Bio Final Exam

What is DNA made of? Where is DNA located?

DNA is made up of four building blocks called nucleotides: adenine (A), thymine (T), guanine (G), and cytosine (C). DNA is located in every cell of your body.

What is a gene? Where are genes found?

A gene is a unit of heredity passed from parents to offspring, carrying the instructions for specific traits. Genes are segments of DNA found in within the chromosomes, which is located in the nucleus of every cell.

What is an allele? How are alleles and genes related?

Allele is is a variant form of a gene. They are related because alleles are different versions of the same gene.

What is a genotype? What is a phenotype? How is the genotype related to the phenotype?

Genotype refers to the specific genetic makeup of an individual, while phenotype refers to the observable characteristics or traits of an individual, which are influenced by both the genotype and environmental factors.

What does Homozygous mean? Homozygous recessive? Homozygous dominant?

In genetics, Homozygous means having two identical alleles for a particular gene which means its homozygous recessive.

What does Heterozygous mean? If a trait is Heterozygous, which phenotype is displayed (recessive or dominant)?

Heterozygous means an individual has two different alleles of a gene. If a trait is heterozygous, the dominant phenotype is displayed, as the dominant allele masks the expression of the recessive allele.

You should know that in general capital letters depict dominant (A), lower case depicts recessive (a).

Capital letters generally represent dominant alleles while lowercase letters represent recessive alleles.

Who is Gregor Mendel and what did he do? Why did he use peas for his studies?

Gregor Mendel was an Austrian monk and botanist who is considered the father of genetics for his work on pea plants. He chose to use pea plants because they had distinct traits that were easy to observe and they produced offspring with the same traits as themselves.

You need to know what P, F1, and F2 generation mean in terms of genetic crosses.

P Stands for the parental generation, F1 represents the first filial generation, and F2 denotes the second filial generation.

How does a pedigree chart help us look at genetic traits of our ancestors?

By visually representing the inheritance patterns of specific traits or conditions over multiple generations.

What is incomplete dominance and codominance? How do they display phenotypes differently?

In incomplete dominance is a heterozygote displays a phenotype that is intermediate between the two homozygous like pink flowers from red and white parents. Codominance, on the other hand shows both parental phenotypes expressed in the heterozygote, such as roan cattle with patches of red and white.

You should know there are some traits with more than two alleles.

Human blood type has three alleles, A (codominant), B (codominant), O (recessive) and there is also a protein factor (+ or -) for the protein. A person can be A+, A-, B+, B-, AB+, AB-, or O+, O-.

What are polygenic traits? How are they related to height or eye color?

Polygenic traits are influenced by multiple genes, leading to a continuous range of variations in a population, often resembling a bell curve when analyzed and height or eye color are related to polygenic traits because its influenced by multiple genes not just one.

What are sex linked Genes? Why are males more likely to display recessive traits on X chromosomes?

Sex-linked genes are genes located on sex chromosomes, primarily the X chromosome. Males are more likely to display recessive traits on the X chromosome because they only have one X chromosome.

Why is my mother considered a carrier for the color blindness trait that I display?

Your mother is considered a carrier for color blindness because she likely has one normal X chromosome and one X chromosome with the color blindness gene.

You should know the differences between DNA and RNA

DNA is double-stranded, forming a double helix, while RNA is usually single-stranded.

Know the three types of RNA and what they do.

Three main types of RNA involved in protein synthesis are messenger RNA, transfer RNA, and ribosomal RNA.

You should know the difference between transcription and translation.

Translation produce proteins, while transcription produces mRNA, tRNA, rRNA, and non-coding RNA.

Know the process that takes a gene (from DNA) to mRNA and then to an amino acid chain (protein)

The process of converting a gene’s DNA sequence into a protein involves two main steps: Transcription and Translation.

Fossil Record

Fossil Record shows that past organisms looked similar, but many are distinct from current living species.

What did Lamarck believe about the evolution of species?

Lamarck proposed that species evolve through the inheritance of acquired characteristics.

