Question

Multiple choice: All of the following statements about evolution are true except:

A) It is a change in the frequency of particular alleles within a population over time.

B) Every mutation occurring in an organism’s DNA leads to genetic changes that are beneficial and adaptive.

C) When an animal selects a mate based on particular features or behaviors, the offspring that result will be better adapted than would those arising from a purely random mate choice.

D) Darwin’s theory of evolution easily accounts for simple refinements in form (i.e., adaptations); however, novel or dramatic changes in form require an understanding of modern discoveries taken from cell and molecular biology.

Multiple choice: The phrase “ontogeny recapitulates phylogeny”:

A) Explains why developmentally, human hearts don’t form directly having 4-chambers, rather they undergo a sequential formation that begins with 2, then 3, then 4 chambers.

B) Is used to explain why all chordates, including humans have gills at some time during their embryonic development.

C) Supports the idea that physical features you acquire during your lifetime can be passed on to your offspring.

D) Has been entirely rejected by the scientific community as an obsolete idea.

E) a and b

Choose the FALSE statement:

A) Relative to the fossil record or comparative morphology, the closeness of the evolutionary relationship between humans and chimpanzees is most clearly demonstrated by comparing their DNA sequences.

B) The idea that “ontogeny recapitulates phylogeny” provides a basis for studying an organism’s evolutionary history by examining the details of its embryonic development.

C) Fossilization is such a common occurrence in nature that we should expect to find a complete record of the entire history of life going back at least 3.5 billion years.

Answer 1

Answer- B) statement is false as mutation is any random change in the genome of an organism which may or may not be advantageous. So, stating that every mutation leads to a beneficial or adaptory change is completely false.

While, the other statements are true. Evolution is a change in the frequency of particular alleles over time within a population and selection of specific features in the mate can result in the better adapted offsprings than the purely random ones. Also, as Darwin stated the theory of the 'survival of the fittest' and adaption in response to the changing environmental conditions, it easily accounts for simple refinements in form.

Answer- E) a and b as the Phrase "Ontogeny repeats phylogeny" explains both the given statements. This is a hypothesis stated by Ernst Haeckel that the development of an animal's embryo, from fertilization to gestation or parturition (ontogeny), goes through stages resembling successive mature or adult stages in the evolution of the animal's remote ancestors (phylogeny). Thus, this recapitulation theory explains both the phenomenon mentioned in the A) and B).

Answer- C) is a false statement because of the following reasons:

• Fossilization is not that common occurence in nature because certain biologial structures require more specialized and rare conditions to fossilize, numerous important species or groups of animals may never fossilize.
• Also hard body parts can be more easily preserved than soft body parts, explaining why there are more fossils of animals with rigid body parts, such as vertebrates, echinoderms, and certain groups of arthropods.
• Due to the geochemistry, errors in excavation, and limited vertebrate diversity, very few fossils have been found in the period from 360 to 345 million years ago. The number of species identified through fossils is less than 1% of all species that have ever lived.