Test One Semester Two

Question 1

struggle for existence

Answer 1

o Certain factors limit the size a population of organisms. Many of these factors are correlated to overpopulation. Examples of this include disease, competition, and predation.
o Because there are limited resources, organisms in a population must compete to obtain these limited resources. Organisms with good traits are able to out-survive organisms with lesser traits, and survive to reproduce.

Question 2

variation

Answer 2

o Necessary for natural selection and evolution to occur.
o In a population, there are multiple forms or phenotypes for a given trait. Because there are multiple forms of a trait, some traits are more successful than others. Individuals with successful variations are able to survive and reproduce, passing on their successful traits to their offspring.

Question 3

artificial selection

Answer 3

o When humans selectively breed organisms in attempt to create desired phenotypes in offspring.
o Nature provides the variation, and humans select for the traits which they want to occur in the offspring.

Question 4

biogeography

Answer 4

o Study of the past and present distribution of organisms

o Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors

Question 5

Hutton

Answer 5

o Hutton recognized the connections between geologic processes and geologic features like mountains, valleys, or layers of rock that appear to be folded
o Introduced a concept called deep time that our planet’s history stretches back over a very long period of time

Question 6

Lyell

Answer 6

o Argued that the laws of nature are constant over time and that processes that occurred in the past can be explained by events that occur in the present

Question 7

Malthus

Answer 7

o Realized that if the human population grew unchecked, there wouldn’t be enough food, living space, or other resources to go around

Question 8

divergent evolution

Answer 8

o This type of evolution begins with a common ancestor. Organisms evolve characteristics all based on the same ancestor, but they adapt traits into different forms or variations

Question 9

homologous structures

Answer 9

structures that are similar in different species of common ancestry (through divergent evolution)

Question 10

convergent evolution

Answer 10

o Process by which unrelated organisms independently evolve similarities when adapting to similar environments.

Question 11

analogous structures

Answer 11

body parts that share a common function, but don’t share a common structure (because they were derived through convergent evolution)

Question 12

comparative embryology

Answer 12

o Similar patterns of embryological development provide further evidence that organisms have descended from a common ancestor

Question 13

molecular evidence/modern synthesis

Answer 13

o At the molecular level, the universal genetic code and homologous molecules provide evidence of common descent

Question 14

comparative anatomy

Answer 14

o Organisms that have similar anatomy may reflect a shared common evolutionary history

Question 15

vestigial characteristic

Answer 15

o reflect divergent evolution and a common evolutionary past, but they have lost their function in the modern organism. The traits just haven’t been lost because there have been no pressures for this to occur.

Question 16

natural selection

Answer 16

• Variation within population
• Species with high reproductive capacity
• Differential survival and differential reproductive success
• Survivors’ characteristics inherited by offspring leads to a gradual accumulation of favorable characteristics

Question 17

evolutionary biology (modern synthesis)

Answer 17

• Genes are a source of variation
• Comparative anatomy
• Fossil record
• Biogeography
• Molecular biology
• Comparative embryology

Question 18

speciation

Answer 18

the formation of new species

Question 19

how does speciation occur?

Answer 19

• For one species to evolve into two new species, the gene pools of two populations must become separated, or reproductively isolated.
• Reproductive isolation occurs when members of two populations do not interbreed and produce fertile offspring.
• Reproductive isolation can develop through behavioral, geographic, or temporal isolation:

Question 20

taxonomy

Answer 20

the science of classifying and naming organisms. Sometimes referred to as systematics.

Question 21

Carl von Linnaeus

Answer 21

• Proposed the Hierarchal System of classification:
o In whichtThere is a broad taxon, and within that taxon, organisms can be divide up into even smaller levels of classification, and continue to subdivide (Domain, kingdom, phylum, class, order…)
• Proposed the Binomial System of Nomenclature:
o Every group of organisms (that are considered members of the same species because they can successfully reproduce and produce fertile offspring together) has a two part name, composed of the genus name followed by the species name.

Question 22

what are the three domains?

