BIO 201 EXAM 1 UNCW Latest updated questions and answers + rationales - Grand Canyon University

central dogma of biology

DNA -> RNA -> Proteins

DNA

genetic material that provides a

blueprint for the development and

function of living things

DNA linear sequence of bases

DNA blueprints

DNA replicates

transcription

DNA makes RNA

RNA

linear sequences of bases (nucleotides)

Nucleotides

Monomers of nucleic acids

translation

RNA makes proteins

protein

specific amino-amino chains

that will ultimately produce the phenotype of the living organism

Mad-cow disease

example of a protein that can replicate itself and grow

genotype

genetic composition of an individual

phenotype

A manifestation of genotype: An organism's physical appearance, or visible traits.

mitosis

DNA replication. conserves ploidy.

chromosome

organized structures of DNA,RNA,

and proteins (histone proteins)

True

T/F. Different areas of the chromosome are going to code different genes

histone proteins

A simple protein bound to DNA, involved in the coiling of chromosomes

locus

particular location on a chromosome

occupied by a specific gene

homologous chromosomes

chromosomes of the same

size, shape, that code for the same genes

alleles

a variation of a gene

Meiosis

halves the ploidy. makes gametes for sexual reproduction

properties of life

Reproduction

Growth and Development

Energy use and Metabolism

Response to Environment

reproduction

generation of new individuals that includes transmission of genetic material

growth and development

increase in size or number of cells - series of

changes in the state of a cell, tissue, organ, organism

Energy use and metabolism

set of chemical reactions that happen in the

cells of living organisms to sustain life. respiration. photosynthesis. chemosynthesis

repiration

chemical reactions that convert sugars in to ATP

photosynthesis

process of converting light energy into sugars

chemosynthesis

process of converting inorganic molecules (chemicals CHO) into sugars

response to environment

cells in an organism being able to adapt to a changing environment

cells

internal order and in multicellular organisms have specific arrangement and functions

maintains homeostasis

maintenance of relatively stable environment

despite fluctuating external environment

evolution

changes in the genetic composition of a population of time

Big bang theory

13.7 BYA

Earth formed

4.55 BYA

Water appeared

4 BYA

stromalites appear

3.5-3.7 BYA

stomalites

Layered calcium carbonate

structures formed by

cyanobacteria

how did life originate

1. Nucleotides and amino acids were produced

2. Nucleotides were polymerized to form RNA and/or DNA; amino acids were polymerized to form proteins

3. Polymers became enclosed in membranes

4. Cellular characteristics arose

Nucleotides and amino acids were produced

early atmospheric conditions made is very easy for amino acids (organic molecules) and nucleotides (ACGTU) to form naturally

Miller and Urey

showed that the synthesis of organic molecules

(amino acids) was possible given early atmosphere conditions (water, hydrogen, ammonia, methane)

Nucleotides were polymerized to form RNA and/or DNA; amino acids were polymerized to form proteins

Charged clay surface attracts nucleotides and increased local concentration of nucleotides causes bond formation, forming polymer of RNA

Polymers became enclosed in membranes

Cell-like structures may have originated when polymers were enclosed by a boundary

Formation of a boundary that separated the internal polymers, such as RNA from the environment.

Liposomes

spherical vesicle with at least 1 lipid bilayer

Micelles

tiny spheres of fatty acids

Protobiont

prebiotic molecule that acquired a boundary that allows formation of internal chemical environment that is distinct from external environment

Cellular characteristics arose

Cellular characteristics may have evolved via chemical selection, beginning with an RNA world

chemical selection

when a chemical within a mixture has characteristics that cause it to increase in number relative to other chemicals

adaptation

any heritable behavioral, morphological, physiological trait of an organism that has evolved by natural selection that maintains or increase fitness of an individual in a particular environment

natural selection

differential survival and or reproduction of an individual caused by interactions between the individual and other organisms and its abiotic environment that maintains or increase the fitness of an individual in a particular environment

trait

distinct variant of a physical characterisitics

Fitness

proportionate genetic contribution an individual

makes to future generations

diversification requires

Heritable traits

variation in trait in population

trait affects fitness

LaMark

inheritance of acquired characteristics

Epigenetic

Refers to heritable changes in gene expression that are not the result of changes in DNA sequence. Rat afraid of smell and so were their offspring.

