Grade 10 Elite EOT 2 Exam 2

the polymerase chain reaction (PCR) is used to _____

• cut a fragment of DNA at a defined location

• join together the ends of two DNA fragments

• amplify the quantity of a DNA fragment

• separate DNA fragments in a mixture on the basis of size

Speciation results in new species. which of the following would be the best evidence that speciation has occurred?

• the new species does not live in the same part of the world as the old species

• the two species look completely different

• mating between the two species cannot produce fertile offspring

• mating between the two species produce offspring with similar characteristics

The table shows data regarding the presence (+) or absence (-) of five derived features in a variety of species.

which cladogram best represents the data in the table in terms of simplicity and accuracy?

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what is the benefit of cloning in the context of genetic engineering?

• making large numbers of recombinant DNA molecules that are all identical

• creating several copies of an organism

• replicating the human genome

• amplifying specific sequences of a DNA molecule

which statement describes punctuated equilibrium?

• over millions of years, small variations in evolving lineages slowly accumulate

• the proportions of genotypes in a population remain constant from generation to generation because of random mating

• stability is achieved when selection favors the heterozygote, while both types of homozygotes are at a relative disadvantage

• evolutionary changes consist of rapid bursts of speciation alternating with long periods in which species remain essentially unmodified

All of the following statements describe a part of the process of natural selection in animals, EXCEPT

• the individuals in a certain species vary

• the individuals that are best adapted to the environment survive and reproduce

• there is a struggle for existence

• acquired traits can be passed on to offspring

A mutation event occurs in a lentil plant seed, resulting in the new plant's pollen being unable to pollinate the plant that produced the seed, even though they are less than a meter apart. Which statement best describes this occurrence?

• allopatric speciation because the plants remain in close contact

• allopatric speciation because there is a significant geographic barrier

• sympatric speciation because it is the simplest form of speciation

• sympatric speciation because the plants are not separated

The cladogram in the image was created based on the morphological features of species I, II, III, and IV. A specific gene found in all four species recently had its DNA sequenced. The sequencing will provide additional information for answering which of the following questions?

• is species I the common ancestor of species II and III?

• does species I contain the greatest number of vestigial structures?

• are species III and IV the most closely related?

• should the positions of species III and IV be reversed?

The effects of a violent storm caused a small number of crocodiles to be deposited on 3 separate islands. which of the following best describes the effect of these crocodiles reproducing on the islands for many generations?

• interbreeding is prevented by certain behaviors unique to the crocodile species on each island

• speciation occurs as a result of bottleneck events that occurred prior to the ancestral species arrival on the islands

• hybridization between crocodiles from different islands has resulted in the various species that exist today

• the isolation limits gene flow, resulting in prezygotic isolation among the crocodiles on each island

Charles Darwin made several discoveries that lead to the theory of evolution. Which of the following statements describes the key points of this theory?

• biological structures that are more suitable to survive in an environment are most likely to be inherited

• mutations that occur are those that will help future generations fit into their envrionments

• slight variations among individuals can significantly affect the chance that an individual will survive in its environment and be able to reproduce

• genes change in order to help organisms manage with problems they encounter within their environments