Q2 GEN BIO 2 (Mrs. Arenas) Flashcards
In a population, a gene for flower color has two alleles: one for red flowers (R) and one for white flowers (r). If a plant has the genotype Rr, what color will its flowers be, assuming R is dominant?
Red
The flowers will be red because the red allele (R) is dominant over the white allele (r). Even though the plant is heterozygous (Rr), the dominant allele will be expressed in the phenotype.
A mother has brown eyes (Bb) and a father has blue eyes (bb). What are the possible genotypes and phenotypes of their children?
The possible genotypes of their children are Bb and bb.
- Bb: Brown eyes (dominant allele B is expressed).
- bb: Blue eyes (two recessive alleles are present). The phenotypes will be 50% brown eyes and 50% blue eyes.
Two plants with yellow seeds (Yy) are crossed. What are the possible genotypes and phenotypes of their offspring?
The possible genotypes are YY, Yy, and yy.
YY and Yy: Yellow seeds (dominant allele Y is expressed).
yy: Green seeds (two recessive alleles are present).
The phenotypes will be 75% yellow seeds and 25% green seeds.
During gamete formation, a parent with the genotype Aa produces sperm or egg cells. What alleles will the gametes carry?
The gametes will carry either the A allele or the a allele, but not both.
This is due to the Law of Segregation, which states that alleles separate during gamete formation.
A plant has the genotype AaBb for two different genes. How many different combinations of alleles can its gametes have?
The gametes can have four different combinations of alleles: AB, Ab, aB, and ab.
This is due to the Law of Independent Assortment, which states that alleles for different genes segregate independently during gamete formation.
A population of birds on an island has mostly red feathers. A few birds with blue feathers migrate to the island from the mainland. What is this called?
Gene Flow
The introduction of blue-feathered birds increases genetic variation in the island population by adding a new allele for feather color. Over time, gene flow may lead to a higher frequency of the blue allele if it provides a survival or reproductive advantage.
A small population of frogs experiences a sudden drop in numbers due to a disease, leaving only a few individuals. What genetic phenomenon explains this change in allele frequency?
Genetic Drift
The genetic diversity of the population will likely decrease due to the bottleneck effect. The surviving individuals may not represent the full genetic variation of the original population, leading to a loss of alleles.
A small group of squirrels with a rare allele for striped tails colonizes a new forest. How might the allele frequency in the new population compare to the original population?
The allele for striped tails may be more common in the new population due to the founder effect.
When a small group of individuals colonizes a new area, the resulting population will have a limited
gene pool, reflecting the genetic makeup of the founders.
What is the fundamental unit of heredity that carries information about specific traits and is a segment of DNA?
Gene
What are the different versions of a gene called, such as blue, brown, or green for eye color?
Alleles
What term refers to the complete set of genes in an organism?
Genome
What is the term for the genetic makeup of an organism, representing the combination of alleles it possesses?
Genotype
The genotype is the genetic blueprint of an organism, which interacts with the environment to produce the phenotype
What term describes the observable physical or behavioral characteristics of an organism, such as eye color or height?
Phenotype
The phenotype is the result of the interaction between an organism’s genotype and its environment.
What term describes an organism that has two identical alleles for a particular gene?
Homozygous
Homozygous individuals can be either homozygous dominant (e.g., BB) or homozygous recessive (e.g., bb).
What term describes an organism that has two different alleles for a particular gene?
Heterozygous
In heterozygous individuals (e.g., Bb), the dominant allele typically determines the phenotype.
What term refers to an allele that masks the effect of another allele in a heterozygous individual?
Dominant allele
Dominant alleles are expressed in the phenotype even if only one copy is present (e.g., Bb results in brown eyes if B is dominant).
What term refers to an allele whose effect is masked by a dominant allele in a heterozygous individual?
Recessive allele
Recessive alleles are only expressed in the phenotype when two copies are present (e.g., bb for blue eyes).
What is the process of cell division that produces sex cells (sperm and egg) and ensures genetic variation in offspring?
Meiosis.
What term refers to a permanent change in the DNA sequence that can introduce new alleles into a population?
