SOLVED

41. During which period of prenatal development do most major structures, such as the heart, develop in rudimentary form? a. embryonic period b. fetal period c. germinal period d. zygotic period 42. The digestive system, lungs, and some other internal organs develop from which of the following layers of cells present in the embryo? a. ectoderm b. mesoderm c. endoderm d. zygoderm 4 The skin, sense organs, and the brain develop from which of the following layers of cells present in the embryo? a. ectoderm b. mesoderm c. endoderm d. zygoderm 44. The muscles, blood, and the excretory system develop from which of the following layers of cells present in the embryo? a. ectoderm b. mesoderm c. endoderm d. zygoderm 45. If a baby were born with malformed eyes and ears as the result of a problem very early in development, the most likely cause would be with the development of the: a. ectoderm b. mesoderm c. endoderm d. placenta 46. If a baby were born with no bowel and with complications involving the small intestines as the result of a problem very early in development, the most likely cause would be with the development of the: a. ectoderm b. mesoderm c. endoderm d. placenta 47. If a baby were born with an incompletely formed digestive system and lung problems as the result of a problem very early in development, the most likely cause would be with the development of the: a. ectoderm b. mesoderm c. endoderm d. placenta 48. Which of the following developmental events occurs earliest in the prenatal period? a. the baby is able to hear b. the baby is able to see c. the heart starts beating d. the neural tube develops into a three-part brain 49. An advertising campaign urges pregnant women to get good prenatal care by saying that all of the structures that we recognize as human (including arms, legs, eyes, internal organs, and a beating heart) have already developed early in pregnancy. Having studied prenatal development, you know that the most accurate statement is that these structures are present, at least in rudimentary form, by: a. the end of the second week of pregnancy b. the end of the second month of pregnancy c. the end of the fourth week of pregnancy d. the end of the fourth month of pregnancy 50. Suppose a friend calls you and tells you that she has had a miscarriage during the fourth month of her pregnancy. Technically, her miscarriage would be termed: a. spontaneous abortion b. term abortion c. mid-term abortion d. developmental abortion