quiz Flashcards
Who provided Darwin with insight on the concept of a struggle for existence in nature through his writings?
Malthus
Thomas Lyell promoted the concept ‘uniformitarianism’ which refers to __________________.
The view that the geological processes on Earth have not changed over time
In the Miller-Urey experiments, O2 was not available in the reaction chamber.
true
Unlike the model known as gradualism, the theory of punctuated equilibrium does not comply with the general theory of evolution through natural selection. true or false?
false
Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles according to the Hardy-Weinberg equation?
f(A1) = 0.9700, f(A2) = 0.0300
Which one of the following conditions would allow gene frequencies to change by chance?
small populations
Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus, ________.
the allele’s frequency should not change from one generation to the next
In the formula for determining a population’s genotype frequencies, the “2” in the term 2pq is necessary because ________.
heterozygotes can come about in two ways
In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population?
0.80
Which one of these processes describes bottleneck effect?
sudden change in environments that alters gene frequency of a population
What is not a condition for hardy Weinberg?
inbreeding
similarities in mammalian forelimbs is an example of what?
homology
What type of selection favors the extreme phenotypes?
disruptive selection
A donkey and horse mate, this is an example of what?
reduced hybrid fertility
How old is first evidence of life on earth?
3.7 billion
Organism has 1/8 of isotope remaining, how many half lives ago did it die?
3 years ago
(1/2) to the 3rd power
Master regulatory genes are called?
Homeotic genes
homeotic genes are genes which regulate the development of anatomical structures in various organisms such as echinoderms, insects, mammals, and plants.
what are hox genes?
a subset of homeotic genes, are a group of related genes that control the body plan of an embryo along the head-tail axis.
Oxygen revolution changed earth’s environment. Which organism is responsible?
stromatolites
Adaptive radiation can be a consequence of all except?
genetic drift
it can be a result of: Evolutionary innovation, colonization of an isolated region, vacant ecological niches are the reasons for adaptive radiation
Cauliflower and cabbage were selected. This is an example of what?
artificial selection
what is needed for a chemolithotroph to make ATP?
hydrogen sulfide
what eukaryotic supergroup includes protists, animals, and fungi?
unikosta
which organelle occurs in prokaryotes?
ribosomes
which supergroup includes the occurrence of endosymbiosis of cyanobacteria to explain the formation of key organelles?
archaeplasta
red algae and green algae
what is true of all protists?
they are eukaryotic
the placement of all protists in one kingdom caused dissatisfaction among taxonomists mainly because
various pieces of evidence indicate that the kingdom protista can’t be monophyletic
what do dinoflagellates, apicomplexan and ciliate have in common?
all have sacs known as alveoli just beneath their plasma membrane
part of the Alveolates in the SAR
whats the smallest unit that can evolve?
a population
define a population
A group of individuals from the same species that live in the same area and regularly interbreed.
define evolution
Change in allele frequency within a population over time
What is the significant differences between the 4 mechanisms that cause evolution?
- Natural Selection is the only mechanism acting alone can result in ADAPTATION.
- Genetic Drift, Gene Flow, and mutation DO NOT favor certain alleles over others.
- Most of the mechanisms lead to LOST of genetic diversity except for mutation
What is Adaptations? What evolutionary mechanism leads to this?
Adaptations make organisms better suited for their environment.
Natural selection is the only mechanism that can lead to this.
What effect does mutation play?
What is its effects on Genetic Variation?
What is its effect on average fitness?
It produces new alleles.
It increases genetic variation by introducing new alleles
It is random with respect to fitness. Mutations may be beneficial, detrimental, or may have no effect on fitness
Darwin’s theory of evolution described the change an organism’s ____________
phenotype
What is the Hardy-Weinberg equations used as? What does it help determine?
It is used as a null hypothesis to test whether evolution is acting on a specific gene. It helps determine which of the 4 evolutionary mechanisms are acting on the gene in question.
What is a null hypothesis?
A hypothesis that specifies what the results of an experiment will be if the main hypothesis being tested is wrong.
What is the Null Hypothesis of the Hardy-Weinberg equation?
The Null Hypothesis->If no evolution is occurring, then not all the conditions of the Hardy-Weinberg equilibrium are being met.
What is the Hardy-Weinberg Principle?
A principle of population genetics stating that genotype frequencies in a large population do not change from generation to generation in the absence of the 4 evolutionary processes
What ONLY two things are at work when allele frequencies and genotypes in a gene pool remain constant?
1) Mendelian Genetics
2) Recombination (change in combination of alleles) of alleles
What are the two consequences of stabilizing selection?
1) There is no change in the average value of a trait over time
2) Genetic Variation in the population is reduced
In Disruptive Selection, if individuals of one phenotype only mated with others of the same phenotype, what would this later result in?
This would result in speciation–> formation of new species
What is another name for Balancing Selection?
heterozygote advantage
In Balancing Selection, which allele has the advantage?
Neither does, there is a balance between alleles
In balancing selection, which has the advantage: homozygotes or heterozygotes?
Heterozygotes has fitness advantage over either homozygote (recessive or dominant)
What happens to genetic variation in balancing selection?
maintained
What is reproductive fitness?
Your genetic contribution to the next generation
Does natural selection act on phenotypes or genotypes
phenotypes
Since natural selection favors certain alleles over others, what do these alleles experience?
They experience greater reproductive success and are more represented in the next generation.
Why is Genetic Drift more pronounced in a small population?
Since the population is small it has a more of possibility of losing alleles entirely. When this happens, the remaining alleles eventually become fixed.
Genetic Drift causes allele frequencies to change due to blind luck, this is also known as ______________
sampling error
What is Bottleneck effect?
It is a sudden reduction in the number of alleles in a population.
It is random, unlike natural selection that forces out detrimental alleles.
What is a Founder Event and Founder Effect?
Founder Event- A new population is established away from the original species population.
Founder Effect-Group does not contain all the alleles from the original population. Over time this can cause an evolutionary divergence from the main species.
What is Polydactyly and what is this the result of?
Extra fingers or sometimes toes.
Founder’s effect
Over time, what effect can genetic drift have on alleles?
Over time it can lead to random loss or fixation of alleles. –> NO VARIATION!!!
What two types of alleles can mutation result in?
Deleterious alleles and Beneficial alleles
In what organism is mutation rates higher? What two reasons make it higher?
in microorganism such as viruses and bacteria
This is because they have:
1) shorter generation times
2) RNA mutates faster than DNA
*a lot of viruses only have RNA and no DNA
*There are more mechanisms that protect against DNA mutations than RNA mutations
Does inbreeding increase the number of homozygotes or heterozygotes?
homozygotes increase and heterozygotes decrease
What is sexual dimorphism?
“two-forms”
there is a distinct difference between the two genders
typically the male possess the more pronounced form.
What is Intersexual Selection?
One gender gets to be the choosy type (usually female)
Since the females are choosy, the males end up with the unusual phenotype.
What is the benefit of sexual reproduction ?
Genetic Variation –> Meiosis and genetic recombination create variation.