Mutation
Mutations can be caused by errors during DNA replication, environmental factors, or external agents like radiation.
What is the technology called that allows scientists to directly manipulate an organism’s genes?
Genetic engineering
Genetic engineering involves techniques like CRISPR to edit genes, with applications in medicine, agriculture, and biotechnology.
What are the thread-like structures found in the nucleus of cells that contain DNA?
Answer:
Chromosomes
Chromosomes are made up of DNA tightly coiled around proteins and carry genetic information in the form of genes.
What is the molecule that carries the genetic instructions for all living organisms?
DNA
DNA (deoxyribonucleic acid) is a double-stranded molecule that encodes genetic information using four nucleotide bases: A, T, C, and G.
What term describes the differences in genetic material within a population, often resulting from mutations, meiosis, and sexual reproduction?
Genetic variation
The factors that can induce genetic variation are; mutation, gene flow,
The main factor that affects Genetic Drift. Which constitutes to the sudden decrease in a population.
Bottleneck effect
A sudden reduction in population size due to a catastrophic event (e.g., natural disaster) can drastically reduce genetic diversity.
What are the three main sources of genetic variation in a population?
- Mutation: Introduces new alleles.
- Gene flow: Shuffles alleles between populations.
- Genetic drift: Randomly changes allele frequencies, especially in small populations.
What term describes the fundamental concept of genetics discovered by Gregor Mendel, which explains how traits are passed from parents to offspring?
Mendelian inheritance
What term refers to the square diagram used to predict the genotypes of offspring from a particular cross or breeding experiment?
Punnett Square
What term describes the method used to predict the outcomes of crosses involving multiple traits, which is often easier than using a Punnett square?
Forked-line method
What term refers to the inheritance pattern where a trait is controlled by multiple genes, resulting in a range of phenotypes?
Polygenic Inheritance
What term describes the study of how environmental factors can influence gene expression without changing the DNA sequence?
Epigenetics
What term refers to the degree of similarity between the alleles for a specific trait in an organism?
Zygosity
Zygosity describes whether an organism has identical (homozygous) or different (heterozygous) alleles for a particular gene.
What term describes a condition where an organism has only one allele for a particular gene, as seen in males for X-linked traits?
Hemizygosity
emizygosity occurs when an organism has only one copy of a gene, such as males with X-linked genes (e.g., X^R Y).
What term describes a condition where an organism lacks both alleles for a particular gene?
Nullizygosity
Nullizygosity refers to the absence of both alleles for a gene, often resulting in a non-functional or missing trait.¹
What term refers to the fertilized egg formed by the union of two gametes, which develops into a new organism?
Zygote
A zygote is the single cell formed when a sperm and egg fuse during fertilization, containing the full set of chromosomes needed to develop into a new organism.
A farmer grows a field of tomatoes and notices that some plants produce larger fruits than others. The farmer decides to save seeds only from the plants with the largest fruits to plant next year.
What process is the farmer using to improve the size of tomatoes over time?
Artificial selection
Artificial selection, also known as selective breeding, is the process by which humans intentionally choose organisms with desirable traits to reproduce, leading to changes in the population over generations.
In a population of moths, some are light-colored, and some are dark-colored. Over time, the trees in their habitat become darker due to pollution, and the dark-colored moths become more common because they are better camouflaged from predators.
What process explains the increase in dark-colored moths over time?
Natural selection
Natural selection is the process by which organisms with traits better suited to their environment are more likely to survive and reproduce, passing those traits to the next generation.
A population of fish lives in a lake with low oxygen levels. Over many generations, the fish develop larger gills to absorb more oxygen, allowing them to survive better in their environment.
What term describes the process by which the fish become better suited to their environment over time?
Adaptation
Adaptation refers to the process by which a population evolves traits that improve survival and reproduction in a specific environment.
In a population of rabbits, some have longer ears, and some have shorter ears. This difference in ear length is an example of what genetic phenomenon?
Variation
Variation refers to the differences in genetic traits among individuals in a population, which is essential for natural selection to occur.
