Question 1

Biodiversity is determined by the number of ______ in an area.

Accepted Answer

Biodiversity is primarily determined by the number of different species in an area, reflecting the variety of organisms present.

Question 2

Where are species placed in the hierarchy of biological organization?

Accepted Answer

The answer of Where are species placed in the hierarchy...

Question 3

A species is defined as one that

Accepted Answer

A species is defined by its ability to reproduce and create viable offspring, distinguishing it from other species through reproductive isolation. This is a fundamental concept in biology for defining species boundaries.

Question 4

Currently, scientists estimate there are approximately ______ known species on the planet.

Accepted Answer

Scientists estimate there are approximately 2 million known species on the planet, though the total number of species, including those not yet discovered, is believed to be much higher.

Question 5

Of the total number of identified species, approximately how many of these are plants?

Accepted Answer

There are approximately 391,000 species of plants known to science, reflecting the vast diversity of plant life on Earth.

Question 6

New species form over time in response to

Accepted Answer

The answer of New species form over time in response...

Question 7

Major extinction events occur

Accepted Answer

Major extinction events are typically associated with punctuated events, such as asteroid impacts or massive volcanic eruptions, which cause rapid and significant changes to the environment.

Question 8

Charles Darwin observed multiple species of finch on the Galápagos islands. He proposed they adapted over time to different habitats of the islands. This is an example of the ______ model of speciation.

Accepted Answer

The gradualistic model of speciation, also known as phyletic gradualism, suggests that species evolve through a gradual process of small genetic changes. Darwin's observation of finches adapting over time to different habitats on the Galápagos Islands is a classic example of this model, where small, incremental changes lead to speciation.

Question 9

The ______ model of speciation results in rapid speciation with a period of no change being interruption by events.

Accepted Answer

The punctuated equilibrium model of speciation suggests that species are generally stable, showing little evolutionary change for most of their geological history. When speciation occurs, it is typically rapid, happening in brief periods of evolutionary time, interspersed with long periods of stasis.

Question 10

Charles Darwin stated that species of finch evolved due to their different locations on the Galápagos islands. This is a type of ______ speciation.

Accepted Answer

Allopatric speciation occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. Charles Darwin's observation of finch species evolving due to their different locations on the Galápagos Islands is a classic example of allopatric speciation, where geographical isolation leads to the development of distinct species.

Question 11

If two plants mate to produce a hybrid, and the hybrid is able to reproduce between other hybrids, this will result in a new species. This is an example of ______ speciation.

Accepted Answer

Sympatric speciation occurs when a new species evolves from a single ancestral species while inhabiting the same geographic region. In this case, the hybridization between two plants in the same area leading to a new, reproductively viable species is an example of sympatric speciation.

Question 12

There are two basic categories that prevent reproduction and therefore prevent speciation. If hybrid offspring survives but is sterile this is an example of

Accepted Answer

Postzygotic isolation occurs after fertilization has taken place, leading to the production of offspring that are often sterile or have reduced fitness, thus preventing further reproduction and speciation.

Question 13

Which extinction period results in the evolution of the first mammals and dinosaurs appearing and forests of conifers and cycades dominate the land?

Accepted Answer

The end-Permian extinction, which saw about 83% of all species on land and sea die, led to the conditions that allowed for the evolution of the first mammals and dinosaurs, and the dominance of conifers and cycads on land. This event dramatically reshaped Earth's biodiversity and ecosystems, paving the way for new forms of life to emerge and dominate.

Question 14

Which statement best describes the number of evolutionary events?

Accepted Answer

There have been five major extinction events in Earth's history, known as the "Big Five," and many scientists argue that a sixth mass extinction is currently underway due to human activities.

Question 15

Phylogenetic trees relate organisms

Accepted Answer

Phylogenetic trees are tools used to depict the evolutionary relationships among organisms, and these relationships can be inferred through various means including the examination of homologous structures, analysis of genetic information such as ribosomal RNA, and other molecular and morphological data. Thus, all the provided options are correct ways in which phylogenetic trees can relate organisms.

Question 16

Which of the two domains are mostly closely related to one another?

Accepted Answer

Archaea and Eukarya are more closely related to each other than either is to Bacteria. This is based on genetic evidence, particularly the sequences of ribosomal RNA genes, which show that Archaea and Eukarya share a more recent common ancestor with each other than with Bacteria.

Question 17

A split between organisms in a phylogenetic tree is represented by a

Accepted Answer

The answer of A split between organisms in a phylogenetic...

Question 18

Mass extinction accounts for almost ______ of species that have gone extinct. This is much greater than background extinction.

Accepted Answer

Mass extinctions are responsible for approximately 85% of species extinctions, significantly more than the rate of background extinction.

Question 19

What caused the Permian mass extinction, which resulted in a 95% extinction rate?

Accepted Answer

The Permian mass extinction is primarily attributed to massive volcanic activity in the Siberian Traps, which led to severe environmental changes, including global warming and ocean acidification.

Question 20

We are currently in the 6th mass extinction. What is causing this extinction?

Accepted Answer

The current, 6th mass extinction is primarily attributed to human activities, including habitat destruction, pollution, overfishing, and climate change, rather than natural events like volcanic activity, asteroid, or comet impacts.

Quiz 9: Annelids, Nematoda, Echinoderms, Primates, Biodiversity, and Speciation