165 terms

BIO 151 Exam 4

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?
there is a reduction in the chromosome number during two separate nuclear and cell divisions to produce gametes.
Meiosis also has been called reduction division because
In 95% of cases of Down's syndrome, there is an extra piece of chromosome 21 in every cell. This aneuploid condition is the result of
The phenotypic ratio for a testcross with a homozygous individual and a heterozygous individual is ______.
The ________ of an organism is the physical appearance resulting from the expression of the genes present.
Alternate forms of the same gene are called _____.
The Principle of ________ states that alternative alleles for a trait separate from one another during gamete formation and remain distinct.
recessive gene
A gene for a particular trait that is only expressed in the presence of another gene of the same kind is called a(n)
When the two haploid gametes contain two different alleles of a given gene, the resulting offspring is called
The allelic make up of an individual is referred to as its
all genes found in an individual are not separable into gametes
Mendel's first law encompasses all of the following except

-alternative forms of trait are encoded by alternative alleles.
-alternative alleles segregate in gametes.
-either allele has equal probability to be passed on into the gamete.
-all genes found in an individual are not separable into gametes.
they are on different chromosomes
One of the main reasons genes assort independent of one another is that
multiple alleles
ABO blood group expression is an example of
Many genes, rather than one gene for a characteristic, control some variations in species.
Height and eye colors are two examples of continuous variation in humans. Whereas in pea plants the tall allele is dominant over the short allele, there are no intermediate heights in peas. Which of the following is the best explanation for the differences described above?
A diploid individual carrying two different alleles on its homologous chromosomes.
The observable expression of the gene present
How many different types of gametes can be formed by plants with a genotype of PpYYrrTt?