Question 1

The existence of evolutionary trends,such as increasing body sizes among various horse species,is evidence that
A)a larger volume-to-surface area ratio is beneficial to all mammals.
B)an unseen guiding force is at work.
C)evolution always tends toward increased complexity or increased size.
D)in particular environments,similar adaptations can be beneficial in more than one species.

Accepted Answer

The existence of evolutionary trends, such as increasing body sizes among various horse species, is evidence that in particular environments, similar adaptations can be beneficial in more than one species. It is not evidence of an unseen guiding force, evolutionary trends do not necessarily always tend towards increased complexity or size, and a larger volume-to-surface area ratio may not be beneficial to all mammals in all environments.

Question 2

Over time,new forms of life have arisen by
A)modification of existing structures or existing developmental genes.
B)sexual selection only.
C)the process of species living in variable environments with the end goal of mutating and evolving.
D)the availability of resources after other species go extinct.

Accepted Answer

New forms of life have arisen through the modification of existing structures or existing developmental genes. This is known as evolutionary adaptation, where organisms adapt to changing environmental conditions over time through genetic changes, such as mutations or gene expression modifications. Sexual selection and the availability of resources after other species go extinct can also play a role, but they are not the primary driving force behind the creation of new forms of life. The idea of a "process of species living in variable environments with the end goal of mutating and evolving" is not entirely accurate, as evolution is not a goal or purposeful process, but rather a result of natural selection acting on genetic variation.

Question 3

Speciation that occurs when continents move and cause geographic barriers to gene flow and reproduction between populations of species would be termed which of the following?
A)allopatric
B)sympatric
C)peripatric

Accepted Answer

The answer of Speciation that occurs when continents move and...

Question 4

An organism has a relatively large number of Hox genes in its genome.Which of the following is true of this organism?
A)These genes are fundamental and are expressed in all cells of the organism.
B)The organism must have multiple paired appendages along the length of its body.
C)The organism has the genetic potential to have a relatively complex anatomy.
D)Most of its Hox genes owe their existence to gene fusion events.

Accepted Answer

Hox genes are responsible for controlling the development of body structures and organs in animals. The presence of a relatively large number of Hox genes in an organism's genome indicates that it has the genetic potential to have a relatively complex anatomy. This is because each Hox gene can control the development of a specific body segment or structure, and having more Hox genes allows for more precise control over the development of these features. However, the number of Hox genes alone does not determine the complexity of an organism's anatomy, as other factors such as environmental pressures and developmental processes also play a role. Option A is false because Hox genes are not expressed in all cells of an organism but are specifically expressed in cells related to body patterning. Option B is false because the presence of multiple paired appendages is not solely determined by the number of Hox genes but also by other genetic and developmental factors. Option D is false because most Hox genes are thought to have arisen through gene duplication events, not gene fusion.

Question 5

The history of continental drift on Earth has
A)allowed for speciation to occur.
B)allowed for both speciation and extinction to occur.
C)caused speciation rates to exceed extinction rates.
D)caused speciation to equal extinction rates.

Accepted Answer

Continental drift has allowed for both speciation, as new environments and geographic barriers have formed, and extinction, as species are separated and cannot compete or adapt. Therefore, both speciation and extinction rates have been influenced by continental drift.

Question 6

Larval flies (maggots)express the Ubx gene in all their segments and thereby lack appendages.If this same gene continued to be expressed throughout subsequent developmental stages,except in the head region,and if the result was a fit,sexually mature organism that still strongly resembled a maggot,this would be an example of
A)exaptation.
B)homochrony.
C)paedomorphosis.
D)adaptive radiation.

Accepted Answer

This scenario describes paedomorphosis, which occurs when an organism retains juvenile features into adulthood. In this case, the continued expression of the Ubx gene would result in an adult fly that still lacks appendages and strongly resembles a maggot (its juvenile form).

