Exam 4: Evolution, Bacteria, Protista, and Animalia

Question 1

What is the definition of evolution? Why does evolution not occur at an individual level?

Answer 1

The change in the characteristics of a species over several generations relies on the process of natural selection.
Because individuals in a population vary, some can better survive and reproduce given a particular set of environmental conditions.

Question 2

What are the three random mechanisms of evolution?

Answer 2

Mutation, genetic drift, and migration.

Question 3

What is the one non-random mechanism of evolution? What are its requirements?

Answer 3

In non-random mating, organisms may prefer to mate with others of the same or different genotypes.

Question 4

How do stabilizing, directional, and disruptive selection differ?

Answer 4

1) Stabilizing selection reduces the amount of variation in a trait.
2) Directional selection is a form of natural selection where a single trait is selected, which causes the selection of traits only in a specific direction.
3) Disruptive selection increases the amount of variation in traits.

Question 5

What is artificial selection? How is it similar to natural selection? How is it different?

Answer 5

Artificial selection is distinct from natural selection in that it describes selection applied by humans to produce genetic change. When artificial selection is imposed, the trait or traits being selected are known, whereas, with natural selection, they have to be inferred.

Question 6

What is sexual selection?

Answer 6

The process by which individuals compete for access to mates and fertilization opportunities

Question 7

Compare/contrast microevolution and macroevolution.

Answer 7

Microevolution refers to small changes over short periods within a population. Macroevolution refers to more significant changes over a much longer time scale.

Question 8

What are microbes?

Answer 8

Organisms that are too small to be seen without using a microscope

Question 9

What are prokaryotes?

Answer 9

Any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes.

Question 10

Are all microbes prokaryotes? Are all microbes genetically similar?

Answer 10

No, not all microbes are prokaryotes, and all are not microbes. Microbe is vague because commonly described as a living organism

Question 11

How do bacteria and archaea differ? How are they similar?

Answer 11

Archaea do not have interior membranes but have a cell wall and use flagella for swimming. Archaea differ because their cell wall does not contain peptidoglycan, and the cell membrane uses ether-linked lipids instead of ester-linked lipids in bacteria.

Question 12

What are the three primary prokaryote cell shapes?

Answer 12

Prokaryotic cells are typically shaped as either spheres (called cocci), rods (called bacilli), or spirals.

Question 13

How do heterotrophs differ from autotrophs? Do all microbes have similar metabolic processes?

Answer 13

Autotrophs are known as producers because they can make their food from raw materials and energy. Heterotrophs are known as consumers because they consume producers or other consumers. Microbes use many different metabolic strategies, and species can often be differentiated based on metabolic characteristics.

Question 14

What are some examples of adverse microbial effects on humans? What are some examples of positive microbial effects on humans?

Question 15

How do domains, kingdoms, and phyla relate to each other?

Answer 15

A domain is a larger, more inclusive category than a kingdom.
Kingdoms are divided into smaller groups called phyla. They all share higher taxonomic ranking levels of species. In addition, they group living organisms according to evolutionary relationships.

Question 16

What are eukaryotes? Are all eukaryotic organisms similar?

Answer 16

Organisms whose cells contain a nucleus and other membrane-bound organelles. All prokaryotic and eukaryotic cells have similar features as they contain ribosomes, genetic material, a cytoplasm, and plasma membranes.

Question 17

What are protistans? How are they classified (what are their major groups)?

Answer 17

Protists are diverse organisms that do not fit into animal, plant, bacteria, or fungi groups. These are domain, kingdom, phylum (plural, phyla), class, order, family, genus (plural, genera), and species.

Question 18

What are plants? How are they classified (what are their significant groups)?

Answer 18

There are many ways to structure plant classification, and one way is to group them into vascular and non-vascular plants, seed-bearing and spore-bearing, and angiosperms and gymnosperms. Plants can also be grasses, herbaceous plants, woody shrubs, and trees.

Question 19

What are some challenges plants face leaving water to colonize land?

Answer 19

Water loss was the primary challenge plants faced when moving from aquatic to terrestrial environments; cutin, stomata, roots, and root hairs all help terrestrial plants absorb and conserve water.

Question 20

What are the four major evolutionary adaptations plants made to dominate land?

Answer 20

Four major adaptations are found in all terrestrial plants: the alternation of generations, a sporangium in which the spores are formed, a gametangium that produces haploid cells, and apical meristem tissue in roots and shoots

Question 21

What is meant by the alternation of generations? How do sporophyte and gametophyte
generations differ? What is a dominant generation?

Answer 21

Alternation of generations means that plants alternate between two different life stages, or generations, in their life cycle. The asexual phase represents the sporophyte generation, while the sexual phase represents the gametophyte generation. The dominant generation is diploid, and the sporophyte comprises the main plant

Question 22

Draw and label a flower, indicating all male and female structures. What is the purpose of
flowers? Fruit? Seeds? Spores?

Answer 22

To reproduce or to make more of themselves. They do so by making seeds or spores. Seeds and spores contain the genetic material needed to grow a new plant. Under the right conditions, seeds and spores will germinate or grow into plants.

Question 23

What are fungi? What are their main distinguishing characteristics?

Answer 23

A plant-like organism that does not make chlorophyll. Mushrooms, yeasts, and molds are examples. Fungi are eukaryotic, non-vascular, non-motile, and heterotrophic organisms. They may be unicellular or filamentous. They reproduce utilizing spores. Fungi exhibit the phenomenon of alternation of generation.

Question 24

What are lichen and mycorrhizae? What benefits do they provide their symbiote partners?

Answer 24

A mycorrhiza is a symbiotic relationship between the roots of a plant and a fungus, while lichen associates between a fungus and an algae. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities, while the plant provides the fungus with carbohydrates formed from photosynthesis.

Question 25

How are animals distinguished from other members of Eukarya?

Answer 25

Animals are unique amongst eukaryotic organisms because animal tissues are bound together by a protein called collagen

Question 26

Identify the nine major animal phyla discussed in class, listing at least one distinguishing
feature (something only found in this phyla) for each.

Answer 26

Porifera, cnidaria, platyhelminthe, nematoda, annelida, arthropoda, mollusca, echinodermata, and chordata.

Question 27

What is meant by protostome vs. deuterostome development? What is a coelom? How to
do digestive systems differ from tube digestive systems?

Answer 27

The critical between protostomes and deuterostomes is the fate of the blastopore during their embryonic development. The fluid-filled body cavity of an animal contains the internal organs (such as the heart, lungs, and kidneys). The digestive system comprises the digestive tract and other organs that help the body break down and absorb food.

Question 28

What are tetrapods? What is an amniotic egg, and why is it considered an evolutionary
advancement?

Answer 28

A group of vertebrates includes amphibians, reptiles, birds, and mammals. Amniotic eggs are found in amniotes, which either lay them in the terrestrial environment or retain the egg with the body. It is considered an important evolutionary innovation as it prevents fertilization outside the female body and increases survival.

Question 29

Are all chordates vertebrates? Do all mammals have placentas?

Answer 29

In vertebrates, the notochord is replaced by the vertebral column (backbone). However vertebral column is not present in a protochordate. Therefore, all vertebrates are chordates, but all chordates are not vertebrates. All mammals except the egg-laying platypus and the five species of echidnas, the only surviving monotremes, rely on a placenta for their reproduction