anbi_139_2025_05_05_043145 Flashcards
(280 cards)
1
Q
Give an example each of heritable and non-heritable variation
A
Eye color (heritable), hobbies (non-heritable)
2
Q
Give an example each of random and non-random events during biological evolution
A
Mutation (random), survival under certain environmental conditions (non-random)
3
Q
What happens to the rate of evolution in small populations?
A
the rate gets higher, evolution accelerates
4
Q
What are the three key ingredients of biological evolution
A
Replicating entities, Heritable Variation, Differential Reproduction
5
Q
What is the difference between somatic cells and germ cells?
A
Somatic cells are the majority of the cells in the body, germ cells are the ones that can give rise to gametes
6
Q
Can somatic mutation be passed on to the next generation?
A
No, only germ line mutations can
7
Q
Are most mutations dangerous to the survival of the individual in which they occur?
A
NO, most mutations appear to be neutral
8
Q
Why is the evolutionary tree of life made up of branches?
A
Because most of the time, once two populations or organisms have stooped exchanging DNA, they become incompatible and cannot start exchanging DNA again.
9
Q
Why is it impossible to place viruses on the tree of life?
A
Because viruses do not contain any DNA that can be directly compared to the DNA in cellular life forms.
10
Q
What does convergent evolution mean?
A
Independent evolution leading to similar outcomes (biochemistry: caffeine, anatomy: spindle shaped swimmers, behavior: paternal care of the young)
11
Q
What four very different perspectives on disease can be considered?
A
Patient, Doctor/Care provider, Evolving Pathogen, Evolving Host.
12
Q
Give a proximate mechanisms for disease:
A
mutation in important immune gene, e.g. interleukin 10 (IL10)
13
Q
Give an evolutionary explanation for disease
A
Hygiene hypothesis
14
Q
What is the size of a human cell, a bacterium and that of a virus?
A
Human cell 30 micrometers, bacterium ~ 3 micrometers, virus ~100 nanometers.
15
Q
Can a mutation in a single gene cause disease?
A
Yes, there are over 4000 human diseases caused by a single gene mutation!
16
Q
What is the pathogen that causes malaria?
A
Several species of the protozoan called Plasmodium.
17
Q
What is the pathogen that causes tuberculosis?
A
The bacterium Mycobacterium tuberculosis.
18
Q
What is the pathogen that causes HIV/AIDS?
A
The HIV virus, a lentivirus belonging to the group of retroviruses
19
Q
why is the name SIV a misnomer?
A
Because the virus does not cause immunodeficiency in most non-human primates.
20
Q
Why is it impossible to rid the world of influenza A virus?
A
Because there is a huge and diverse reservoir of influenza viruses in wild water birds
21
Q
What is unusual about prion diseases?
A
They are cause by a mis-folded protein, not by a living, replicating organisms. A mis-folded protein from outside the body, causes additional mis-folding of the patient’s own prion molecules.
22
Q
What is the origin of the word vaccination?
A
the latin word vacca=cow, given that cowpox was used to immunize humans against smallpox.
23
Q
Why is the difference between variolatiin and vaccination?
A
Variolation is immunization using smallpox virus, vaccination is immunization against smallpox using the related cow pox virus.
24
Q
What is the difference between variolation and vaccination?
A
Variolation (Inoculation) uses scabs from smallpox patients to immunize naive persons, while vaccination uses scabs from cows infected by cow pox to immunize against smallpox. Vaccination has since been applied to other methods of immunization.
25
How long is the haploid genome of each of our cells and how many “letters” base pairs dos it contain?
About 1 meter long and it contains 3 billion bp
26
How does all this DNA fit in a single cell?
By extremely compact packaging into chromatin and further compacting into chromosomes.
27
What does chromatin consist of?
Histone and non-histone proteins and DNA
28
Give three example of chromosomal changes during evolution?
Fusion, Inversion, reciprocal translocation.
29
How can different parts of the genome have different histories?
Genetic recombination breaks apart and brings together different parts of the genome. The further apart on a chromosome two segments of DNA are, the likelier that these do not share the same precise history.