Other term for artificial selection
Selective Breeding
A population of birds lives on an island where the primary food source is hard-shelled nuts. Birds with larger, stronger beaks are better able to crack the nuts and survive.
What term describes the environmental factor (hard-shelled nuts) that favors birds with stronger beaks?
Selection Pressure
Selection pressure is an environmental factor that influences which individuals in a population are more likely to survive and reproduce based on their traits.
Two populations of the same species of bird are separated by a mountain range. Over thousands of years, they evolve different traits and can no longer interbreed.
What term describes the formation of two distinct species from one original population?
Speciation
Speciation is the evolutionary process by which populations diverge to form distinct species, often due to geographic isolation or other barriers.
A single oak tree produces thousands of acorns, but only a few of these acorns grow into mature trees due to competition for resources like sunlight and water.
What term describes the tendency of organisms to produce more offspring than can survive?
Overproduction
In a population of deer, some individuals are faster runners due to their genetic makeup. During a predator attack, the faster deer are more likely to escape and survive.
Differential Survival
Differential survival refers specifically to the process by which individuals with advantageous traits are more likely to survive in a given environment. It is one component of natural selection, to make it clear.
A green caterpillar sits on a leaf, blending perfectly with the color and texture of its surroundings, making it nearly invisible to predators.
What term describes the caterpillar’s ability to blend in with its environment?
Camouflage
Camouflage is an adaptation that allows organisms to blend in with their surroundings, making them difficult to detect by predators or prey. It often involves colors, patterns, or shapes that match the environment.
A brown moth rests on the bark of a tree, its coloration and texture perfectly matching the tree’s surface.
What type of camouflage involves blending with the color and texture of the environment?
Background matching
Background matching is a form of camouflage where an organism’s appearance matches the color and texture of its surroundings, making it harder to detect.
A zebra’s black and white stripes break up its body outline, making it difficult for predators to recognize its shape from a distance.
What type of camouflage involves patterns that disrupt the outline of an organism’s body?
Disruptive Coloration
Disruptive coloration uses patterns like stripes or spots to break up the outline of an organism’s body, making it harder for predators to recognize its shape.
A shark has a dark upper surface and a light underside, making it less visible from above and below in the water.
What type of camouflage involves darker coloration on the upper surface and lighter coloration on the underside?
Countershading
Countershading is a form of camouflage where an organism’s upper surface is darker and its underside is lighter, minimizing shadows and making it less visible from different angles.
A harmless viceroy butterfly mimics the appearance of a toxic monarch butterfly to avoid being eaten by predators.
What term describes a harmless species mimicking a harmful or unpalatable species?
Batesian Mimicry
Batesian mimicry occurs when a harmless species evolves to resemble a harmful or unpalatable species, gaining protection from predators.
Two species of toxic butterflies evolve to look similar, reinforcing the learning experience for predators to avoid both species.
What term describes two or more harmful species evolving to resemble each other?
Müllerian Mimicry
Müllerian mimicry occurs when two or more harmful or unpalatable species evolve to resemble each other, reinforcing predator avoidance behavior.
A small group of birds colonizes a remote island, and their descendants have a different allele frequency than the original population.
Founder effect
The founder effect occurs when a small group of individuals colonizes a new area, leading to a population with a gene pool that may not represent the original population.
In a small population of insects, a rare allele for blue coloration becomes the only allele present after several generations due to random mating.
What term describes the process by which an allele becomes the only variant present in a population?
Fixation of alleles
In a small population of plants, some individuals with a rare allele for flower color reproduce more frequently by chance, increasing the frequency of the allele in the next generation.
What term describes the process by which alleles are passed on due to chance rather than selection?
Random mating
Random mating refers to the process by which individuals in a population mate without regard to genotype, leading to changes in allele frequencies due to chance.
A scientist observes that a single nucleotide in a gene has been replaced by another nucleotide, altering the protein produced by that gene.
What term describes this permanent change in the DNA sequence?
A mutation is a permanent change in the DNA sequence of an organism, which can alter genetic instructions and lead to changes in traits.