Question 7

During the Cambrian explosion,fossil evidence indicates a rapid and sudden diversification of more complex animals.However,fossils of Ediacaran animals from 30 million years prior to this demonstrate that genes to produce complex animals had already existed.What could explain this?
A)a lack of gene expression due to lack of stress on the Cambrian species
B)changes in the environment that brought about selective adaptations and evolution during the Cambrian,repurposing some gene regions through differential regulation
C)changes that led to the innate ability of organisms during the Cambrian to mutate in response to environmental pressures or opportunities
D)a spatial pattern of organisms across the landscape during the Ediacaran that allowed adaptations and evolution

Accepted Answer

It is likely that changes in the environment during the Cambrian period caused selective adaptations and evolution, utilizing some gene regions through differential regulation. This could explain the sudden diversification and complexity of animals during the Cambrian explosion, despite the existence of complex animal genes during the Ediacaran period.

Question 8

What type of genes control how flower petals are arranged or where a set of wings on a bird will develop?
A)homeotic genes
B)paedomorphic genes
C)gene sequences
D)convergent genes

Accepted Answer

Homeotic genes control the development of body plans and the positioning of body parts. They are responsible for determining where and how petals, wings, legs, and other body structures will develop.

Question 9

Learning from the history about plate tectonics on Earth,scientists now predict that
A)continents will continue moving apart for a few hundred million years more.
B)continents may come back together during the next few hundred million years,forming new mountain ranges and larger continents.
C)continents will soon slow in their drift and stabilize.
D)continents will speed up in their drift across the planet,potentially causing a sixth major extinction event.

Accepted Answer

Plate tectonics has shown that continents have moved apart and come back together in the past. Therefore, scientists predict that the same will happen in the future, leading to new mountain ranges and larger continents forming. Continents slowing down or speeding up in their drift is not supported by current evidence. The idea of a sixth major extinction event due to the movement of continents is not a widely accepted theory.

Question 10

Hox genes are a group of related genes that
A)control the body plan of an embryo and are conserved across many taxonomic groups.
B)do not affect change in location.
C)do not affect plant development.
D)control the body plan of an embryo of a small portion of animal species.

Accepted Answer

Hox genes are a group of genes that are highly conserved and control the body plan of an embryo in many different taxonomic groups. They are responsible for determining the placement and identity of body segments during development.

Question 11

Records of extinctions on the planet indicate that
A)although Earth has experienced five mass extinctions,the diversity of life appears to be greater now than ever before.
B)mass extinctions on the planet have caused a steady decline over hundreds of millions of years,both in the numbers and abundance of species.
C)mass extinctions have caused the number of predator genera to decline over time.
D)extinction rates are highest when global temperatures are lower.

Accepted Answer

Mass extinctions, despite their devastating impact, have been followed by periods of recovery and diversification, leading to an increase in the diversity of life over time.

Question 12

Many species of snakes lay eggs.However,in the forests of northern Minnesota where growing seasons are short,only live-bearing snake species are present.This trend toward species that perform live birth in a particular environment is an example of
A)natural selection.
B)sexual selection.
C)species selection.
D)goal direction in evolution.

Accepted Answer

The answer of Many species of snakes lay eggs.However,in the...

Question 13

In the 5 to 7 million years that the hominid lineage has been diverging from its common ancestor with the great apes,dozens of hominid species have arisen,often with several species coexisting in time and space.As recently as 30,000 years ago,Homo sapiens coexisted with Homo neanderthalensis.Both species had large brains and advanced intellects.The fact that these neurological traits were common to both species is most easily explained by which of the following?
A)species selection
B)uniformitarianism
C)sexual selection
D)convergent evolution

Accepted Answer

Species selection explains the presence of similar traits in closely related species due to those traits being selected for across the species' lineage, which fits the scenario of both Homo sapiens and Homo neanderthalensis having large brains and advanced intellects.

Question 14

Exaptations
A)imply that a structure evolves in anticipation of use.
B)evolve in one environment but are used for another function.
C)process new forms by modifying existing forms.
D)trend toward larger body size.

Accepted Answer

Exaptations are evolutionary adaptations that were originally developed for one purpose but have been co-opted for another function. The original function was not necessarily a key factor in the organism’s evolutionary history, but the trait became adapted for a new function that aided its survival.

Question 15

A change in the nucleotide sequence of a gene affects function of that gene
A)in cells that express that gene.
B)but is limited to a single cell type.
C)after gene duplication events.
D)resulting in paedomorphosis.

Accepted Answer

A change in the nucleotide sequence of a gene can affect the function of that gene in the cells that express it. This is because the nucleotide sequence determines the amino acid sequence of the protein that the gene codes for, and changes in the amino acid sequence can alter the protein's structure and function.