30
What 2 different parts of our genomes do not get reshuffled but are rather inherited from one parent only?
Mitochondrial DNA and most of the Y-chromosome
31
What are the four major classes of biomolecules?
Nucleic acids, proteins, lipids and glycans
32
How many pieces of DNA are there in the nuclear genome of a human?
46 , visible as chromosome when a cell is dividing.
33
What is a haplotype?
A unique combination of DNA variants along the same strand of DNA.
34
What are post translational modifications ?
Changes to protein molecules after these have been synthesized (translated from mRNA).
35
It is possible that our entire genome (all 3 billion basepairs of it) is a “gene”
Possibly
36
What could be the advantage of our genomes having multiple versions (copies) of the same gene (e.g. hemoglobin)?
Slightly different variants of the same gene can be used at different times during development and life (embryonic, fetal, adult).
37
What is an enhancer (in the genome)?
A stretch of DNA that interacts with transcription factors and the promoter of genes to regulate their expression
38
Give two examples of RNA that is functional despite the fact that it does not code for a protein:
Ribosomal RNA is part of the RNA translating machinery of a cell, micro RNA takes on a 3 D fold and can interact with proteins to modify gene expression.
39
Give four characteristics of the genome that can affect gene expression?
Chromatin remodeling, histone modification, DNA methylation, non-coding and micro RNA (+RNA binding proteins, DNA-binding proteins = transcription factors)
40
What does the queen bee have to do with epigenetic?
Enzymes acting on histone modifications in the royal jelly produced by worker bees and fed to the developing queen larva cause the same egg to become a queen rather than a worker.
41
How can the chemical modification of histone proteins influence gene activity?
Histone modifications can change the accessibility of gene expression machinery to DNA.
42
What the ratio of human to microbial cells in and on your body?
Roughly 1 to 1
43
How many times smaller than you is an average bacterium?
One million times
44
How are microbiota like micro Serengetis?
They represent complex communities of multiple species.
45
How could human hosts benefit from genes in the genome of their microbiome?
Microbial enzymes can digest food and generate vitamins.
46
Name two ways in which Biological and Cultural inheritance are similar and two ways in which they differ.
Both types of inheritance represent transmission of information, both are affected by change over time; cultural inheritance does not include the inheritance of genetic information and it can spread horizontally or even from younger to older generations.
47
Give an example of an important human technology that does not fossilize?
Fiber technology, ropes, strings, baskets, fabrics.
48
How can personal names and language affect individual behavior?
It allows for reputations as the actions of the named individual can be reported to a wide social network and affect that individual’s social standing
49
What is the consequence of language and kinship terms for social organization?
These allow for the formation of tribes, allowing large numbers of small groups to form very large social networks that develop cultural identities.
50
Which of the modern online services relies heavily on reputation?
A. Amazon B. Ebay, C. AirB& B
51
What is aneuploidy?
Deviation from normal chromosome numbers
52
Why were bacteria and protozoa discovered long before viruses?
Because viruses are sub-cellular parasites that cannot be seen by light microscopy
53
What is Koch’s postulate?
The notion that proof for pathogenesis by an agent requires that The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms. The microorganism must be isolated from a diseased organism and grown in pure culture. The cultured microorganism should cause disease when introduced into a healthy organism. The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.
54
List four different types of host defenses
Mucus barrierSkinAntimicrobial toxinsImmune cells
55
What is horror autotoxicus?
The horror of having one’s own powerful immune system unleashed against oneself
56
How much larger is a human macrophage than a bacterium?
4 to 40 times larger.
57
How does the macrophage recognize the bacteria?
By using innate immune receptors that recognize pathogen associated molecular patterns (PAMPs).
58
How thick is human skin?
around 2 mm.
59
What is the total surface of the human skin?
2 square meters without the folds, 25 square meters with.
60
What is mucus made of?
Mucus is a hydrated biogel consisting mostly of hydrated, highly glycosylated mucin glycoproteins but also salts and anti-microbial proteins.
