STAAR 2021: Evolution

Some organisms have genes that improve their ability to survive and reproduce. If the genes also help their offspring survive and reproduce, then which of the following will most likely increase?

• The frequency of the genes in one individual

• The frequency of the genes in the population

• The number of genes in one chromosome

• The number of genes in the species

A prey population consists of individuals with a variety of running speeds. The adaptation that allows some of these animals to run fast would be an example of natural selection if it helps them —

• survive and undergo mutations in their DNA

• lower the mortality rates of the population

• produce offspring that run at average speeds

• reproduce and increase the frequency of their genes in the population

The diagram shows light- and dark-colored beetles that live on a tree.Which result is most likely to occur to the beetle population due to predation over time?

• The number of light-colored beetles in the population will increase.

• There will be more dark-colored beetles than light-colored beetles.

• The number of light-colored beetles will decrease.

• The dark-colored beetles will move to a different type of tree.

Why are advantageous traits more likely to be passed onto offspring?

• Because the trait is an acquired phenotype.

• Because they come from dominant alleles.

• Because they come from recessive alleles.

• Because they are more likely to survive and reproduce.

What word describes a trait that helps an organism survive in its environment?

• natural selection

• mutation

• camouflage

• adaptation

Mutations are a change in what?

• DNA
• tRNA
• genotype
• phenotype

These moths are all the same species. The differences between their wings is an example of ________________

• Natural Selection
• Variation
• Homeostasis
• Extinction

Scientists can explore whether two different animal species have evolved from a common ancestor, using evidence from all of the sources below except

• analysis of strands of DNA

• comparisons of bones and muscles

• comparison of the experiences of each organism

• studies of embryos during development

The Galapagos Islands, a small group of islands off the coast of Ecuador, is home to reptiles such as the giant tortoise and the iguana. The eastern islands are much older than the islands to the west.  Which statement about the origin of these reptiles is best supported by this information?

• The ancestor of each species came from different continents at different times.
• The common ancestors of the reptiles probably came from Equador.
• The common ancestor of each species evolved in Peru and came to the islands at the same time.

In recent years "SuperBugs" (bacteria that aren't affected by antibiotics) are becoming more and more common. How could natural selection explain this?

• Superbugs survive antibiotics and reproduce

• Antibiotics cause bacteria to become superbugs

• We have always had the same amount of superbugs; modern media just discusses them more.

• There is no reliable data on the origin of super bugs.