Question 16

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene
A)duplication (gain in number).
B)elimination (loss).
C)mutation (change).
D)silencing (loss of expression).

Accepted Answer

The loss of ventral spines in modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of the Pitx1 gene, specifically through the silencing (or loss of expression) of the gene. This has been demonstrated through experiments that have shown that when the Pitx1 gene is silenced in ancestral marine sticklebacks, they develop a stickleback-like body with reduced ventral spines, similar to modern freshwater sticklebacks.

Question 17

What is critical to understand about the following statement? Eyes could not have evolved over time,part by part,because for the eyeball to function at all,it needs all of its parts working together.
A)Many different taxa rely on simple eyes to survive,which function and are missing some components of more complex eyes.
B)An eye can only work to form and image and transmit it to the brain if it has all components.
C)The purpose of an eye is always to form and image and transmit the image to the brain.
D)Eyes that distinguish only light from dark are too simple to be useful.

Accepted Answer

A) Evolutionary biology shows that eyes have evolved in complexity over time, starting from simple light-sensitive cells to the complex structures seen in humans and other animals. Simple eyes, which lack some components of more complex eyes, are still functional and beneficial for survival in many organisms.

Question 18

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate.Adult female bagworm moths are larval in appearance;they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag.This is a good example of
A)allometric growth.
B)paedomorphosis.
C)sympatric speciation.
D)adaptive radiation.

Accepted Answer

The retention of larval features in sexually mature individuals is known as paedomorphosis. In this case, adult female bagworm moths retain their larval appearance, which is an example of paedomorphosis. Allometric growth refers to the differential growth rates of different body parts or structures, and it is not relevant in this context. Sympatric speciation and adaptive radiation are mechanisms of evolution that lead to the divergence of species over time and are not applicable to this scenario.

Question 19

One explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation.When they had become sufficiently large,these extensions became useful for gliding through the air,and selection later refined them as flight-producing wings.If this hypothesis is correct,modern insect wings could best be described as
A)adaptations.
B)mutations.
C)exaptations.
D)isolating mechanisms.

Accepted Answer

According to the hypothesis, modern insect wings evolved as lateral extensions of the body that were initially used for thermoregulation but later refined for flight. This suggests that wings were not originally adapted for flight, but rather co-opted for that purpose, making them exaptations.

Question 20

Adaptive radiation
A)reduces the size of prosperous ecological communities.
B)increases extinction rates.
C)allows new species to occupy different habitats.
D)observes trends in the fossil record.

Accepted Answer

Adaptive radiation is the process in which a single ancestral species evolves into multiple new species, each occupying different ecological niches. This allows for new species to occupy different habitats and diversify the ecological community. It does not necessarily reduce the size of prosperous ecological communities and is not directly related to extinction rates. It can be observed in the fossil record through the appearance of many new species in a relatively short period of time.

Quiz 23: Broad Patterns of Evolution

The existence of evolutionary trends,such as increasing body sizes among various horse species,is evidence that

Over time,new forms of life have arisen by

Speciation that occurs when continents move and cause geographic barriers to gene flow and reproduction between populations of species would be termed which of the following?

An organism has a relatively large number of Hox genes in its genome.Which of the following is true of this organism?

The history of continental drift on Earth has

During the Cambrian explosion,fossil evidence indicates a rapid and sudden diversification of more complex animals.However,fossils of Ediacaran animals from 30 million years prior to this demonstrate that genes to produce complex animals had already existed.What could explain this?

What type of genes control how flower petals are arranged or where a set of wings on a bird will develop?

Learning from the history about plate tectonics on Earth,scientists now predict that

Hox genes are a group of related genes that

Records of extinctions on the planet indicate that

Many species of snakes lay eggs.However,in the forests of northern Minnesota where growing seasons are short,only live-bearing snake species are present.This trend toward species that perform live birth in a particular environment is an example of

Exaptations

A change in the nucleotide sequence of a gene affects function of that gene

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene

What is critical to understand about the following statement? Eyes could not have evolved over time,part by part,because for the eyeball to function at all,it needs all of its parts working together.

Adaptive radiation