Darwin

1859 On the Origin of Species. Formulated a theory of evolution by natural selection

How are traits inherited?

by passing of factors from parent to offspring

Mendel

worked with peas to discover how traits are passed down and inherited

homozygous

GG gg

heterozygous

Gg

Qualitative (mendelian) traits

traits that occur in a small number of categories

Codominant

both alleles are expressed

quantitative traits

traits that are continuously distributed and determined by multiple genes and interactions with the environment

Natural Selection Adaptions

Variation and Heritable

Variation

Heritable

selective agent

the cause of fitness differences among organisms with different phenotypes. the environmental factor acting on the population.

target of selection

phenotypic trait that selection operates on

directional selection

Selection in favor of one extreme. phenotype characteristics. allele frequently shift over time

stabilizing selection

Selection against both extremes. reduces the amount of variation in population phenotype. Ex. Baby weight (too small-lose heat. too big-complications in giving birth)

distributive selection

Selection for both extremes (against average) Both sides of the stabilizing extremes are favored. When the norm is no longer favored.

balancing selection

selection that maintains genetic diversity within a population. Multiple alleles or circumstances (different versions) are being maintained within a gene pool of a population. Found at larger quantities than expected.

Heterozygote advantage

heterozygotes have higher fitness. By having genetic differences in a population, you have a better chance of survival. Ex. In the presence of malaria, only homozygotes would be effected.

Negative frequency dependent selection

fitness of a genotype decreases over time as that

genotype becomes more common. Ex. accents

Sexual Selection

Selection for mates. Natural selection based on the choice or access to mates

Intrasexual selection

Members of the same sex will directly compete with each other.

Intersexual selection (mate choice)

the opposite sex will choose to mate based on characteristics and actions of the other sex.

What can change populations over time

natural selection and sexual selection

Mutation

Random change in the DNA of an organism

Drifts

Small population sizes, random fluctuations can

influence genetic composition over time

Migration

Movement of individuals from one population to another

Hardy Weinberg

They both created a null model. Whats the expectation of something when its absent?

evolution would not occur in the absence of the

above 5 factors

Bottleneck Effect

the sharp reduction in the size of a population due to environmental or anthropogenic factors

Founder Effect

the loss of genetic variation in a new population was established by a very small number of individuals

Biological Species concept

a species that has the ability to interbreed and produce viable offspring

Allopatric Speciation

occurs when some members of a population/species occupy a habitat that is isolated from others. This will then result in genetic changes and possibly a new species. Accumulation of sufficient differences to generate different

species when some members of species occupy a habitat that is isolated from other individuals

Adaptive radiation

a single ancestral species has evolved into a wide array of descendant species

RIng species

a series of connected populations, each capable of interbreeding with neighboring populations, but there exists at least two "end" populations that are too distantly related to interbreed. Ex. Salamanders will separate into water and mountains and there will be a genetic drift among the 2 populations which will no longer allow them to breed together anymore.

Sympatric Speciation

Speciation within same range - no

geographical barrier.

Polyploidy

organisms that are more than 2N - tetraploid, triploids.

Autopolyploid

polyploid made from the same species

Isolating mechanisms

mechanisms to prevent interbreeding

Prezygotic

prevent formation of a zygote through habitat isolation, temporal isolation, and behavior isolation

habitat isolation

species occupy different habitats never come into contact

temporal isolation

different mating seasons. sexually mature at different times.

behavioral isolation

sexual attraction between a male and female is limited due to differences in behavior. Ex. a bird of paradise trying to attract a seagull

attempting to mate externally

External way to prevent a zygote from forming though mechanical isolation

mechanical isolation

morphological features prevent successful mating (external)

Gametic Isolation

gametic transfer occurs but fails to unite (internal)

Postzygotic

after fertilization, there are mechanisms to prevent development of a fertile offspring

hybrid inviability

the gametes combine and forms the zygote but it doesn't make it past the embryonic stages. The body aborts the zygote.

hybrid sterility

the interspecies hybrid survives birth but can not reproduce

hybrid breakdown

the gametes are going to combine, the zygote will survive birth, and be able to have offspring but the offspring will eventually become sterile.