a 20 week old fetus can

ATI RN

Growth and Development Exam

1. A 20-week-old fetus can __________.

A. be stimulated as well as irritated by sounds
B. survive, if born early
C. breathe without oxygen assistance, if born early
D. control its own body temperature Answer: A Page Ref: 80 Skill Level: Understand Topic: Prenatal Development Difficulty Level: Moderate

Correct answer: A

Rationale: A 20-week-old fetus is able to be stimulated as well as irritated by sounds because by this stage of prenatal development, the fetus's auditory system is already well-developed. It can respond to external sounds and may even startle or move in reaction to loud noises.

2. If pregnancy does not occur, the corpus luteum shrinks, and the __________.

A. cells begin to duplicate
B. one-celled zygote multiplies and forms a blastocyst
C. germinal period lasts only about two weeks
D. lining of the uterus is discarded

Correct answer: D

Rationale: If pregnancy does not occur, the corpus luteum will shrink. As a result, the lining of the uterus is discarded through the process of menstruation. This shedding of the uterine lining is what causes menstrual bleeding. Choices A, B, and C are incorrect because they do not describe the physiological response of the body when pregnancy does not occur. The corpus luteum shrinking and the subsequent shedding of the uterine lining are part of the menstrual cycle, not processes related to cell duplication, zygote multiplication, or the duration of the germinal period.

3. During the period of the embryo, the becomes the .

A. mesoderm; nervous system, lungs, internal organs, and skin
B. chorion; endocrine system, muscles, placenta, and skeleton
C. ectoderm; circulatory system, skin, skeleton, and internal organs
D. endoderm; digestive system, lungs, urinary tract, and glands Answer: D Page Ref: 78 Skill Level: Remember Topic: Prenatal Development Difficulty Level: Moderate

Correct answer: D

Rationale: During the period of the embryo, the endoderm becomes the digestive system, lungs, urinary tract, and glands. The endoderm is one of the primary germ layers that give rise to various internal organs in the developing embryo. It plays a crucial role in the formation of organs such as the digestive system, respiratory system, and glandular structures.

4. Anoxia during labor and delivery can cause __________.

A. spina bifida
B. anencephaly
C. cerebral palsy
D. muscular dystrophy

Correct answer: C

Rationale: Anoxia during labor and delivery can cause cerebral palsy. Cerebral palsy is a group of disorders that affect a person's ability to move and maintain balance and posture. It is caused by damage to the developing brain, often due to a lack of oxygen during labor and delivery. Spina bifida (Choice A) is a neural tube defect that occurs during embryonic development and is not directly caused by anoxia during labor. Anencephaly (Choice B) is a severe neural tube defect where the baby is born without parts of the brain and skull, not typically caused by anoxia during labor. Muscular dystrophy (Choice D) is a genetic disorder characterized by progressive muscle weakness and is not directly related to anoxia during labor and delivery.

5. Professor Higgins is concerned about the findings of a longitudinal study on childhood depression that she conducted between 1985 and 2015 in New York because many of the participants witnessed the terrorist attacks on the World Trade Center. Professor Higgins is concerned about __________ effects.

A. practice
B. cross-sectional
C. dropout
D. cohort

Correct answer: D

Rationale: The concern Professor Higgins has regarding the findings of the longitudinal study is related to cohort effects. Cohort effects occur when a specific group of individuals experience a common event or circumstance that could influence the results of a study. In this case, the participants witnessing the terrorist attacks on the World Trade Center could have had a significant impact on their development and mental health outcomes, leading to cohort effects observed in the study. Choice A, 'practice,' is incorrect as it refers to the repeated performance of an activity to improve skill. Choice B, 'cross-sectional,' is incorrect as it involves data collection at a single point in time. Choice C, 'dropout,' is incorrect as it refers to participants leaving a study prematurely.