A) Each homeotic gene has a variable region and a sequence called the homeobox that is very similar in all such genes.
B) They have been found in almost all eukaryotic organisms.
C) All homeotic genes are thought to be derived from an original DNA sequence that has been highly conserved in evolution because of its importance to animal evolution.
D) They are sequentially arranged on the chromosome in the same sequence they are activated during development of the embryo in Drosophila.
E) All the answer choices accurately describe homeotic genes.
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Multiple Choice
A) It contains enzymes that digest a pathway for the sperm through the zona pellucida.
B) It contains lipids that digest a pathway for the sperm through the zona pellucida.
C) It contains enzymes that digest a pathway for the sperm through the corona radiata.
D) It contains lipids that digest a pathway for the sperm through the corona radiata.
E) It causes the zona pellucida to become the fertilization membrane.
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Multiple Choice
A) they collect in the organs and skin, forming large molecules that interfere with organ function.
B) they donate electrons to molecules that are nearby, like DNA and proteins, causing damage to the molecule.
C) free radicals combine together and attack DNA.
D) free radicals combine with oxygen, reducing the functionality of the mitochondria.
E) they speed up metabolic processes, causing the organs to wear out faster.
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Multiple Choice
A) oval windows.
B) bursa.
C) sutures.
D) septa.
E) fontanels.
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Multiple Choice
A) embryonic signposts
B) morphogen genes
C) cytoplasmic segregation routes
D) induction genes
E) fate maps
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Multiple Choice
A) Colostrum provides proteins and antibodies to the baby.
B) Breast-fed babies are less likely to develop stomach and intestinal illnesses, including diarrhea, during the first 13 weeks of life.
C) Suckling causes uterine contractions that help reduce the uterus to its normal size.
D) Breast-feeding uses up calories that can help a woman return to her normal weight.
E) All of the answer choices are advantages of breast-feeding.
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Multiple Choice
A) not true because there is an equal contribution from both parents.
B) true because the egg contains more than just DNA and the sperm only contributes DNA.
C) not true because the egg only contributes DNA, while the sperm contributes enzymes from the acrosome and mitochondria.
D) true because the mother's blood flows into the umbilical cord and, therefore, the baby shares the mother's blood.
E) true because it is possible for a woman to become pregnant without the sperm.
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Multiple Choice
A) morula
B) blastula
C) gastrula
D) zygote
E) neurula
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Multiple Choice
A) becomes the umbilical blood vessels in humans.
B) is a structure composed of two germ layers.
C) provides nourishment to the chick embryo.
D) is involved in gas exchange in the chick embryo.
E) becomes the chorionic villi in humans.
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Multiple Choice
A) FSH; anterior pituitary
B) estrogen; ovary
C) progesterone; corpus luteum
D) HCG; trophoblast
E) GnRH; hypothalamus
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Multiple Choice
A) gives rise to umbilical blood vessels.
B) contains a fluid-filled central cavity.
C) is the expanded end of the gastrula.
D) has three germ layers.
E) is the fertilized egg.
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Multiple Choice
A) oval opening
B) venous duct
C) arterial duct
D) umbilical artery
E) umbilical vein
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True/False
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Multiple Choice
A) Neurons are extremely sensitive to oxygen deficiency, so loss of brain function may occur due to narrowing of the blood vessels rather than aging.
B) With age, some sensory receptors require more stimulation to function at the same level as before.
C) Strength in the muscles that control breathing may be lost, leading to breathing difficulties.
D) Osteoporosis, the loss of bone density, can be lessened or prevented by making good lifestyle choices.
E) All of the answer choices are true.
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Multiple Choice
A) the total life cycle of any animal.
B) the formation of the shape of the body.
C) the mechanism by which gametes are formed.
D) a study of the beginning and ending of life.
E) the study of aging.
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Multiple Choice
A) epidermis of the skin
B) cardiovascular system
C) urinary system
D) digestive system
E) endocrine system
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Multiple Choice
A) umbilical cord
B) allantois
C) yolk sac
D) embryo
E) chorion
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Multiple Choice
A) induction genes.
B) cleavage genes.
C) differentiation genes.
D) homeotic genes.
E) master genes.
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Multiple Choice
A) yolk sac
B) amnion
C) embryo
D) umbilical cord
E) chorion
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Multiple Choice
A) first
B) second
C) third or fourth
D) six or seventh
E) eighth or ninth
Correct Answer
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