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What are the key elements of the environment?


Study of how organisms relate to one another and to their environments.


Individuals must maintain a steady-state internal environment regardless of external environment.

Physiological responses
Morphological capabilities
Behavioral responses

What are the coping mechanisms of environmental challenges?

Physiological responses

What type of coping mechanism involves sweating, increased erythrocyte production, and making "antifreeze"

Morphological capabilities

What type of coping mechanism involves endotherms have adaptations that minimize energy expenditure, for example, thick fur coats during the winter.

Behavioral responses

What type of coping mechanism involves moving from one habitat to another and maintaining body temperature?


Groups of individuals of the same species in one place.

Population range
Pattern of spacing of individuals
How population changes in size through time

What are the 3 characteristics of population ecology?


Quantitative study of populations

generation times

Average interval between birth of an individual and birth of its offspring.


Group of individuals of the same age.


Number of offspring produced in a standard time.


death rate in a standard time


percent of an original population that survives to a given age

survivorship curve

express some aspects of age distribution

life history

complete life cycle of an organism


limited resources vs. increased reproduction


what are the factors that affect exponential growth?

sigmoidal growth curve

N vs t plotted


factors that affect the population and depend on population size.


other factors, such as natural disasters, affect population regardless of size.

K-selected populations

Adapted to thrive when population is near it carrying capacity.

r-selected populations

Selection favors individuals with the highest reproductive rates.

Ecological Footprint

amount of productive land required to support an individual at the standard of living of a particular population through the course of his/her life.


species that occur at any particular locality

species richness

number of species present

primary productivity

amount of energy produced


places where the environment changes abruptly

ecological niche

The total of all the ways an organism uses the resources of its environment

interspecific competition

Occurs when two species attempt to use the same resource and there is not enough resource to satisfy both

interference competition

Physical interactions over access to resources.

Exploitative competition

Consuming the same resources.

fundamental niche

Entire niche that a species is capable of using, based on physiological tolerance limits and resource needs

realized niche

Actual set of environmental conditions, presence or absence of other species, in which the species can establish a stable population

principle of competitive exclusion

If two species are competing for a limited resources, the species that uses the resource more efficiently will eventually eliminate the other locally


consuming of one organism by another

defensive coloration

Insects and other animals that are poisonous use warning coloration

Batesian mimicry

mimics look like distasteful species

Mullerian mimicry

Several unrelated but poisonous species come to resemble one another


2 or more kinds of organisms interact in more-or-less permanent relationships


What are the 3 major types of symbiosis?


Benefits one species and is neutral tot he other

Spanish moss and an epiphyte hangs from trees

What is an example of commensalism?


Benefits both species

Ant: provide protection from herbivores
Acacias: provide hollow thorns and food

What is an example of mutualism?


Benefits one species at the expense of another


feed on exterior surface of an organism


Insects lay eggs on living hosts


Communities have a tendency to change from simple to complex

Primary succession

Occurs on bare, lifeless substrate

Secondary succession

Occurs in areas where an existing community has been disturbed but organisms still remain


Early successional species are characterized by r-selected species tolerant of harsh conditions


Early successional species introduce local changes in the habitat. K-selected species replace r-selected species


Changes in the habitat caused by one species inhibits the growth of the original species

Intermediate disturbance hypothesis

Communities experiencing moderate amounts of disturbance will have higher levels of species richness than communities experiencing either little or great amounts of disturbance


The rate at which the organisms in the trophic level collectively synthesize new organic matter.

Primary productivity

productivity of the primary producers


Rate at which primary producers break down organic compounds.

Gross primary productivity

Raw rate at which primary producers synthesize new organic matter

Net primary productivity

The gross primary productivity less the respiration of the primary producers

Secondary productivity

Productivity of a heterotroph trophic level

ecological pyramids

pyramid of energy flow or pyramid of productivity

trophic cascade

process by which effects exerted at an upper level flow down to influence two or more lower levels

top-down effects

When effects flow down.

Bottom-up effects

When effects flow up through a trophic chain


___ is(are) the genetic material for all cellular organisms and some viruses.


Nucleotides have phosphates attached at the ___ carbon atom of the sugar.

double helix

Watson and Crick developed a model of DNA in which the two strands twist into the shape of a ________________.


