Biology Unit 1 Flashcards (Prepping for Final)
21.1: TRUE OR FALSE: individual organisms cannot evolve.
TRUE
21.1: For a population to be in HWE (non-evolving state), it must meet the 5 assumptions, which are?
1. Large population 2. Random mating 3. No mutation 4. No gene flow 5. No natural selection
21.4: Define balancing selection
when natural selection maintains two or more forms in a population.
19.3: Explain how biogeography provides support for evolution.
Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area
19.3: Explain how homology provides support for evolution.
Organisms share characteristics because of common descent (homology) OR because of convergent evolution
21.1: Which variables represent allele frequencies?
P & q
21.1: Discuss the major sources of genetic variation in sexually reproducing organisms.
fertilization, independent assortment, and crossing over
22.2: Define allopatric speciation.
gene pools can diverge by mutation, natural selection and genetic drift.
22.2: Define sympatric speciation.
less common, but may occur if gene flow reduced by e.g., habitat differentiation and sexual selection
21.1: Discuss the major sources of genetic variation in asexual organisms.
mutations
21.4: What is disruptive selection?
natural selection advantage at both ends
21.4: What is directional selection?
natural selection advantage in one direction
19:3: Define convergent evolution.
natural selection affects independently evolving species in similar environments in similar ways
21.4: What is stabilizing selection?
natural selection removes extreme variants
1.1: What are the characteristics of life?
ordered evolves maintains homeostasis metabolizes nutrients develops responds to stimuli reproduces made of cells
21.1: Which variables represent genotype frequencies?
p^2 pq q^2
19.2: Explain Darwin's inferences for natural selection.
1. Differential fitness - Differential survival and reproduction of individuals with certain traits in the given environment 2. Evolution - Drives accumulation of adaptive traits in the population over generations
21.4: Explain the 4 reasons why natural selection cannot fashion perfect organisms.
1. Evolution can only act on existing variation 2. Evolutionary history constrains evolution 3. Evolutionary trade-offs exist 4. Chance interacts with natural selection and the environment
22.2: Describe the 3 mechanisms of sympatric speciation.
1. Polyploidy- more than one pair of chromosomes 2. Exploiting new ecological resources not used by parent population 3. Sexual selection- tend to mate based on coloration or other characteristics
19.2: Explain Darwin's observations for natural selection.
1. Variation - Members of a population often vary greatly in their traits 2. Heritability - Many of these traits are inherited from parents to offspring 3. Competition - Species can produce more offspring than their environment can support 4. Mortality - many offspring fail to survive
1.3: 'Gathering and interpreting data' are affected by, and affect in turn, the 3 other arenas of the scientific process, which are?
1. exploration and discovery 2. community analysis and feedback 3. societal benefits and outcomes
22.2: Order the events leading to allopatric speciation.
1st: the populations must be genetically isolated. 2nd: genetic drift occurs. 3rd: reproductive divergence (can't mate)
1.1: Evolution is (choose all that apply) A: An observable pattern B: only a theory C: a process that drives unity and diversity D: a small field of biology E: an educated guess F: something that happens within individuals
A: An observable pattern & C: a process that drives unity and diversity
1.3: Which of the following is a scientific hypothesis? A: Evolution by Natural Selection, B: "Variation in human genetics yields differences in human food preferences, since variation in DNA sequences results in taste receptors with unique functions", C: "If you pet your cat, then it will start purring because it relaxes its vocal cords", D: "If I walk into a room filled with COVID-19 without a mask and without a vaccination, then I will develop COVID-19 symptoms, because my immune system will not be able to fight the foreign pathogen"
B: "Variation in human genetics yields differences in human food preferences, since variation in DNA sequences results in taste receptors with unique functions"
19.2: Which of these examples best exhibits one of Darwin's inferences? A: A bear produces 3 cubs all of which die B: Dandelions that grow faster leave more descendants C: Salamanders with a broad snout produces offspring with broad snouts D: The color of a cardinal's feathers depends on its diet
B: Dandelions that grow faster leave more descendants
19.2: Which of the following observations led to Darwin's major inferences? A: Body parts that are not used deteriorate over time. B: Members of a population vary in their heritable traits. C: Both Answer B and Answer E are correct. D: Organisms only go extinct when catastrophes occur. E: Although organisms can produce huge numbers of offspring, many of these offspring do not survive and reproduce.
C: Both Answer B and Answer E are correct
22.1: Recognize the limitations of the Phylogenetic species concept.
Can be subjective. Requires a lot of information about related species. Requires computational power.
22.1: Recognize the limitations of the Ecological species concept.
Can't be used on extinct organisms. Can be subjective. Species could interbreed even with different ecological niches.
