Tag Archive | "genetic drift"

Need Biology Help Please!?


1)Plasmids are transferred from one bacterium to another through
conjugation.
chemoautotrophs.
flagellae.
bacterial capsules.
2)The origin of membrane-enclosed cells is thought to include the formation of
extremophiles.
microspheres.
ribosomes.
eukaryotes.
3)Two species occupying the same niche would be __________ with each other.
in competition
at peace
coevolving
in harmony
4)The mineralized remains of an organism is called a(n)
fossil.
homologous feature.
adaptation.
population.
5)Calling a species by its genus and species name, such as Homo sapiens, is using
cladistics.
binomial nomenclature.
phylogeny.
taxonomy.
6)The isolation of two groups within a population from each other, and their adaptation to the point of being no longer able to interbreed is called
population genetics
gradualism.
speciation.
convergence.
7)The ecological role of a species is its
niche.
energy pyramid.
habitat.
community.
8)A classification system based solely on derived traits is called
phylogeny.
cladistics.
domains.
genetic drift.
9)The theory that organelles originated as separate prokaryotic symbionts is called
relative dating.
endosymbiosis.
mass extinctions.
geologic time.
10)Comparing a new fossil to a previously-dated fossil in order to determine its age is a form of
relative dating.
radiometric dating.
half-life.
geologic time.
11)Applying crystal violet stain, followed by iodine, alcohol, and safranin, a bacterial culture looked purple. The bacteria was
transduced.
Gram positive.
transformed.
Gram negative.
12)All the members of one species in a given area is its
biodiversity.
carrying capacity.
growth.
population.
13)The disappearance of a species from the Earth is referred to as
deforestation.
extinction
biodiversity.
recycling.
14)When a population does not show any net change in its gene pool, it is
using random mating.
in genetic equilibrium.
about to go extinct.
isolated reproductively.
Please help me.

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Approximately 65 Million Years Ago…?


Approximately 65 million years ago, a mass extinction occurred on planet Earth. Layers of soil dating back to this time contain large amounts of the radioactive element iridium. This indicates that a large asteroid or comet struck Earth, throwing up huge clouds of debris, which would block much of the sunlight. Food became very scarce. Half of the marine species and nearly all of the dinosaur species went extinct during this time. Soon after the cloud settled, the surviving species of mammals rapidly diversified and filled the niches left empty by the dinosaurs. What evolutionary event was represented by this asteroid collision and the resulting cloud?
a. mutation
b. gene flow
c. genetic drift
d. natural selection
Thanks!

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Somone Answer These Plox?