In a gene responsible for blood clotting, a single base pair is deleted, causing a frameshift mutation that leads to a genetic disorder.
What type of mutation involves a change in a single base pair of DNA?
Point Mutation
Point mutations are changes in a single nucleotide base pair, which can include substitutions, insertions, or deletions.
A segment of a chromosome breaks off and reattaches in the reverse orientation, disrupting several genes.
What type of mutation involves large-scale changes to the structure of a chromosome?
Chromosomal Mutation
Chromosomal mutations involve changes to the structure or number of entire chromosomes, such as deletions, duplications, inversions, or translocations.
During DNA replication, an error occurs that is not corrected by the cell’s repair mechanisms, leading to a change in the DNA sequence.
What term describes mutations that occur naturally during DNA replication or repair?
Spontaneous Mutation
Spontaneous mutations arise naturally due to errors in DNA replication or repair mechanisms, without external influences.
A person exposed to high levels of UV radiation develops a mutation in their skin cells, increasing the risk of skin cancer.
What term describes mutations caused by external factors like radiation or chemicals?
Induced Mutation
Induced mutations are caused by external agents such as radiation (e.g., UV light, X-rays), chemicals (mutagens), or viruses.
While observing meiosis in a fruit fly experiment, a geneticist notices segments of DNA are swapped between homologous chromosomes.
What specific process involves the exchange of DNA between homologous chromosomes during meiosis I?
Crossing over
Crossing over is the exchange of genetic material between homologous chromosomes during prophase I of meiosis, creating new allele combinations.
In a plant-breeding study, researchers find that the inheritance of flower color is independent of seed shape.
What process results in the random distribution of homologous chromosomes during meiosis, contributing to genetic variation?
Independent assortment
Independent assortment occurs during meiosis I when homologous chromosome pairs align randomly, ensuring diverse genetic outcomes in gametes.
A scientist observes that offspring in a mouse population show novel combinations of traits not present in either parent.
What term describes the exchange of genetic material during meiosis that results in genetic diversity?
Recombination
Recombination is the broader process during meiosis where genetic material is shuffled between homologous chromosomes, generating genetic diversity in populations.
After years of interbreeding between two animal populations, their genetic makeup becomes nearly identical.
What term describes the effect where high levels of gene flow make populations genetically similar?
Homogenization
Homogenization occurs when extensive gene flow makes populations more genetically similar, reducing distinctiveness.
Wind carries pollen from one population of oak trees to another, resulting in new genetic combinations in the offspring.
What example of gene flow involves the movement of pollen between plant populations?
Plant pollination
Plant pollination, facilitated by wind or pollinators, allows genetic material to move between plant populations, contributing to gene flow.
A herd of deer moves to a new habitat and interbreeds with the resident population, introducing new genetic traits.
What example of gene flow involves the movement of animals between habitats?
Animal Migration
Animal migration enables genetic material exchange between populations, increasing genetic diversity and facilitating adaptation.
A group of people migrates to a new region, contributing to genetic diversity in the local population over generations.
What example of gene flow involves the movement of people across geographical regions?
Human Migration
Human migration contributes to gene flow by introducing new genetic material into local populations, influencing genetic diversity and evolution.
In a bird population, individuals with brightly colored feathers are more likely to choose similarly vibrant mates.
What term describes mating that occurs when the probability of two individuals pairing is not equal for all pairs?
Non-random mating
Non-random mating occurs when individuals select mates based on specific traits rather than at random, influencing genetic diversity in a population.
In a human community, people with similar educational backgrounds are more likely to marry each other.
What type of non-random mating involves individuals choosing mates that are similar to themselves?
Positive Assortative Mating
Positive assortative mating occurs when individuals prefer mates with similar traits, increasing homozygosity for certain alleles.
In a plant population, flowers prevent pollination from closely related individuals by encouraging cross-pollination with genetically different plants.
What type of non-random mating involves individuals preferring mates that are different from themselves?
Negative Assortative Mating
A small isolated animal population shows an increased prevalence of genetic disorders due to repeated mating among close relatives.
What type of non-random mating involves closely related individuals breeding, increasing homozygosity?
