Quiz 2 Selection, Adaptation, Mutation, Variation

A  About 2% of genetic infromation is contained in DNA, and the rest in chromosomes that are free of DNA.

B  Only small part of DNA contains genetic information, because most information is stored in RNA.

C  Our DNA contains exons that contain coding sequences (genes) and DNA contains introns that are non-coding sequences.

A  Only mass extinctions and genetic drift can reduce competition among species.

B  Specialization on a specific niches partitions ressources and increases diversity.

C  Evolving to obtain more competitive abilites and replacing competitive species (“survival of the fittest”).

A  Pre-adaptation occurs when features are reverses, such as losing eye-sight in sub-terranean species.

B  An adaptation that provides a specific advantage (e.f. wings are used for flying), but serves secondary functions in different circumstances (e.g. wings used for swimming, in aquatic birds).

C  Pre-adaptation is the development of features in anticipation of environmental change (e.g. developing wings when a continent starts subsiding into the ocean).

A  Because the community (“kin”) carries the same genes, and altruism increases chances of survival of the community (“kin selection”).

B  Altruistic behavior is only selected for by evolution if it limits the survival of the altruistic individual.

C  Altruistic behavior is an anomaly and not selected for by evolution.

A  Genetic drift is the deterioration of genes leading to inhertiable disease.

B  Genetic drift is a random fluctuation of genotype frequencies by a chance event.

C  Genetic drift describes the speciation due to continental drift (tectonic plates).

A  This pattern reveals genetic drift

B  The genotype that is increasing in frequency most likely increases the fitness of the individuals who carry it.

C  This pattern reveals a mass extinction event.

A  The combination of survival and reproduction affects gene frequency in subsequent generations, which is one way to quantify fitness.

B  Synonymous (silent) changes in DNA codons.

C  Continental drift drives population change and is therefore a function of fitness.

A  By catching practially all fish above legal size, the fishery creates artificial selection for slower growth because smaller fish survive longer.

B  The fishery increases mortality on the fish population so weak and sick fish are weeded out, so the fish population becomes healthier than desireable.

C  By catching more fish that legally allowed, only the bigger fish can survive and reproduce less often.

A  Individuals within a population that have advantageous features can survive longer than others that don’t have such features, and having advantageous features increases the chances of procreating their kind.

B  Natural selection works towards the goal of achieving a design residing in the genes, i.e. the DNA of bacteria already contained the designs of humans (and even species of the future).

C  Natural selection is the phenomenon of animals selecting their ecological niche during the juvenile phase of their lifespan.

A  Adaptation is when an animal anticipates a change in the environment and prepares by changing its physiology or anatomy (for example Giraffes developing longer necks).

B  Adaptation is the result of repeated practice to improve skills or physiological abilities of a number of individuals over their adult lifetime, and then passing these improvements on to the next generation.

C  Adaptation works in combination with natural selection, as advantageous features of some organisms within a population are preserved through generations.