In mammals, embryonic cells form an inner cell mass that will become the body of the embryo and a layer of surrounding cells that will become the chorionic membrane and placenta. What are these surrounding cells called?
A. Yolk
B. Trophoblast
C. Blastodisc
D. Blastocoel
Answer: B
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Which of the following is true concerning the life cycle of a moss?
a. Gametophytes are nutritionally dependent upon sporophytes. b. Emerging gametophytes arise from germinated spores. c. The zygote is protected within specialized tissues of the sporophyte. d. Spores are produced within reproductive bodies called antheridia.
Which of the following male organisms do. NOT contain XY chromosomes?
a. mice b. fruit flies c. horses d. pigs e. moths
Which of the following plants is an annual?
a. carrot b. Queen Anne's Lace c. foxglove d. cabbage e. iris
Which of the following statement is TRUE?
A. Endospores allow a cell to attach to surfaces within the host. B. Endospores are extremely resistant structures that can survive high temperatures. C. Endospores are used by bacteria for reproduction (binary fission). D. One bacterial cell produces manyendospores.