A double-ring nitrogenous base found in DNA and RNA
What will be an ideal response?
Adenine (A)
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The common species name of the virus is based on the
A. presence or absence of a nuclear membrane. B. type of nucleic acid it contains. C. disease the virus causes. D. geographic area it is found.
The result of double fertilization in an
angiosperm is
a. two embryos. b. an embryo and a megaspore c. an embryo and endosperm. d. an embryo and a pollen grain. e. an embryo and a female gametophyte.
Fertilization of a secondary oocyte normally occurs in the
A. ovary. B. vagina. C. uterine tube. D. uterus. E. peritoneal cavity.
Which of the following statements is true about scientific theories?
1.A theory is a related set of hypotheses that form a broad-ranging explanation of many phenomena. 2.Theories can not be rejected. 3.Once established, theories can not change. 4.Scientists must not change their minds and replace theories in light of new evidence.