Bio Exam Flashcards
What is science
The observation, identification, experimental investigation, and theoretical explanation of natural phenomena
What is the scientific method
Standard approach practiced by scientists
Evolution
heritable change in a population of organisms from generation to generation
structure and function
structure determines function
information
Genetic material provides a blueprint for all of the above; offspring are similar to parents
Energy and matter
Energy is acquired from the environment and used to make molecules and maintain an organisms body
Systems
Interactions between parts create novel structures or functions, leading to emergency properties
hypothesis
A proposed explanation for natural phenomenon
theory
A broad explanation of some aspect of the natural world, backed by extensive evidence
Scientific method steps
observation question hypothesis experiment analysis conclusion
peer review process
The researcher
the editor
the reviewer
scientists behind covid sequencing
Dr. Zhang Yongzhen
Dr. Edward Holmes
Scientists behind the covid vaccines
Dr. Katalin Karliko
Dr. Andrew Weissman
Dr. Kizzmekia Corbett
population
a group of individuals of the same species inhabiting the same area; potential for interbreeding
Charles Darwin
proposed that all species of life descended from common ancestor
theory of natural selection
natural selection
The process which eliminates individuals that are less likely to survive in a particular environment. Species that adapt or traits have successful reproduction
variation in traits
heritable traits passed from parent to offspring; genetic
how do characteristics get changed in species overtime
mutations accumulate in genetic material overtime
vertical evolution
occurs within a lineage. the process whereby an ancestral species changes through time (without splitting) to become distinctively different, and therefore recognized as a new species; phyletic evolution.
Atavistic trait
an ancestral trait that reappears after having been lost through evolutionary change. Example: dolphins having hind limbs.
Horizontal gene transfer
is the non-sexual movement of genetic information between genomes. Incoming DNA or RNA can replace existing genes, or can introduce new genes into a genome.
cells
simplest, functional unit of a living organism
Cell theory
- All living organisms are composed of one of more cells
- Cells are the smallest unit of life
- new cells come only prom pre-existing cells by cell divison
Who discovered the endoplasmic reticulum
Keith Porter
Plasma membrane
Barrier
attachment
cell communication
Nucleus
Genetic material
RNA
Ribonucleic acid
Single stranded
Ribosomes
Synthesizes polypeptides
endoplasmic reticulum
stores calcium needed for nerves
Rough ER
ribosomes-RNA- Site of protein synthesis
Smooth ER
Detoxification
Calcium storage
Cell membrane
Phospholipid bilayer
embedded with proteins
What is the three layers of a cell
- plasma membrane
- ACE-2 receptor binds to angiotensin- protein complex in plasma membrane
- Cytoplasm
how does a virus enter the cell
- Binds to ACE-2 receptor
- viral genetic material (RNA)
- hosts ribosomes (Make viral protein)
- -Hosts endoplasmic reticulum (modifies viral proteins
- hosts Golgi apparatus and (packages viral proteins)
- Hosts cell membrane (releases new viruses into the body)
eukaryotic cell
internal compartmentalization
prokaryotic
lack of internal compartmentalization
plant cells
cell wall
chloroplasts
Golgi apparatus
processing, modification, sorting and secreting molecules produced in that cell
where is heritable change found
in a population through generations
what is information flow
expression of genetic material and heritable transmission to offspring
the nucleus of a cell contains what
DNA
what does DNA contain
hereditary material
what does RNA support
proteins calles histones
What is cytogenetics
the cytological approach to genetics, mainly involving microscopic studies of chromosomes
Transmission genetics
The study of mechanisms involved in the passage of genes from one generation to the nest
Population genetics
The study of variation at the genetic level among a group of individuals
Quantitive trait genetics
a quantitive trait is a measurable trait that shows continuous variation and cannot be classified into a few discrete classes
Molecular genetics
The study of the molecular processes underlying gene structure
epigenetic
The study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself
Genomics and bioinformatics
Study of an organisms entire compliment of genes, and use of high-performance computing to analyze sequence data
Four criteria necessary for genetic material
Information
Replication
Transmission
Variation
What are nucleotides
The building blocks of DNA and RNA
What is a “strand” of DNA
A linear polymer strand of DNA and RNA
What is a double helix
the two strands of DNA
What are chromosomes
DNA associated with an array of different proteins into a complex structure
