Exam 13: Evidence of Evolution

If many human genes differ in about 10% of their bases from another species' same genes and substitutions occur at an estimated rate of 2% per one million years,approximately how many years have passed since the two species diverged?

The abundant remains of ammonites in Oklahoma indicate that Oklahoma was

If an isotope's half-life is 100 years,then

Any gene,when mutated,that leads to an organism with structures in abnormal or unusual places,is referred to as a(n)________ gene.

The femur in a snake and pelvis in a whale are examples of

Relative dating uses ________ to estimate how old a fossil is.

When a land bridge formed about 70 million years ago,marsupial mammals moved into South America and displaced many of the placental mammal species.

The wings of a bat and an insect are examples of

The fossil record is often incomplete,in part because scientists will never be able to discover some of the fossils that are buried deep in the earth and in part because some living things fossilize more readily than others.

The fossil record indicates that at one time marsupials were common to both Australia and South America,but today most South American marsupials have become extinct.The most probable explanation for marsupials being common to Australia yet not very common to South America today is that

In a fruit fly embryo,the end that becomes the head contains high amounts of the protein bicoid.What may happen if you injected high levels of bicoid in the other end of the embryo?

Amphibians,birds,and mammals look the most similar as

Which of the following pairs radioactive isotopes is used in radioactive fossil dating?

Fossils may be

Placental mammals give birth to more fully developed offspring than marsupial mammals and therefore have a greater chance of survival.

During which period of the Paleozoic era did the first winged insects evolve?

The techniques used to study molecular evolution are based on the comparison of nucleotide and amino acid sequences among species.

Which of the following is most likely to be preserved as a fossil?

-In the section "Investigating Life: Evolving Backwards," what was hypothesized about the loss of legs in modern-day snakes?

The half life of ¹⁴C is 5,730 years.11,460 years after an organism dies what percent of the initial ¹⁴C will still be present in the organism bones?