Since both the strands of a DNA molecule are complimentary to each other, either one of the strands can be used as a _______ to reconstruct the other.


The synthesis of the growing chain of DNA is carried out by adding nucleotides to the ________ end.

hydrogen bonds

DNA consists of two antiparallel strands of nucleotide chains held together by

semiconservative method

The method of DNA replication, where each original strand is used as a template to build a new strand, is called the

5' end

The reading of the bases along the length of a nucleic acid molecule for either transcription or translation is done from the

phosphodiester bond

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

hydrogen bonds

The chemical bonds that stabilize the complimentary nitrogen bases into a double helix are


The two strands in the DNA molecule contain nitrogen bases which are


The essence of heredity is the ability of cells to use the information in their DNA to bring about the production of particular _______, thereby affecting the function of the cells.


The expression of a gene involves two phases, ___________ and translation.


In ________, a ribosome assembles a polypeptide, whose amino acid sequence is specified by the nucleotide sequence in the mRNA (which itself is a copy of the template DNA).


The coded order of nucleotides in DNA specifies the order of specific amino acids to be assembled into a polypeptide chain. This code is therefore called the ________ code.


Both DNA and RNA are made up of building blocks known as


The nucleotide sequence of an mRNA codon is composed of how many bases?

production of many varieties of polypeptides and proteins.

The many different functions and behaviors of living organisms are essentially based on the performance of their cells. The cells' performance in turn is dependent upon the


Protein synthesis takes place on

the first nucleotide in every codon is always the same

The genetic code operates on all the following except

-all four of the nucleotide bases must be used.
-each combination of any three nucleotides can act as a codon.
-the first nucleotide in every codon is always the same.
-a particular codon always specifies the same amino acid.

an anticodon

The tRNA nucleotide sequence that lines up on the mRNA is

peptide bond

The bond that forms between the newly added amino acid and the previous amino acid on the chain is called a


The location of protein synthesis in eukaryotic cells is the

DNA→ RNA→ proteins.

The Central dogma of biology is stated as

Retroviruses have a RNA genome rather than a DNA genome. These viruses convert their RNA genome into DNA for the purpose of replication. Following genome replication, the DNA is transcribed back into RNA and then translated into protein. The conversion of RNA → DNA violates the information flow of the central dogma, which states DNA → RNA →protein.

How do retroviruses, such as the Human Immunodeficiency Virus (HIV), violate the central dogma of molecular biology?


The key point in Darwin's proposal is that the ___________ imposes the conditions that determine the direction of selection.


Selection cannot alter a trait with little or no genetic variation and will not eliminate _________ alleles.


Natural selection, as a mechanism of evolution that, acts on variants within populations and ultimately leads to the evolution of different species was proposed by


Features that increase the likelihood of survival and reproduction by an organism in a particular environment are called

all of the alleles of genes within a population

The gene pool includes

bottleneck effect

A restriction in genetic variability caused by a drastic reduction in population size is called a


The genetic contribution of an individual to succeeding generations, compared with that of other individuals in the population, is known as


The frequency of a particular allele within a population can be changed, over time, by

assortative mating

The type of non-random mating that causes the frequencies of particular genotypes to differ greatly from those predicted by the Hardy-Weinberg equilibrium is called

hybridization between individuals and adjacent populations

Gene flow, defined as the movement of genes from one population to another, can take place by migration, as well as

random mating

Which one of the following is not an agent of evolutionary change

gene flow
random mating
genetic drift

directional selection

When selection acts to eliminate one extreme from an array of phenotypes it is called

there is very little genetic variability

Cheetahs have been through a genetic bottleneck; evidence for this is that

heterozygote advantage

The text discusses sickle-cell anemia, which is a classic example of

Phenotypic variation of a species has variable appeal to humans interested in that species.

Which of the following is not important to the concept of natural selection, but does factor into artificial selection?

-Most organisms are capable of producing more offspring than typically survive.
-Phenotypic variation of a species has variable appeal to humans interested in that species.
-Phenotypic variation exists within populations.
-Phenotypic variation can influence reproductive success.
-Phenotypic variation within a species is due in part to inherited characteristics.

the available food supply.