What is a genome
The complete complement of genetic material in an organism
what is the difference between DNA and RNA
DNA is double stranded and base paired
RNA is single stranded and single stranded
What is Central Dogma
DNA replication
What is the process of central Dogma
DNA Transcrition mRNA Translation Polypeptide
What is the process of Information Flow
DNA
RNA
protein
What is a chromosome made of
Genes which are made of DNA
what does the karyotype do
Reveals number, size, and form of chromosomes in an actively dividing cell
how many pairs of sex chromosomes do humans have
one haploid pair (n)
How many pairs of chromosomes does a human have
23 diploid pairs (2n)
pair of chromosomes that are not identical are called
homologous pairs
Autosomes
each homolog nearly identical in size and genetic composition
What happens in G1 phase
Cell growth, passes restriction point, cell becomes committed to enter S phase
What happens in S phase
chromosomes replicate and are called sister chromatids
what happens in G2 phase
Cell synthesizes proteins for mitosis and cytokinesis
What is cytokinesis
follows mitosis to divide the cytoplasm into two daughter cells
How does a cell decide to divide
External factors: environmental conditions, signalling molecules
Internal factors: cell cycle control molecules, checkpoints
What are checkpoint proteins called
Cyclins or cdks
Where are chromatids tightly associated at
centromere
what is the kinetochore
centre of chromatid
mitotic spindle
Responsible for organizing and sorting the chromosome during mitosis.
What is the spindle formed from
microtubules
What are microtubules formed from
tubulin
Three types of microtubules
~Astral microtubules- position spindle in cell
~Polar microtubules- separates two poles
~kinetochore microtubules- attached to kinetochores bound to centromeres
What happens in prophase
chromatids condense into highly compacted structures
pro metaphase
mitotic spindle is fully formed during this phase. centrosome move apart and democrats the two poles
what happens metaphase
pairs of sister chromatids are aligned along a halfway between the poles called the metaphase plate
what happens in anaphase
each individual chromatid is linked to only one pole by kinetochore microtubules
what happens in telophase
chromosomes have reached their respective poles and decondense
what happens in cytokinesis
two nuclei are segregated into separate daughter cells
how is the cytokinesis process different between animal and plant cells
animal cells form a cleavage furrow and plant cells form a cell plate
how does the meiosis process start
haploid cells are produced from cell that was originally diploid
what are the two key differences in meiosis
homologous pairs form a bivalent or tetrad
crossing over
What is a bivalent trend in meiosis
when two homologous chromosomes begin synapsis and form a bivalent
What is the process of crossing over
when a bivalent bond crosses over and forms chiasma
What happens in prophase 1 in meiosis
chromosomes condense, bivalents form
pro metaphase 1
chromatids attach to kinetochore microtubules
metaphase 1
bivalent organized as a double row
anaphase 1
segregation of homologs occurs
connection between bivalents break but sister chromatids stay connected together
What happens in telophase 1
Sister chromatids have reached their respective poles
Are the cells formed after cytokinesis in meiosis haploid or diploid
Haploid
are animal species diploid or haploid dominant
Diploid
Which species are commonly haploid dominant
Fungi
what is a sporophyte
multicellular diploid
what is a gametophyte
multicellular haploid
What is the term we use to describe the normal number of chromosomes
Euploid
What does polyploid refer to
three or more sets of chromosomes
what does aneuploidy refer to
Abnormal number of a particular chromosome
what is the term used when chromosomes do not sort properly
nondisjunction
Consequences of aneuploidy
This imbalance disrupts cell function
what phase are chromosomes replicated in
S phase
a mutation occurs the gene for G1 cyclin, such it is unable to bind to its CDK. How will this affect the cell cycle
The cell will be stuck in G1 phase and will not advance through the cell cycle
Prokaryotic cells are divided by _______
binary fission
How are sister chromatids connected
cohesions proteins
Simple mendelian inheritance
Pattern of traits is determined by a pair of alleles that display a dominant/ recessive relationship and are located on the autosome
X linked inheritance
pattern of traits located on the X chromosome
incomplete dominance
pattern that occurs when the heterozygote has a phenotype intermediate to the phenotype of the homozygote. whit and red flower produce a pink flower
codominance
pattern that occurs when the heterozygote expresses both alleles simultaneously
Epistasis
A type of gene interaction in which the alleles of one gene mask the effects of an allele of another gene