Inbreeding
Inbreeding involves mating between closely related individuals, which increases the likelihood of recessive genetic disorders and homozygous genotypes.
A research team discovers evidence suggesting that organic molecules capable of forming life were found on a meteorite that landed on Earth.
What theory suggests that the building blocks of life may have come from another planet?
Theory of panspermia
The theory of panspermia (also called exogenesis) posits that life or its precursors arrived on Earth via comets, meteorites, or cosmic dust from outer space.
A scientist simulates conditions of early Earth in a lab and observes the formation of amino acids, supporting the idea that life may have originated in a mixture of organic compounds.
What theory suggests that life began in a chemical “soup” of organic molecules on early Earth?
Primordial Soup Theory
The primordial soup theory proposes that life originated in a mixture of organic compounds and environmental catalysts, leading to the formation of living cells.
Scientists find 4.1-billion-year-old fossils of a microbial mat in Western Australia, possibly representing Earth’s earliest forms of life.
What evidence is often used by scientists to study life forms from Earth’s distant past?
Fossils
Fossils are the preserved remains or traces of ancient organisms, providing crucial evidence for understanding Earth’s history and the evolution of life.
A geology professor explains that the Earth’s history is divided into distinct periods based on the types of life-forms that existed.
What system is used to divide Earth’s history into specific time periods based on life forms and rock formations?
Geologic time scale
The geologic time scale is a chronological framework used to classify Earth’s history into eras, periods, and epochs based on fossil evidence and major geologic events.
A geology student is learning about divisions of time such as eras and periods used to represent different stages of Earth’s history.
What are the divisions of the geologic time scale based on rock formations and the fossil record called?
Geochronologic units
Geochronologic units are divisions of time in the geologic time scale, such as eras, periods, and epochs, based on changes in life-forms and rock layers.
What is the longest subdivision in the geologic time scale, defined by the abundance of certain fossils?
Eons
What subdivision of the geologic time scale comes after eons and is characterized by significant changes in the fossil record?
Eras
Eras are major divisions of geological time marked by widespread changes in life forms, often ending with mass extinction events.
A paleontologist is analyzing fossils from a time when dinosaurs thrived.
What geologic subdivision is based on types of life existing at specific times?
Periods
Periods are divisions of geologic time characterized by the types of life forms that were dominant during that time.
A scientist uses fossils to correlate and sequence rock layers from different regions.
What technique uses fossils as guides to determine the relative age of rock layers?
Biostratigraphy
Biostratigraphy uses index fossils—species with a wide distribution but a short time span—as guides to identify chronostratigraphic units.
What is the shortest subdivision in the geologic time scale marked by differences in life forms?
Epochs
Epochs are the smallest divisions of geologic time, often defined by local differences in fossil life forms.
A geologist wants to determine the exact age of a volcanic rock sample in years.
What dating method assigns a specific age to a rock based on the properties of its atoms?
Absolute Age Dating
Absolute age dating uses radioactive decay to assign precise ages to rocks, unlike relative dating, which only sequences events.
A scientist is dating a 5,000-year-old piece of ancient wood.
What dating method measures the decay of carbon-14 to determine the age of once-living materials?
Radiocarbon Dating
Radiocarbon dating measures radiation emitted by decaying C-14 isotopes and is effective for dating materials up to about 70,000 years old.
A geologist finds a rock feature that cuts through several older rock layers.
What principle states that a rock feature cutting across another must be younger than the feature it cuts?
Principle of cross-cutting relationships
This principle asserts that any geological feature that cuts across other layers is younger than the layers it intersects.
rock contains fragments of a different type of rock embedded within it.
What principle states that rock fragments included within another rock must have formed first?
Inclusion Principle
The inclusion principle states that fragments of rock within a second rock type must predate the formation of the enclosing rock.
A geologist uses current volcanic activity to explain past volcanic eruptions.
What theory suggests that the present is the key to understanding Earth’s past geological processes?
Uniformitarianism
Uniformitarianism, proposed by James Hutton, holds that current geological processes have operated throughout Earth’s history.
