Review Flashcards
What is a cancer cluster
An area where alot of cancer cases are observed
Example Chernobyl
What is the difference between codominance and incomplete dominance
Codominance is when two alleles are equally dominant
Incomplete dominance is a mixing of phenotype a where the offspring shows an intermediate phenotype
What is the difference between an oncogene and protooncogene?
Oncogene is a mutated form of a gene that promotes cancer development
Porto-oncogene is a gene involved in cell division that promotes normal cell division when functioning properly
How is biological fitness estimated
The number of offspring an organism produces is counted and compared to other organisms in the same population.
Why was Darwin and Wallace’s theory a big deal?
It proposed that species change over time and highlighted that importance of variation among species
What is a vestigial trait?
Traits that are reduced or incompletely developed structure that has little to no function in an organism
Name and describe the three types of homololgies
Structural- morphological
Arm bones in birds and in humans
Developmental- embryos
Tail in humans
Genetics- DNA
Humans and fruit flies
Define evolution
Change in allele frequencies over time
List the three types of natural selection and describe them
Directional
Stabilization
Disruptive
What is the difference the difference between pre and post-zygotic isolation
Pre zygotic- before fertilization Temporal/seasonal Habitat/ ecological Behavior no attraction Gametic barrier Mechanical Postzygotic- after fertilization Hybrid viability- zygote does not develop properly or does shortly after birth Hybrid sterility- hybrid will survive but cannot reproduce
Why doesn’t gene flow promote speciation
Gene flow makes two populations more similar over time this speculation is not likely to occur in a population that is continuously mating with members of another population
What is the difference between allopatric and sympatric speciation
Sympatric speciation involves a genetic separation that does not involve physical barriers
Allopatric speciation involves a geographic isolation
Dispersal- colony formation
Vicariance- chance barrier formation
What are the mechanisms of evolution? Be able to define them
Natural selection- certain alleles are favored
Gene flow- movement of alleles between populations
Genetic Drift- random changes in allele frequencies due to chance events
Mutation- production of new alleles
What is the difference between a genetic bottleneck and a fonder effect?
Genetic bottle neck- population size is greatly reduced
Fonder effect- changes in gene frequencies that usually accompany starting a new population from a small number of Individuals
What is the biological species concept?
A way of defining species by whom they can mate with
What is the Hardy-Weinberg Equilibrium?
A mathematical model that says that genotype frequencies don’t chance from generation to generation in the absence of evolutionary chances.
How old is earth
4.6 billion years old
What decreased the number of infections from 1900 to 1940
The introduction of the germ theroy changes in sanitation and changes in nutrition
What disease caused the major spike in deaths in 1918?
The Spanish flu
Fungus are called the great decomposes because they can breakdown what two compounds
Lignin and cellulose
Why are Cyanobacteria important ?
They were the first organisms to do oxygen photosynthesis
They also increased the amount of oxygen in the atmosphere
When was the pre Cambrian period
4.6 billion years ago to 542 million years ago
List 4 hypotheses that might explain the Cambrian explosion ?
Increased oxygen levels
Evolution of predation
Increase abundance and variety of niches
New genes cause by mutations
Why are protist considered a para phyletic group
They do not share a single common ancestor
Not all eukaryotes are protist
Land plants animals and fungi are not Protists
What is a mass extinction
Where at least 60% of a species are wiped out within a million years
Why is the germ theory important ? What did Robert Koch successfully link?
It links a specific bacteria with a specific disease, improved sanitation and removed superstition of whiches and evil causing death
Diseases: cholera, tuberculosis and anthrax
What is the endosymbiosis theory
Lynn Margulis’s theory that claims that mitochondria originated when a bacteria took residence in a eukaryotic cell
What is the out of Africa hypothesis
All humans came from Africa.
How is the nuclear envelope formed
Plasma membrane surrounding the chromosomes folded inward
What is an adaptive radiation? What causes adaptive radiation?
When a single lineage produces many descendant species that live in a wide variety of habitats and use a wide variety of resources
New resources or new ways to exploit resources
What is ecology list the four levels and why is it important
Ecology is the study of how organisms interact in their environment Organismal Population Community Ecosystem It is important to preserve species
What is a biome
Large climatic regions
Defined by vegetation that is driven by temp and rainfall
Observed in patterns of latitude and logitude
What is NPP
Net Primary Production
Amount of energy available to consumers and decomposes
What is a Hadley cell?
Tropical atmospheric circulation pattern
Hot air rises near equator
The air is pushed poleward by the wind current
Cooler less dense air descends over the subtropics
What is an upwelling ?
What causes them ?
Water current that comes up from the bottom of the ocean
Wind blows across the surface of the water
Earth rotation pushes surface water offshore
Nutrient laden water from the bottom of the ocean is pushed upward
What are the three general patterns driving the climates in the USA
Westerly winds blow weather systems until they hit mountain ranges
Precipitation is dumped on the west side of the mountains while dry air moves east
Wet air is circulated north from the Gulf of Mexico
What is the purpose of a food chain
To connect trophic levels in an ecosystem and show the movement of energy and nutrients
What is biomagnification
Increase in concentration of a toxin at higher levels on a food chain
What is toxphene?
What does POP stand for?
A POP or persistent organic pollutant that bio magnifies in ecosystems because it is a fat-soluble which means it cannot be excreted by an organism
What is an estrogen mimic?
Chemicals that is shaped like a steroid that your body misinterprets as a sex hormone
What is a keystone species
A species that has a tremendous effect on the structure and function of an ecosystem
Wolves near Yellowstone park
What is a mad hatter
What causes this syndrome
What ststem is affected within your body
Loopiness silliness
It is caused by mercury poisoning
It affects the central nervous system
What is sustainability
What affects sustainability
Being green
Factors human population growth, unwise use of resources and short term problem solving methods
Is global warming real?