continuous variation
A pattern in which the offspring display a continuous range of phenotype
how many genes does each character have
two
how many alleles are in a gene
two
what phase do the homologous pair split into separate sister chromatids
metaphase I in meiosis
when do the sister chromatids separate
metaphase II in meiosis
What is a locus
the physical location of a gene on a chromosome
What is a species do not involve sex chromosomes
Bees are haploid-diploid
Male is haploid and female is diploid
in a heterozygote what allele does not affect the phenotype
recessive
What is pleiotropy
A mutation in a single gene can have multiple effects on an individual’s phenoptype
genes are almost always pleiotropic
how can a flower become pink from a red and white flower
neither allele is dominant in heterozygote
what non mendelian trait is shown when a black chicken and a white chicken produce a white chicken with black speckles
codominance
a type of gene that depends on another gene to be expressed
epistasis
What represses gene activity
DNA methylation
what proteins support DNA and condense it within the cell nucleus
Histones
what does methylation do to the gene
prevents transcription
species can have the same genotype and different phenotypes, what is a common reason for this
methylation
when a multicellular organism is haploid and only the gametes are diploid
haploid dominant
what does autosomal dominant
every affected person has an effected parent
autosomal recessive
not expressed in all generations . two unaffected people can produce affected offspring
Autosomal dominant phenotype
Normal allele is recessive, allele with mutation is dominant
X linked recessive traits
phenotype determined by a recessive allele on the X chromosome. trait shown in males
X linked dominant
Affected males pass the condition to all their daughter but none of their sons
what is demography
Defining how a population is structured or any features
What is a population
group of interbreeding individual s occupying the same habitat at the same time
Population ecology
studies factors affecting population size and how they change over space and time
What is a niche
resources that species need to survive that other species can use or be used for
dispersion pattern; clumped
most common, resources tend to be clustered, social behaviour may promote this pattern
dispersion pattern: uniform
competition may cause this pattern
dispersion pattern; random
there is an abundance of resources for these species so they scatter or follow others from the same species and randomly choose their habitats
what is specialization
a species that only feed on one species
what causes massive growth in a population
irruption, it is a growth strategy
allopatric speciation
species can emerge if they do not breed with other species
sympatric speciation
interbreeding species
semelparity
produce all offspring in single reproductive event
iteroparity
repeated reproduction at intervals throughout the lifecycle
seasonal iteroparity
distinct breeding seasons
continuous iteroparity
reproduce repeatedly at any time of the year
type I survivorship curve pattern
rate of loss is low and individuals die later in life
type II survivorship curve pattern
uniform death rate
type III survivorship curve pattern
rate of loss is high and die sooner in life
exponential growth
j shaped curve. resources not limiting, prodigious growth
logistic growth
grows exponentially at one point then reaches the carrying capacity
density independent factors
these factors will influence the population no matter what size
inverse density dependant factors
as the factor gets bigger the influence it has on the population gets smaller
density dependant factors
influence gets bigger as population gets bigger
r selected species
high growth rate but poor competitive ability, short lifespan
k selected species
stable populations adapted to exist at or near carrying capacity, long lifespan
what is a fixed action pattern
instinct that does not change. An innate instinct response
what is a sign stimulus
: Something that triggers the initial response. Whatever factor that initiates the response
what is habituation
simplest form of learning
what is non associative learning
-repeated stimulus
-change in response
done without positive or negative reinforcement
associative learning
behaviour is changed through a stimulus and response to the stimulus
classical conditioning
an involuntary response becomes associated with a stimulus that did not originally elicit the response
operant conditioning
animals behaviour reinforced by a consequence. Positive or negative reinforcement
cognitive learning
problem solving
what is the critical period of learning
period of development where species develop irreversible patterns of behaviour
kinesis
movement in response to a stimulus but not direct toward or away from source
taxis
more directed movement
positive is towards the taxis
