Test — Cumulative exam Answers

In rock layers, jellyfish fossils are found lower than trilobite fossils, and trilobite fossils are found lower than ammonite fossils. What can be determined from this information?

Cystic fibrosis is a genetic disorder. It is a recessive trait that is determined by two alleles. Suppose two parents each carry at least one recessive allele, but neither of them has cystic fibrosis. Which statement reflects the likelihood of a child of these parents having cystic fibrosis?

Darwin’s finches evolved on an island. What is the main reason that islands often provide good examples of evolution?

Which base is found only in DNA?

Which are different forms of the same gene?

Populations of organisms that exhibit a high degree of variation have a greater chance for survival than populations of organisms that show little variation. This statement is

Red-green color blindness is an X-linked recessive disorder. What is the probability of the offspring having red-green color blindness for the cross that is represented by the Punnett square?

Changes in the gene pool can occur due to various mechanisms. In 1989, a large oil spill occurred in Prince William Sound, Alaska, when the Exxon Valdez oil tanker ran aground. Approximately 11 million gallons of oil were spilled and spread 1,300 miles along the Alaskan coastline. The damage from the oil spill affected thousands of animals in the area, including killer whales, harbor seals, sea otters, fish, and sea birds. Which mechanism most likely affected the gene pools of the organism populations in the areas around the oil spill?

A student argues that two species of birds are the same species because they have similar body structures, similar DNA, and similar beaks. Another student argues that the birds are different species because they have different color patterns and have a different mating season. Which piece of evidence supports the second student's argument?

Why do a chicken embryo and a cow embryo look very similar even though the adults do not?

Which best describes a gene?

Which scenario breaks the law of segregation?

It can be seen on a cladogram that modern birds and reptiles share a common ancestor. Select the piece of evidence that best supports this idea.

Which is an issue that governments must consider before passing conservation policies?

In roses, red flowers and long stems are dominant traits. A rose plant that is homozygous for both red flowers and long stems is crossed with a rose plant that is heterozygous for red flowers and homozygous for short stems. What percentage of the offspring will exhibit red, long-stemmed flowers?

The fossil record shows that the average size of black bears was large during cold glacial periods and got smaller during warmer time periods. What is this an example of?

Which term refers to all areas of Earth where life exists?

A strand of DNA contains the bases adenine, cytosine, cytosine, and guanine, in that order. Which would be the order of the bases on the opposite strand of DNA?

Variations within a species are an important part of Charles Darwin's theory of evolution. Which example can be explained by individual variation?

Which is a cause of desertification?