A paleontologist is studying different rock layers and noting that they contain similar fossil assemblages.
What principle states that rock layers can be identified by the fossils they contain, and these fossils occur in a consistent order through time?
Principle of biologic succession
The principle of biologic succession, developed by William Smith, states that fossil assemblages in rock layers are unique and can be used to identify and correlate strata across different regions.
Who was the geologist that published “Principles of Geology” and introduced ideas like the principle of cross-cutting relationships and uniformitarianism?
Charles Lyell
Who is the geologist credited with developing the theory of uniformitarianism and believed that the Earth’s surface was constantly changing?
James Hutton
James Hutton, a Scottish geologist, is considered the father of modern geology, proposing the theory of uniformitarianism, which emphasizes that the processes we observe today have shaped the Earth throughout its history.
Who is the surveyor who first used fossil assemblages to identify and correlate rock layers over vast distances?
William Smith
William Smith, an English surveyor, is credited with developing the principle of biologic succession, using fossils to correlate strata and establish the relative ages of rock layers.
Who is the naturalist credited with developing the theory of natural selection and proposing that species evolve over time?
Charles Darwin
Charles Darwin, along with Alfred Russel Wallace, is famous for developing the theory of natural selection, which explains how species evolve over time through the survival and reproduction of individuals with favorable traits.
What is the estimated age of Earth, and what were the early conditions like?
4.54 billion years old, with early conditions characterized by intense heat, volcanic activity, and frequent asteroid impacts.
What were the earliest known life forms, and when did they appear?
Single-celled microorganisms (prokaryotes) appeared around 3.5 billion years ago.
The earliest life forms were prokaryotes, which lacked a nucleus and were likely similar to modern bacteria and archaea.
What evolutionary development revolutionized Earth’s atmosphere by releasing oxygen?
Photosynthesis by cyanobacteria.
Photosynthesis by cyanobacteria introduced oxygen into Earth’s atmosphere, paving the way for aerobic life forms
Around 2.4 billion years ago, oxygen levels in Earth’s atmosphere increased dramatically, leading to significant environmental changes.
What event marked a dramatic increase in atmospheric oxygen around 2.4 billion years ago?
The Great Oxygenation Event
The Great Oxygenation Event was a period when oxygen produced by photosynthetic organisms accumulated in the atmosphere, leading to the extinction of many anaerobic species and the evolution of aerobic life.
What type of cells evolved around 1.8 billion years ago, leading to greater biological complexity?
Eukaryotes
Eukaryotic cells, which contain a nucleus and membrane-bound organelles, evolved from prokaryotic ancestors and enabled the development of multicellular organisms.
When did the first multicellular organisms appear, and what major event followed?
Around 600 million years ago, followed by the Cambrian Explosion.
The Cambrian Explosion, around 541 million years ago, was a period of rapid diversification during which most major animal phyla appeared.
During the Proterozoic Eon, Earth’s land masses gathered to form a supercontinent.
What major geological and biological events occurred during the Proterozoic Eon?
Formation of Rodinia and oxygen production by cyanobacteria.
The Proterozoic Eon saw the formation of supercontinents and the rise of oxygen-producing cyanobacteria, which transformed Earth’s atmosphere.
During the Archean Eon, Earth’s interior was still hot and active.
What characterized Earth’s surface during the Archean Eon?
Volcanic activity and the formation of small islands.
What were Earth’s surface conditions like during the Hadean Eon?
Molten surface with oceans of liquid rock and boiling sulfur.
The Hadean Eon was a time of extreme heat and volcanic activity, with no solid crust or stable atmosphere.
What event marked the rapid diversification of animal life around 541 million years ago?
The Cambrian Explosion.
What is the correct chronological order of the major eons in Earth’s history?
Hadean, Archean, Proterozoic, Phanerozoic
What are the three periods of the Cenozoic Era in chronological order?
Paleogene, Neogene, Quaternary
What era is known as the “Age of Mammals,” spanning from 66 million years ago to the present?
Cenozoic Era
Which period saw the extinction of large mammals such as mammoths and saber-toothed cats?