. A population of foxes experiences an exponential growth. After this period of growth, the birth rate within the population slows down. What has happened within the population? The population has gone through ecological succession. The environment of the population has most likely reached its carrying capacity.
The population has experienced competitive exclusion. The habitat of the population has experienced population dispersion.
14. Which type of population dispersion is shown below?
even random
clumped sparse
15. Which of the following factors is an example of interspecies competition? a population of zebras and a population of wildebeests grazing in the same region a population of wild horses that share a watering hole
a pack of wolves that hunt deer and moose a population of penguins that feed on fish
16. Lily and her classmates decide to plant a garden at a local park. Lily decides that it would be a good idea to investigate the local plant life of the region before the class plants the garden. Why does Lily investigate local plant life before her class decides what vegetation to plant? Lily wants to make sure that the class does not plant exotic or nonnative plants in the garden. Introduced species can be harmful to local habitats. Lily wants to make sure that the class plants only nonnative vegetation, so that the plants will not have to compete for resources within the environment.
Lily wants to make sure that the plants will be able to survive in the local environment. Lily wants to make sure that the native plants will not interfere with the growth of the class’s garden.
17. The fungus on the ear of corn in the image below is called corn smut. If an ear of corn is infected with the fungus, it has to be destroyed, or it could spread and cause harm to the entire population. The fungus found on the ear of corn is an example of _____.
natural selection genetic drift
a limiting factor gene flow
18. Which of the following populations is the most likely to have reached its carrying capacity? a population of birds that inhabit a large forest where resources are abundant and competition is low a population of birds that inhabit a small, wooded area where resources are scarce and competition is high
a population of birds that inhabit a small, wooded area where resources are abundant and competition is high a population of birds that inhabit a large forest where resources are limited and competition is low
19. Which of the following is the most likely outcome for a community that has multiple species with high population density? The species within the community will experience genetic drift because of the limited habitat space. The species within the community will undergo mutation to better adapt to the limited habitat space.
The species within the community will share niches to better adapt to the limited habitat space. The species within the community will experience high levels of interspecies competition over habitat space that could lead to competitive exclusion.
20. Why do populations that have clumped population dispersion compete and rely on each other more than organisms that live in populations with even and random dispersion? The organisms in even or random populations generally do not require the same resources. The organisms that live in clumped populations generally do not require the same resources.
The organisms that live in clumped populations share a more compact habitat space. Organisms that live in even or random populations experience greater interspecific competition.
21. Why does the presence of mimicry reflect how interactions shape community structure? Mimicry limits the ability of predators to find food. Mimicry exists only in communities that experience high competition.
Mimicry increases prey survival, increasing the food supply for predators. Mimicry only develops as a result of the interactions that exist between predators and prey in a community.
22. Mycorrhizae are a type of fungi that grow on the roots of plants. In order to survive, the fungus must attach itself to a host. In turn, the fungus produces high amounts of nitrogen that is released into the soil and helps the host plant grow and complete life functions. Which type of relationship best describes this interaction? mutualism parasitism
commensalism predation
23. The polar bear population is found naturally only in the extremely cold climate of the Arctic Circle. As a result, the polar bear has adapted in several ways to make it better suited to living in these climates. Which of the following is an adaptation that is a result of the polar bear’s cold climate?
its massive size, which helps it overpower prey the long hair found between the pads of its feet, which helps it walk on icy surfaces
the stiff hairs found on its hind legs and broad paws, which help it swim

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Some Biology Questions?


1.Evolution occurs:
A) by altering physical traits but not behavioral traits.
B) only when the environment is changing.
C) only via natural selection, genetic drift, migration, or mutation
2.Thomas Malthus’s 1798 work, Essay on the Principle of Population, greatly influenced Darwin. Which of the following statements best summarizes Malthus’s idea?
A) Animals are able to pass to their offspring characteristics that were acquired in their lifetimes.
B) Individuals with better competitive abilities are more likely to survive and pass their genes to the next generation.
C) Isolated populations of organisms tend to differentiate into new species to fill different niches.
D) People reproduce much more quickly than their resources do. This results in competition for food and space, and in suffering and death.
3.Which of the following groups would be placed nearest the fungi in a phylogenetic tree based on DNA sequences?
A) gymnosperms
B) cyanobacteria
C) animals
4.To which one of the following is the bat’s wing NOT homologous?
A) the lion’s foreleg
B) the dragonfly’s wing
C) the human’s arm
D) the bird’s wing
5.The classic experiments performed in the 1950s by Harold Urey and Stanley Miller, were the first to show that:
A) simple organic molecules, such as amino acids, could form spontaneously in the laboratory under chemical conditions mimicking those of primitive Earth.
B) water (H2O) could be separated into atmospheric oxygen and H2 gas.
C) naturally occurring antibiotics, such as penicillin, could be used to treat bacterial diseases.
6.Which of the following molecules was NOT present in the pre-biotic environment?
A) ammonia (NH3)
B) methane (CH4)
C) molecular oxygen (O2)
D) water (H2O)
7.Much of what is known about the history of the origin of life came from:
A) written history.
B) word of mouth.
C) educated guesses.
D) the study of fossils.
8.The biological species concept is primarily based on:
A) reproductive isolation.
B) phylogenetic history.
C) ecological niche.
9.The biological species concept:
A) is infrequently used because it is inapplicable to many organisms.
B) states that any organisms that are biologically similar constitute a species.
C) defines a species as any group of actually or potentially interbreeding species that produce viable offspring

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