61
What is the BBB (blood brain barrier)
A specially tight layer inside all the blood vessels in and around the brain
62
What kind of information does the immune system process?
Molecular information about self and non-self, consisting of composition and shape of molecules and the patterns these form.
63
List two cell types in the body that lose their genomes as they mature:
RBC
platelets
lens cells of the eye
64
List three similarities between our immune system and the brain.
Similar number of cellslong development after birthprocess information
65
What are innate immune receptors?
Proteins made by a host organism (germ line encoded, even in absence of immunization) that recognize molecular patterns on potential pathogens and parasites.
66
How does the rich diversity of alleles at many of the genes encoding innate immune receptors become apparent?
Individual humans can react very differently to the same pathogens.
67
How can liquid blood rapidly form a clot?
Blood is super charged with proteins that can react to contact with oxygen and form mesh works of fibers that can crosslink and entrap platelets, thus forming a clot.
68
Horse shoe crabs and other invertebrates lack an adaptive immune system. How do these animals protect themselves against infection?
Their innate immune systems produce protective proteins that recognize bacterial molecules.
69
What does clonal selection in the immune system refer to?
B-cells that make antibodies which bind antigens well, are allowed to replicate as clones, rapidly increasing the fraction of these B-cells over other, that fail to produce such antibodies.
70
How does the adaptive immune system prevent cells from reacting against self?
Developing immune cells that recognize self too strongly are forced to undergo apoptosis.(controlled cell death).
71
Which mechanism is more important in the somatic evolution of B- and Tcells, negative selection our positive selection?
Positive selection
72
How many protein chains make up a single antibody?
Four, two light and two heavy chains.
73
Give three cell types involved in innate immunity and three involved in innate immunity.
Innate: Neutrophil, Macrophage, Basophil
adaptive: B-cell, T-cell, T-helper cell.
74
what is the difference between MHC and HLA?
HLA is the human MHC.
75
How does human breast milk improve infant health?
It contains prebiotics and that help the infant gut be colonized by the right bacteria, probiotics in the form of bacteria, and it contains maternal antibodies that attenuate infections in the infant, and it modulates infant immune development.
76
What does SAMP stand for?
Self associated molecular patterns.
77
Can you name four autoimmune diseases:
rheumathoid arthritis: self attack on joints
multiple sclerosis: self attack on central nervous system
type 1 diabetes: self attack on pancreatic islet cells that secrete insulin
inflammatory bowel disease: self attack on gut tissue and or associated microbes
78
What is the concept of friendly fire in immune responses?
Immune responses can result in damage to the “self”, tissues or processes of our own bodies.
79
what is a monoclonal antibody?
A specific antibody made by one clone of B-cells (these can be isolated and the mass-produced by introducing the DNA sequence encoding this specific antibody into a cell line)
80
What is an example of a behavioral defense against infection in primates?
Grooming behavior, often reciprocal.
81
List 2 examples each of viral, bacterial, fungal, protozoan, helminth and prion caused diseases:
viral: polio and flu
bacterial: gonorrhoea and TB
fungal: candidiasis & valley fever
protozoal: malaria and sleeping sickness
helminthal: schistosomiasis & elephantiasis
prion: Kuru and Creutzfeldt Jakobs.
82
What is the generation time of viruses, bacteria, parasitic worms and humans respectively?
viruses: minutes
bacteria: hours
worms: weeks
humans: decades.
83
What two key features allow most pathogens to evolve more rapidly than their hosts?
Rapid generation time and high mutation rates.
84
Which pathogens ahem the smallest genomes?
Viruses
85
How can sex allow more slowly evolving hosts to survive in the face of rapidly evolving pathogens?
The shuffling of genetic material via recombination between chromosomes generates novel combinations each generation.
86
How does meiosis differ from regular cell division?
Meiosis (reduction division), involves not just the doubling of DNA, but also the recombination of chromosomes and the halving of the DNA content in the resulting sex cells
87
What is the two-fold cost of sex?
Sexually reproducing populations require twice as many individuals for the same number of reproductive events.