Quaternary Period
Which epochs belong to the Paleogene Period, and what are their distinguishing characteristics?
- Paleocene (diversification of small mammals),
- Eocene (greenhouse-like climate),
- Oligocene (cooler climate, glaciers)
What periods make up the Mesozoic Era in chronological order?
Triassic, Jurassic, Cretaceous
What major environmental and species changes occurred during the Quaternary Period?
Extinction of large mammals and birds, including mammoths and saber-toothed cats
What is the geologic era known as the “Age of Reptiles”?
Mesozoic Era
What is the correct order of the periods in the Paleozoic Era, from oldest to most recent?
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian
In which period did the first birds appear, while dinosaurs flourished during their “golden age”?
Jurassic
During which Mesozoic period did the first dinosaurs appear?
Triassic
What period first saw land plants and coral reefs emerge?
Silurian
What period ended with the mass extinction of most dinosaurs?
Cretaceous
What era featured the rise of land plants, marine invertebrates, and the emergence of fish?
Paleozoic Era
Which period of the Paleozoic Era is known for the explosion of life?
Cambrian
What period in the Paleozoic Era marked the dominance of marine invertebrates like trilobites?
Ordovician
Which Paleozoic period is known as the “Age of Fishes”?
Devonian
What period ended with the extinction of 90% of Earth’s species?
Permian
What period featured the first seed plants and reptiles?
Carboniferous
Which epoch is the current interglacial period within the Quaternary Period?
Holocene
Which period in the Cenozoic Era marked the emergence of kelp forests and grasslands?
Miocene
What epoch within the Paleogene Period featured a greenhouse-like climate and the junction of India with Eurasia?
Eocene
During which epoch did plants adapt to cooler, seasonal climates as glaciers first appeared in Antarctica?
Oligocene
Which epoch of the Paleogene saw the diversification of placental mammals after the Cretaceous extinction?
Paleocene
What is the correct order of epochs in the Cenozoic Era, from oldest to most recent?
Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Holocene
Which epoch of the Neogene Period was marked by the emergence of apes living on African plains?
Pliocene
During which epoch did large predatory mammals and small rodents evolve alongside new bird species?
Miocene
What epoch within the Quaternary Period was characterized by alternating glacial and interglacial periods?
Pleistocene
How long ago did the Cenozoic Era begin?
66 million years ago
How long ago did the Mesozoic Era span?
252 to 66 million years ago
How long ago did the Paleozoic Era span?
541 to 252 million years ago
How long ago did the Precambrian Era begin?
4.6 billion years ago
When did the earliest known life forms, single-celled microorganisms, first appear on Earth?
Around 3.5 billion years ago
Around when did the Great Oxygenation Event occur?
Around 2.4 billion years ago
When did eukaryotes, complex cells with a nucleus, evolve?
Around 1.8 billion years ago
When did the first multicellular organisms appear?
Around 600 million years ago
What term describes the gradual change in living organisms over successive generations, often driven by mechanisms like natural selection?
Evolution
Evolution is the process by which living organisms undergo gradual changes over successive generations, often driven by mechanisms like natural selection, genetic drift, and gene flow.
What term describes the complete disappearance of a species from Earth?
Extinction
Extinction is the complete disappearance of a species, which can result from various factors such as climate change, habitat loss, overhunting, and natural disasters.
What term describes periods of widespread and rapid extinction of species, often triggered by catastrophic events such as asteroid impacts or volcanic activity?
Mass extinctions
Mass extinctions are periods in Earth’s history when a large number of species go extinct in a short geological time frame, often due to catastrophic events like asteroid impacts, volcanic eruptions, or rapid climate change.
What name is given to the most severe mass extinction event in Earth’s history, which occurred around 252 million years ago and wiped out a large percentage of life on Earth?
The Great Dying
The Great Dying, also known as the Permian-Triassic extinction, was the largest mass extinction event in Earth’s history, resulting in the loss of up to 90% of marine species and 70% of terrestrial species, likely caused by extreme volcanic activity and climate change.
During which geologic period did the Great Dying occur?
The Permian Period