Who is Charles Darwin and what did he believe about the evolution of species?

Charles darwin was a 19th-century naturalist who is best known for his theory of evolution through natural selection. He believed that species evolve over time through a process where individuals with advantageous traits are more likely to survive and reproduce passing those traits onto their offspring.

What is the process of Natural Selection? What is required for it to occur?

Natural selection is a process where individuals with the advantageous traits within a population are more likely to survive. Natural selection is occurred by variation in traits, heritability of those traits, and differential reproductive success based on those traits.

What do speciation and fitness mean?

Speciation refers to the process by which new species arise, while fitness describes an organism ability to survive and reproduce in its environment.

How does natural selection lead to evolution?

Natural selection leads to evolution by favoring advantageous traits within a population, causing those traits to become more common over generations.

How did the one species of finch radiate to 14 new species of finch = adaptive radiation.

Because each with a unique adaptations for exploiting different ecological niches, primarily due to variations in beak shape and diet.

How does a genetic mutation change an individual’s genotype and how can that change their phenotype?

By changing the sequence of DNA bases.

Natural and Evolution

Remember Natural selection is individual organism. Evolution is the population or species.

How is antibiotic resistance an example of microevolution?

it involves changes in the genetic makeup of bacterial populations over a relatively short period.

What occurs when a population has stabilizing selection, directional selection, and disruptive selection?

In population, stabilizing selection favors average traits, directional selection favors one extreme trait, and disruptive selection favors both extreme traits.

How can phenotypes (beak size of birds) shift in a population? (i.e. some years bird beaks are smaller than other years?)

due to natural selection in response to changes in the environment, particularly food availability.

How is the example of industrial melanism (pollution/moths) an example of directional selection?

Because the increasing frequency of darker moths during industrial revolution and their subsequent decline as pollution decreased demonstrates a shift in the population towards one extreme phenotype (darker moths) due to environmental pressures.

Which selection pressure (stabilizing, directional, disruptive) is most likely to lead to the creation of new species?

Disruptive Selection

What is a genetic mutation, how does it eventually change an organism’s phenotype?

a change in the DNA sequence of an organism. A mutation in a gene can alter an organism’s phenotype by changing the instructions for the building proteins, which in turn can affect the structure, function, or expression of the proteins.

What is gene flow? What is nonrandom mating (sexual selection)?

Gene flow is the transfer of genetic material (alleles) from one population to another. Non-random mating means individuals are more likely to mate with specific types of individuals than randomly chose individuals.

What is Genetic drift (bottleneck effect, founder effect).

Genetic drift is the random fluctuation of allele frequencies within a population due to chance events.

How is artificial selection different than natural selection?

Artifical Selection is driven by human choices, while natural selection is driven by the environment.

How does Allopatric speciation and sympatric speciation create new species?

In allopatric speciation, groups from an ancestral population evolve into separarte species due to a period of geographical separation. In sympatric speciation, groups from the same ancestral population evolve into separate species without any geographical separation.

How does polyploidy (fruits) and hybrids (finches) create new species?

Through process called speciation.

Why are hybrids often not as viable as pure breed species?

Due to genetic incompatibilties between their parental genomes.

What is the biological species concept?

Defines a species as a group of organisms that can interbreed and produce viable fertile offspring, and are reproductively isolated from other groups.

What is the difference between macroevolution to microevolution?

Microevolution refers to small-scale changes within a species, such as adaptation to the environment or changes in gene frequencies, while macroevolution involves large scale processes leading to the emergence of new species over extended time periods.

What is the definition of ecology?

the branch of biology that deals with relations of organisms to one another and to their physical surroundings.

What is Organismal, population, community, ecosystem, landscape and biosphere ecology?

Organism: A single individual living thing.

Population: All the individuals of the same species living in specific area.

Community: All the different populations of organisms living in a specific area.

Ecosystem: A community interacting with its physical environment.

What is an invasive species and what is coevolution?

A non-native organism that, when introduced to an environment, causes harm to the ecosystem, economy, or human health. Coevolution describes the reciprocal evolutionary change between two or more species, where adaptations in one species lead to reciprocal adaptations in the other, often due to their interactions.

