Placental mammals give birth to more fully developed offspring than marsupial mammals and therefore have a greater chance of survival. This helps to explain why placental mammals from North America displaced many native South American marsupial mammals when a land bridge formed between the two continents.
a. true
b. false
Answer: a. true
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One of the pyrimidine bases in a DNA molecule is adenine
__________________ Indicate whether the statement is true or false.
Each homeobox codes for a protein functional region that binds to a specific DNA sequence and
thereby affects translation. Indicate whether the statement is true or false.
According to the fossil record, tetrapods arose from ____
a. acanthodians b. conodonts c. osteolepiforms d. placoderms e. ostracoderms
Which of the following statements is NOT true about the life cycle of flowering plants?
A. The female gametophyte is the seed. B. The female gametophyte is retained within the body of the sporophyte parent generation. C. The sporophyte produces heterospores. D. The sporophyte is diploid. E. The male gametophyte is the pollen grain.