Question 1

How are prokaryotes different from eukaryotes?

Accepted Answer

Prokaryotes lack a nucleus which means their genetic material is not enclosed in a membrane-bound nucleus like in eukaryotes. Prokaryotes have their DNA located in the cytoplasm instead. 
Option A is incorrect as all living organisms have DNA - it is the genetic material that controls the characteristics of living things.
Option C is incorrect as some eukaryotes are unicellular, such as protozoans (unicellular protists), and some prokaryotes are multicellular, such as cyanobacteria.
Option D is incorrect as both prokaryotes and eukaryotes can cause diseases, but prokaryotes are typically associated with more diseases as a group.

Question 2

Algae are classified as part of which group?

Accepted Answer

Algae are classified as part of the Protista kingdom. They are a diverse group of organisms that do not fit into the categories of plants, fungi, or animals. Algae can range from single-celled organisms to complex, multicellular forms and are found in a variety of environments including freshwater and marine habitats.

Question 3

In what way are fungi similar to animals?

Accepted Answer

Fungi and animals are similar in that they both take in food from the outside. Fungi secrete digestive enzymes to break down organic matter externally before absorbing it. This is similar to how animals ingest food and then digest it internally. The other options are not accurate - not all fungi produce hair-like hyphae, they do not form embryos in reproduction, and not all fungi produce antibiotics (while some animals, such as certain species of ants, do produce antibiotics).

Question 4

Which group underwent a large increase in diversity during the Cambrian explosion?

Accepted Answer

The Cambrian explosion was a period of rapid diversification of animal life around 540 million years ago, during which many new phyla (major groups of animals) appeared in the fossil record. Plants, fungi, and bacteria did not undergo significant diversification during this time.

Question 5

Plants possess many compounds that affect animals. What explains these plant characteristics?

Accepted Answer

Plants evolved to produce chemical defenses as a survival strategy against herbivorous animals. Over time, this has resulted in the development of many compounds that affect animals in various ways.

Question 6

Which categories are in the correct order, from most inclusive to least inclusive?

Accepted Answer

Domain is the broadest and most inclusive category, followed by kingdom, phylum, and species as the least inclusive category.

Question 7

Why might archaea be more difficult to grow in the lab than bacteria?

Accepted Answer

Archaea have been found to grow in a variety of extreme environments, including high temperatures, high salinity, and acidic or alkaline conditions. These environments are difficult to recreate in a lab setting, making it challenging to grow archaea in the lab.

Question 8

The evolution of which trait allowed plants to grow taller?

Accepted Answer

Vascular tissue is responsible for transporting water and nutrients throughout the plant, allowing it to grow taller. Seeds, flowers, and photosynthesis are important adaptations, but did not directly contribute to plants' ability to grow tall.

Question 9

You work for a firm that has hired you to look for drugs that work in a similar way to aspirin. Which kingdom of organisms should be included in your first search?

Accepted Answer

Aspirin is derived from a compound found in plants called salicylic acid, which is produced by many species in the Plantae kingdom. Therefore, the first search for drugs that work in a similar way to aspirin should include plants.

Question 10

Why will the leftovers in your refrigerator be guaranteed to eventually grow mold?

Accepted Answer

Fungi are widespread and reproduce quickly, which means that they are commonly present in the environment and will start to grow on organic material (like leftover food) if conditions are favorable. Mold growth is a natural process of decomposition that occurs over time as the fungi break down and consume the organic matter.

Question 11

What is the most important role of bacteria in the environment?

Accepted Answer

The most important role of bacteria in the environment is as decomposers. Bacteria play a crucial role in breaking down dead organic matter and recycling nutrients back into the ecosystem. Without bacterial decomposition, organic matter would accumulate and the nutrient cycling necessary for the survival of other organisms would be disrupted. Bacteria can also play a role in nutrient fixation and cycling in the soil, further supporting plant growth and ecosystem health.

Question 12

What significant event occurred during the Cambrian explosion in Earth's history?

Accepted Answer

The Cambrian Explosion is the period in Earth's history when there was a rapid diversification and emergence of various multicellular animals, including many of the modern phyla. This marks the first appearance of complex animal life on Earth, making option D the correct answer.

Question 13

How could a molecule from plants that blocks the connection between nerves and muscles be useful as a pharmaceutical?

Accepted Answer

A molecule from plants that blocks the connection between nerves and muscles could be useful as a muscle relaxant. This type of pharmaceutical would be particularly useful in surgeries or medical procedures where the relaxation of specific muscles is necessary.

Question 14

What is the adaptive value of natural antibiotic production for fungi?

Accepted Answer

Bacteria are major competitors with fungi for food in the same ecological niche. Therefore, producing natural antibiotics helps fungi to inhibit the growth and restrict the propagation of these bacterial competitors, ultimately improving their own fitness and survival in their environment.

Question 15

Approximately how old is life on Earth?

Accepted Answer

The oldest known fossils are about 3.5 billion years old, and scientific studies suggest that life on Earth may have developed as early as 4.1 billion years ago. Therefore, choice B is the correct answer. Choice A is too large a number, and choices C and D are far too recent for the age of life on Earth.

Question 16

In order to construct an evolutionary classification of modern-day aquatic vertebrates, what is the best source of information?

Accepted Answer

DNA sequence provides the most accurate and detailed information about the evolutionary relationships of modern-day aquatic vertebrates. The analysis of DNA sequences allows for the identification of shared ancestry and evolutionary divergence at the molecular level. This approach allows for a more objective and reliable classification of organisms, rather than relying on superficial features such as organ structure or the distribution of scales.

Question 17

How do fungi obtain nutrients?

Accepted Answer

Fungi are heterotrophs, which means they cannot make their own food unlike plants which perform photosynthesis. Instead, fungi secrete enzymes that break down organic matter (dead plants, animals, or other fungi) and then absorb the resulting nutrients. This process is called external digestion.

Question 18

An organism is described that can live in very high temperature water. What group would contain this organism?

Accepted Answer

Archaea domain contains extremophiles such as thermophiles that can thrive in high temperature environments.

Question 19

To which group are organisms in kingdom Fungi most closely related?

Accepted Answer

Fungi and animals share many characteristics and are thought to have a common ancestor. Both groups are heterotrophic and have similar molecular and cellular features, such as chitin in cell walls and glycogen as a storage compound.

Question 20

What is the result of adaptive radiation?

Accepted Answer

Adaptive radiation is the process by which a single species or small group of species evolve over a relatively short time period into a wide array of descendants that differ in traits and ecological roles. This process leads to the diversification of a few species into a varied group of descendants. It does not necessarily result in the extinction of one species and its replacement with another, nor does it always involve symbiosis or convergent evolution.

Quiz 13: The Greatest Species on Earth Biodiversity and Classification