negative is away from stimulus
geotaxis
heliotaxis
phototaxis
Anemotaxis
- moving down in The earth
- the sun having an effect on direction
- involves light
- changing upwards to the wind
pilotting
using near shore landmarks to remember
orientation
use things like a compass to maintain a barring
navigation
adjusting their course to seek the same target from a different direction
what chemical is used for chemical communication
pheromones
altruism
doing something good to just do it
what mating system causes sexual dimorphism
polygyny- one male + many females
what is polyandry
one female with several males
imprinted genes are
usually methylated and not expressed
what is the organization of genetic material starting from the simplest
nucleotide, DNA, gene, chromosome, genome
when a single gene mutation can have phenotypic effects at multiple stages of development
pleiotropic
prokaryotic cells are characterized by
a cell wall, ribosomes which are involved in polypeptide synthesis
at which phase of mitosis are chromosomes first visible
prophase
a modification of a gene or chromosome that occurs during gamete formation or early development that permanently alters the expression of that gene for the lifetime of the individual
genomic imprinting
the best way to distinguish epigenetic effect
confirm that the change in gene expression is passed from cell to cell but does not involve change in the DNA sequence
how are sister chromatids connects
cohesion proteins
what function does the ACE-2 receptor normally have
binds the hormone angiotensin and helps regulate blood pressure and participates in wound healing
what is an ecosystem
all the organisms in a particular region and the environment in which they live
what is a community
a community refers to all the species that inhabit a common environment and interact with one another
what is exploitation competition
organisms compete indirectly through the consumption of a limited resource
interference competition
individuals interact directly with one another by physical force or intimidation
what is allelopathy
extreme asymmetric competition between plants
resource partitioning
differentiation of niches, both in space and time, that enables similar species to coexist in a community
what is character displacement
Character displacement is the phenomenon of species at the same trophic level evolving through natural selection in response to each other because of some costly interaction.
what is mullein mimicry
noxious species converge to reinforce warning
what is Batesian mimicry
palatable mimic resembles unpalatable model
what are the two types of defences that plants use
mechanical defences and secondary metabolites
how do plant prevent herbivory
host plant resistance
what is commensalism
one member derives a benefit while the other is unaffected
what is defensive mutualism
one specie receives food or shelter in return for defence
bottom up factors include
plant quality and abundance herbivores and the predators that feed on them
food limitations
top down factors
predators and parasites control herbivore or plant prey
what is resistance in ecological communities
the ability of a community to tolerate environmental disturbances
what is resilience in ecological communities
a measure of the speed in which a community returns to its original state following environmental disturbance
what is succession
community change
energy flow
within trophic levels, energy is lost to maintenance and between trophic levels, energy is lost to imperfect efficiency of transfer.
top down factors that can control the population sizes of plants or animals includes which of the following factors
the density of herbivores
rats learning to press a lever to receive food is an example of
operant conditioning
what is the main difference between habituation and conditioning
habituation involves a stimulus with no association, while conditioning involves a stimulus with an association
behaviours that appear to be genetically programmed are called
innate
kinesis is
the cessation of movement in response to a stimulus
top down factors that can control the population sizes of plants or animals include which of the following factors
the density of herbivores
pariatisim usually affects populations in a______ manner
density dependant
chemicals are used to attract mates are called
pheromones
why is a random dispersal pattern quite rare in nature
because resources in nature are rarely randomly spaced
most animals seek to maximize the energy they obtain while minimizing their
energy expenditure and risk of prediation
the per capita growth rate of a population is best defined as
per capita birth rate minus per capita death rate
population growth typically slows down when populations reach carrying capacity because
resource limitation decreases birth rates
what is a factor that drives animal migration
seasonal availability of food
organisms that produce repeatedly are said to be
iteroparous