Abiallelic locus, aa, has allele frequencies of a = 80% and a=20% in a certain population. another biallelic locus, bb, has allele frequencies of b = 90% and b = 10% in the same population. both loci are found to be in hardy-weinberg equilibrium. a recessive digenic disorder (100% penetrant) occurs only when one has the aabb genotype. it’s found that 15 people out of 10,000 in this population have the disorder. what was the expected frequency of the disorder? (assume that the "a" locus and the "b" locus segregate independently.)

Every compound can be represented by a chemical formula. a chemical formula is the set of symbols showing the elements that make up a compound and their proportions. water’s chemical formula is h 2 2 o. that means a molecule of water contains two atoms of hydrogen and one atom of oxygen chemically bonded. a molecule is a group of two or more atoms bonded together. molecules can range in size from two to thousands of atoms. a molecule of a compound is the smallest unit of that compound. every molecule of water has all the physical and chemical properties of water. that’s because every molecule of water is made of the same elements in the same proportions: two hydrogen atoms and one oxygen! which of the following is a true statement? a every molecule of the same compound will have different properties. b every molecule of a compound has the same proportion of elements. c molecules can be physically separated into smaller units of a compound. d molecules cannot be represented by chemical formulae.

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.

What happens when a scientific theory is shown to be an accurate description of a phenomenon?