What support do we have ?
Yes
Earth is warming at a much faster rate. Drastic increases in weather variability
What percentage of the egg is lost in the first 3 weeks of development
50%
What is a spontaneous abortion
It is a miscarriage 15% of clinically recognized pregnancies are spontaneously aborted
What are teratagenic birth defects?
What causes them?
How bad are they?
Birth defects that are caused by environmental effects that are experienced by a mother during her pregnancy
Caused by drugs alcohol
Can effect central nervous system and sexual development
What is tholitimoid
Morning sickness pill approved by Europe but not in the US
Causes birth defects
When and how do cells become haploids
Anaphase 1 the homologs separate
If a cat is n=16 what is the organisms diploid number ?
32
How are homologs chromosomes similar ?
Same size and shape they also carry the same genes, but not nessisarly the same alleles.
When does genetic recombination take place
Late prophase 1
Called crossing over
What is meant by the phrase “cost of sexual reproduction”?
A sexual produces more offspring but the offspring are more diverse in sexual reproduction
What is pleiotropy
When a single gene has multiple effects on a phenotype
What is a habitable zone
Distance from sun in which a planet is at a temperature that will allow for liquid water
What causes Down syndrome ?
In Antaphase the chromosomes fail to separate
What is multiple allelism ?
Give example
When genes have more than 2 alleles
Ex ABO blood type
What is meant by the statement “ meiosis is a reduction division”
Chromosomes number is halved
Meiosis two is similar to what process
Mitosis
Meiosis 1
What are the stages and what happens
Interphase- chromosomes replicate in parent cells.
Early prophase- nuclear envelope breaks down and spinal apparatus forms
Late prophase- crossing over of non sister chromatids
Metaphase- homologs line up along meta plate
Anaphase- homologs separate and go to opposite polls
Telophase- cells divid
How is meiosis 1 different from meiosis 2
No crossing over or synphasis
Sister chromatids separate in meiosis 2
What is the theory of spontaneous generation?
Cells came from no where
What is blending inheritance ?
Is the idea that paternal traits blend together so that offspring has an intermediate trait
What is Inheritance of acquired characteristics ?
Paternal traits were modified by experiences and then pass to offspring
What is particulate inheritance ?
Idea that chromosomes maintain there integrity from generation to generation
What is a pure line ?
Are lines that produce offsprings that are the exact same as them they are homozygous
What is a reciprocal cross?
Is used to determine wheatear or not a trait is sex linked.
What is a test cross?
Is used to determine the unknown genotype of an individual with a dominant phenotype
What is independent assortment
Alleles of different genes are transmitted to egg or sperm cells independently of each other
What is segregation
Prior to the formation of eggs and sperm the alleles of each gene seperate so that each gamete only receives one of them
Nondisjunction
Leads to abnormal chromosome compliments. If homologs or sister chromosatids do not separate normally, daughter cells receive wrong number of chromosomes
What is Aneuploid?
To many or to few chromosomes
Chiasma
This is where crossing over occurs late prophase 1 it is X shaped
What is genetic recombination?
Change of combo of alleles on chromosome
What is out crossing ?
Sexual reproduction
What is trisomy?
Three copies of chromosomes
Down syndrome
When ploidy is 2n-1 it is?
Monosomy
What is a hybrid?
Offspring from mating between true breeding parents that differ in traits
What is a Karyotype?
Number and type of chromosomes present
What are sister chromatids?
Same genetic info. Physically joined at a portion called the centromere
What are unreplicated chromosomes?
Single DNA molecule with proteins
What are replicated chromosomes?
Two sister chromatids
What is Gameteogenesis?
Origin of gametes
What is the life cycle?
Sequence from fertilization to offspring
What is Synaptonemal complex?
It holds sister chromatids together
What is asexual reproduction?
Production of offspring without fusing of gametes, no energy waste for males, size of population grows quickly, purifying selection, reduce deleterious alleles, little genetic diversity
What is sexual reproduction?
Production of offsprings through fusion of gametes, genetic diversity, disease resistance
Dihybrid crosses produce what ratio?
9:3:3:1
What is the paternal generation?
F1
What is the Genetic model?
Set of hypothesis that explains how a particular trait is inherited
What is the Locus?
Physical location on a gene
What is the Wildtype?
Most common phenotype for a trait?
What is linkage ?
Physical association among genes on the same chromosome
What is Recombinant ?
Combination of alleles on their X chromosome different from combination of alleles in parent generation
What is the Genetic Map
Shows relative position along particular chromosome
What is Polymorphic ?
More than two distinct phenotype a present in a population because of multiple allelism
What is Gene-by-environment ?
Phenotype is effected by both the environment and genotype
What is Gene-by-gene interaction ?
Phenotype of allele depends on action of alleles on other genes
What is a discrete trait?
Traits of either
Ex wrinkled and non wrinkled seeds
What are Quantitibe traits ?
Differ of degree
Bell curve
What is polygenic inheritance ?
Each gene adds a small Mkubt to value of phenotype
Usually Quantitibe traits
What is a Pedigree ?
Family tree
What is Pedigree autosomal dominant?
Doesn’t skip generations, unaffected parents do not have affected children
What is pedigree autosomal ressesive?
Skips generations carriers unaffected parents can have affected children
What is pedigree sex linked ?
Females or males only affected though can be carriers skips generations
What is pedigree X linked dominant trait ?
Affected males have all affected daughters no affected sons