Answer 22

Eukarya (cells have a nucleus), Bacteria (prokaryotes that are not related to Eukaryotes), Archaea (prokaryotes that are more closely related to eukaryotes)

Question 23

kingdoms of the domain Eukarya

Answer 23

protists, plants, fungi, animals

Question 24

characteristics to consider when classifying

Answer 24

•	Number of cells
o	single or multicellular
•	Type of cell 
o	prokaryote or Eukaryote
•	How does it obtain energy
o	Producer of consumer
•	Autotroph or heterotroph

Question 25

how are bacteria and archaea similar?

Answer 25

• prokaryotes (no membrane-bound organelles)
• all single celled
• all have a cell wall
• all have one circle shaped chromosome
• very small

Question 26

how are archaea and eukarya similar?

Answer 26

• cell wall construction (no pepdioglycan)

- arrangement of genetic material

Question 27

what do all prokaryotes have?

Answer 27

single cell, cell wall, no nucleus

Question 28

classification of prokaryotes:

Answer 28

How do they obtain energy:
o	Autotrophic or Heterotroph
•	Photoautotrophs, chemoautotrophs
•	Metabolism
o	Aerobe or anaerobe
•	Reproduction
•	Cell wall structure
o	Peptidoglycan
•	Habitat
•	Shape (spherical, rod, spiral)

Question 29

Gram stain

Answer 29

• When trying to distinguish prokaryotes, if a cell has peptidoglycan, it is bacteria, if not, it is Archaea
• Gram Stain:
o Done on bacteria (stains the peptidoglycan)
• Some bacteria will take up the stain and are known as gram positive. Ones that won’t are gram negative. Gram negative means that the bacteria has a more complex structure: the cell wall is sandwiched between an outer membrane and an inner membrane.

Question 30

binary fission

Answer 30

asexual reproduction

1. Cell replicates their DNA (just like in interphase of mitosis)
2. Cells then split (without mutation, variation will not occur)

Question 31

sources of variation for bacteria

Answer 31

• Mutation
• Transformation
o When the cell divides, its plasma gets left in the environment and then other cells pick it up during their divisions
• Transduction
• Conjunction:
o Cells (the pillae), for a cytoplasmic connection
o There are opposite mating strains that recognize each other through molecules on the outside of their cells.

Question 32

domain archaea and kingdom archaebacteria

Answer 32

•	Prokaryote
•	Ancient
•	Classify by habitat
o	Methanogens
o	Thermophiles
o	Halophiles
•	Asexual reproduction
•	DNA similar to Eukarya
•	Cell wall similar to Eukarya (no peptidoglycan)

Question 33

are protists unicellular or multicellular?

Answer 33

most are unicellular, multicellular organisms e.g. some algaes are exceptions

Question 34

types of protists

Answer 34

-Algae= autoptrophic photoautotrophs
• Most algae are unicellular, but seaweed is a multicellular exception
• Algae can be classified by their dominant photopigments (red, brown, green)

-Slime Molds=heterotrophs, but they are all decomposers
• Fungi-like
• Single-celled but often gather together to form very big groups

• Protozoans=heterotrophic, eats other things
• Believed to be the ancestors of animals

Question 35

movement of protozoa

Answer 35

• Sarcodonids
◦ For example, amoeba
◦ Move by cytoplasmic streaming, and they form pseudopods
◦ Endocytosis is their method for taking in food
• Flagellates
◦ Move using flagella (a moveable extension), often one flagella, sometimes multiple
◦ For example, Euglena (euglena is green, because it can photosynthesize, but they can also be heterotrophic)
◦ A lot of flagellates are parasitic: e.g. Giardia (often found in water)
• Ciliates
◦ They have cilia (many small, short hairlike structures on the cell)
◦ Tend to move the fastest
◦ Cilia are shorter than flagella, and there tend to be more of them
• Sporozoans
◦ Don’t move at all
◦ They are parasitic. For example, the parasite that causes malaria

Question 36

how does endosymbiosis relate to protists

Answer 36

Protists are considered to be the earliest Eukaryotes. They would have thus been derived through endosymbiosis.

Question 37

plasmodium

Answer 37

The genus name for the parasite that causes malaria (there are multiple species)
• It is a protozoan (sporozoan)
• Carried by mosquitoes, whom it does not harm
• The parasite eats the contents of red blood cells