19.3: The figure shows soapberry bug beak size in two populations. Which of the following explains how this is direct evidence for the theory of evolution by natural selection? A: Individual soapberry bugs placed on balloon vines developed longer beaks that they passed on to their offspring B: Soapberry bugs fossils share a similar beak size to soapberry bugs from all other populations C: Soapberry bugs inhabiting mainland Florida, colonized islands off the coast and evolved into lineages with unique beak sizes D: Soapberry bugs who began to adapt to novel food resources evolved smaller beaks than ancestral soapberry bugs
D: Soapberry bugs who began to adapt to novel food resources evolved smaller beaks than ancestral soapberry bugs
22.1: Recognize the limitations of the Biological species concept.
Doesn't work for extinct or asexual organisms, and gene flow sometimes occurs.
19.3: Explain how fossils provide support for evolution.
Fossils show that past organisms differed from living organisms, that many species have become extinct, and that species have evolved over long periods of time; fossils also document the origin of major new groups of organisms.
19.1: Describe how existing scientific ideas from geology contributed to the theory of evolution by natural selection
Hutton and Lyell thought that geologic change could result from gradual, continuous mechanisms.
1.3: Distinguish between examples of hypotheses and predictions.
Hypothesis - A testable explanation for a set of observations, narrower than a theory Prediction - a "If..., then..." statement
21.4: Explain the effect of balancing selection on genetic variation.
It provides a mechanism by which natural selection retains variation rather than eliminating all but the most adaptive traits. This happens because many unfavorable recessive alleles persist because they are hidden from selection when in heterozygous individuals.
19.1: Describe how existing scientific ideas from biology contributed to the theory of evolution by natural selection
Lamarck hypothesized that species evolve, but the underlying mechanisms he proposed are not supported by evidence
19.1: Describe how existing scientific ideas from economics contributed to the theory of evolution by natural selection
Linnaeus developed the two-part, or binomial, format for naming species
21.3: Explain the mechanisms of evolution that do not involve natural selection.
Mutations Genetic drift Gene flow Non-random mating/ selective selection
19.3: Explain how direct observation provides support for evolution.
Researchers have directly observed natural selection leading to adaptive evolution in many studies in diverse organisms.
22.1: Define the Ecological species concept.
Species are defined by their ecological role. Occupy different niches but can interbreed.
22.1: Recognize the limitations of the Morphological species concept.
Subjective about what is similar/different How are distinctive features defined?
22.1: Describe how the biological species concept is inherently connected to the concept of reproductive isolation.
The biological species concept emphasizes reproductive isolation through prezygotic and postzygotic barriers that separate gene pools.
19.3: Contrast the meaning of theory in science with the meaning of theory in colloquial use.
Theory in science - An explanation that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence. Theory in regular use - often means an untested hunch, or a guess without supporting evidence.
19.2: Highlight the 4 keywords that represent Darwin's 2 (or 4) observation that lead to his theory of evolution by natural selection. Darwin developed the inferences that became the theory of evolution by natural selection through several key observations. Darwin noticed that individuals in a population vary in their traits and some of those traits were inherited by the offspring of those individuals. Darwin also noticed that offspring competed for a finite set of environmental resources which ultimately led to the mortality of some of those offspring.
VARY, INHERITED, COMPETED, and MORTALITY.
19.2: Define adaptation
a genetically inherited characteristic that enhances an organism's ability to survive and reproduce within a particular environmental context.
22.1: Define the Biological species concept.
a group of populations whose members have the potential to interbreed in nature and produce viable offspring.
21.3: Define non-random mating/ sexual selection
can result in secondary sex characteristics that can give individuals advantages in mating
21.3: Define genetic drift
chance fluctuations in allele frequencies over generations tend to reduce genetic variation
1.1: Define evolution
descent with modification, an observable pattern and a process that drives unity and diversity
21.1: Define genetic variation.
differences among individuals in the composition of their genes or other DNA sequences
19:3: Define homology
similarity in characteristics resulting from a shared ancestry
22.1: Define the Morphological species concept.
species are distinguished by different structural features
22.1: Define the Phylogenetic species concept.
species are smallest distinguishable units whose members are descended from a common ancestor who possess a combination of defining traits.
21.4: Define frequency-dependent selection
the fitness of a phenotype depends on how common it is in the population (e.g.: "right/ left-mouthed" fish)
19.2: Define biological fitness.
the relative contribution of an individual's genetic material to future gene pools
1.1: Define biology
the scientific study of living & nearly living organisms.
21.3: Define gene flow
the transfer of alleles between populations, tends to reduce genetic differences between populations over time