Difference between Ecology and environmental science

Ecology is the interactions with each other and their environment, while environmental science is broader and interdisciplinary study of how the earth works, how we interact with the earth and how we can deal with environmental problems we face.

What is a niche and a habitat?

A habitat is the place where an organism lives while a niche is that organism’s role within that environment.

How do abiotic and biotic factors impact a niche?

defines its role and position within an ecosystem.

What is a population?

section, group, or type of people or animals living in area or country.

What is geographic range, abundance, density, dispersion, dispersal?

Geographic Range: This is the maximum area where a species can be found.

Abundance: This refers to the total number of individuals of a species in a given area, giving an idea of how many are present.

Density: Density measures the number of individuals per unit area.

Dispersion: Dispersion describes the spatial pattern of individuals within a given area.

Dispersal: Dispersal is the movement of individuals from their current location to another location, whether it’s to a new habitat or simply moving within their existing range.

What is a community?

a group of people who share a sense of belonging, common interests, or goals and interact with each other in some way.

What is species richness, species evenness, and species diversity?

Species Richness: Simply the count of different species present in an area or community.

Species Evenness: Refers to how equally abundant the different species are in a community.

Species Diversity: Combines both species richness and species evenness to provide a more complete measure of the variety of species within a community.

What is competition? Difference between different species competition and same species competition?

Interspecific competition occurs between individuals of different species, while intraspecific competition happens among members of the same species.

How does minimum resources impact competition?

If one species has a Higher R, it may struggle to reproduce in small patches or when resources are scarce, while a species with a lower R might thrive in the same environment.

What is mutualism? What are facultative or obligate mutual? What are generalist or specialist mutual?

Mutualism is a symbiotic relationship where two or more species benefit from interacting with each other. Mutualism can be either obligate or facultative, and generalist or specialist.

Obligate mutualism means one or both species cannot survive without a relationship.

Facultative mutualism means the species can survive independently but benefit from the interaction.

What is commensalism?

Commensalism describes a relationship where one species benefits, while the other is neither harmed nor benefited.

What is Amensalism?

Refers to a relationship where one species is harmed, and the other is unaffected.

What type of interaction is parasitism?

Consumer-victim interaction where one organism (the parasite) benefits at the expense of an other organism (the host).

What is a trophic cascade, why are keystone/ecosystem engineers important?

A trophic cascade is phenomenon where it changes at one trophic level in a food web and causes effects that ripple through the entire food web, affecting the populations of organisms at other levels. Keystones/ecosystems engineers are important because they play crucial roles in shaping ecosystems.

What is an ecosystem?

An ecosystem is a community of living organisms interacting with each other and their non-living environment.

What is a landscape?

Landscape is a broader area encompassing multiple ecosystems, including their connections and interactions, often with a focus on human-influenced changes and spatial relationships.

How are ecosystem different and the same from landscapes?

Similarities: Both involve interactions between living things and their environment.

Differences: Landscapes consider a larger spatial scale and include human influence, while ecosystems focus on specific interactions within a defined area.

How does energy flow and how do nutrients cycle? Within ecosystems and between ecosystems

Energy flows through ecosystems in a one-way direction, from producers (like plants) to consumers (like animals), and then to decomposers.

what is climate change? why is our climate changing (what is greenhouse effect), what is some evidence that it is changing?

Our climate is changing due to the increased concentration of greenhouse gases in the atmosphere. Greenhouse effect traps heat and leads to global warming. Evidence for this change includes rising global temperatures. melting glaciers, rising sea levels, and changing weather patterns.

If a heterzygous Brown haired person (Brb) with a homozygous recessive blond haired person (bb) what percentage of the offspring would likely have brown hair.

50%

Traits which occur because of recessive alleles are always found less often in populations of people than traits caused by dominant alleles. True/False

False.

What is abiotic?

temp, precip, soils, nutrients, etc.

What is biotic?

predation, competition, mutualism, parasitism etc.