. too much oxygen used in forming pyruvic acid when skeletal muscles are contracted strenuously for a minute or two. C. the inability of respiratory and circulatory systems to supply enough oxygen to skeletal muscles when used strenuously for a minute or two. D. too high a concentration of oxygen in the atmosphere.
The process of dissolving bone and returning its minerals to the bloodstream is known as ________
A) mineralization B) mineral deposition C) ossification D) crystallization E) resorption
The external ear ends at the ________.
A. auricle B. tympanic membrane C. external auditory canal D. tragus