Darwin's finches have adapted to feed in different ways in response to:

radioactive isotope decay

A technique used in dating a rock can be used to accurately predict the age of the fossils occurring in the rocks. This technique involves

analogous structures

Evidence for evolution can be obtained by examining presently existing species through studies on each of the following except one. Select the exception.

early development
vestigial structures
patterns of distribution
analogous structures

homologous structures

Structures that are derived from the same body part in a common ancestor but may have different appearances and functions are called

vestigial structures

Many organisms possess structures that have no apparent function, but they resemble structures of presumed ancestors. This is the study of


During growth in the mother's uterus, human embryos and fetuses exhibit characteristics of other vertebrates, suggesting that humans are related to the other forms. This represents which of the following lines of evolutionary evidence?

must be found in the same biogeographical region

Which one of the following is not true about species that show convergent evolution?

-Do not share a recent common ancestor.
-Must be found in the same biogeographical region.
-Subject to similar selection pressures.
-Have similar phenotypes.
-Can share homologous structures.

intelligent design

Evidence for evolution includes all of the following except

-the fossil record.
-homologous structures.
-the molecular record.
-intelligent design.
-vestigial structures.


A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called a _____________ isolating mechanism.


Two groups of organisms that are unable to form fertile, viable hybrids are considered to be different

hybrid sterility

All of the following are examples of prezygotic isolating mechanisms except

-ecological isolation.
-temporal isolation.
-mechanical incompatibility.
-hybrid sterility.
-prevention of gamete fusion.

hybrid zygotes

Prezygotic mechanisms lead to reproductive isolation by preventing the formation of


Most eukaryotic cells go through a repeating process of growth and division referred to as the cell _____.


The accommodation of the very long DNA fiber into a limited space of the nucleus is achieved by coiling around beads of histones into repeating subunits. These subunits of chromosomes are given the name _________.


Prophase is the first stage of mitosis characterized by the ______ of the chromosomes


__________ is the stage of mitosis characterized by the alignment of the chromosomes in a circle at the center of the cell.


The stage of mitosis characterized by the physical separation of sister chromatids is called _________.


The last stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decondensation of the chromosomes into invisible threads. This stage is known as ________.


The progress of mitosis is regulated by ______ and their dependent kinases.


If a eukaryotic cell has a single set of chromosomes, it is called


The physical distribution of cytoplasmic material into the two daughter cells is called


In the human, the body cell (non-sex cells) contain two sets of chromosomes totaling.

sister chromatids

Before cell division of somatic cells, each homologue replicates into two parts. These parts are connected by a centromere and are called

G1 to S to G2 to M to C

Which sequence below is characteristic of eukaryotic cell cycle?


The attachment of which molecules is critical for the proper separation of sister chromatids?

forming a cell plate across the middle of the cell

Plant cells typically achieve cytokinesis by


Which of the following is not a checkpoint for cell cycle control in a eukaryotic cell?


binary fission

The actual process of cell division in prokaryotic cells is called


If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes?


Hereditary information is partitioned equally between two daughter cells during


______ cells such as gametes contain one set of chromosomes.


The two homologous chromosomes pair along their length early in the first nuclear division. During this physical joining genetic exchange occurs between them in a process called ________.


Sexual reproduction is significant in increasing genetic _____.


Diploid organisms use meiosis for the development of gametes. Meiosis consists of how many rounds of nuclear division?


The pairing of chromosomes along their lengths which is essential for crossing over is referred to as.


The reduction division that separates two haploid complements from each other is called


All of the following animal cells are diploid except

-reproductive organ.

homologous pairs of chromosomes pair up along their length.

In one of the first steps in meiosis, the

crossing over

Chromosomes exchange genetic information by

prophase I

Crossing over of the chromosomes takes place in


Sexual reproduction increases genetic variability through all of the following except

-crossing over in prophase I of meiosis.
-independent assortment in meiosis.

Mitosis is nuclear division, which ultimately leads to diploid somatic cells. Meiosis is nuclear division, which ultimately leads to haploid gametes.

Meiosis and mitosis are both processes that involve nuclear division. What is the difference between the two?


After fertilization, the resulting zygote develops by which of the following processes?

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