88
Which kind of reproduction allows novel mutations to spread more rapidly, sexual or asexual reproduction?
Sexually reproducing populations.
89
Can you think of an example of viral sex?
Viruses can have segmented genome (influenza A) and co-infection of two different viruses can lead to recombined viral progeny.
90
What is a molecular polymorphism and give an example.
Inherited molecular variation where at lest 1% of the population differs from the rest, e.g. ABO histo-blood groups.
91
What does “secretor” mean in the context of ABO blood groups?
Most people also produce the ABO antigens (glycans) on their secretions, a minority of people only produce them within their blood vasculature (non secretors).
92
What kind of molecular receptors are used by Norovirus (infamously knowns a “cruise ship viruses”)?
ABO antigens (glycans).
93
How is infection by an enveloped virus like a nano-transplantation?
Enveloped viruses are wrapped (enveloped) in the cell membrane of the host in which they were produced. In a new host, this can make them antigenic.
94
What type of infections are influenced by ABO blood groups an affect disease susceptibility?
Viral, bacterial, protozoan, fungal and helminthic infections!
95
How can herd immunity protect susceptible individuals in a population?
If the fraction of immunized individuals is high enough (70 to 90% depending on pathogen), the few susceptible individuals will be shielded by immune individuals.
96
What is hemolytic disease of the newborn?
A life-threatening condition where a baby is born with maternal antibodies against its own blood.
97
What is the reason that glycans are massively involved in infection and immunity?
This class of biomolecule is abundant at the “molecular frontier” of cells and tissues.
98
Sialic acids are exploited by many important pathogens fro invasion and immune evasion. How come, vertebrate hosts did not evolve away from using sialic acids on their cells?
Vertebrates have become critically dependent on using sialic acids for development, they cannot afford to abolish these molecules.
99
How can mucins be resistant to digestion?
The tightly arranged glycans make it impossible for protease enzymes to digest the core protein.
100
What is the difference between Neu5Ac sialic acid found in all vertebrate and the animal Neu5Gc sialic acid lost in the human lineage?
The presence of one additional oxygen atom in the non-human Neu5Gc.
101
What prevents a virus that uses the alphaGal antigen as a receptor from infecting humans?
The complete absence of Alpha Gal on human cells!
102
What makes pig kidneys super antigenic in a human xenotransplant recipient?
The presence of alpha Gal on all pig cells combined with his levels of pre-existing anti-alphaGal antibodies in all humans.
103
What is the difference between horizontal and vertical transmission of a pathogen?
horizontal is across a population via infection, vertical is infection from parent to offspring.
104
How can infection by multiple strains of a pathogen lad to increase virulence?
It can lead to competition between strains, which can result in higher damage to the host.
105
How does the malaria parasite manipulate mosquito behavior in its favor?
Plasmodium causes mosquitoes to take blood meals from more different hosts, increasing the rate of infection of humans by a single mosquito.
106
Why do waterborne diseases tend to be rather virulent (cause very severe disease)?
The pathogen is more likely to be passed on if the patient has diarrhea and vomits, ideally near water sources…..the patient does not need to walk around or look attractive to infect others.
107
What prevents a virus that uses Neu5Gc sialic antigen as a receptor from infecting humans?
The complete absence Neu5Gc sialic acid on human cells!
108
What is the effect of multiple infection on pathogen virulence?
Competition between co-infecting pathogens can increase virulence of each.
109
How can increased contact with fresh water change the pathogen regime of human populations?
Through increased exposure to waterborne diseases including schistosomiasis (=Bilharziosis), guinea worm, leptospirosis etc.
110
Why is schistosomiasis widespread in East Asia?
Paddy rice agriculture forces farmers into long hours of work standing in water.
111
How could the use of a home bases contribute to disease load?
It likely increased the chances of infection due to shared space and accumulation of bodily waste in a limited area.
112
What would a larger number of prey animals contribute to changed pathogen load?
Each species carries its own collection of microbes, by handling the carcasses of more different species, human ancestors would have samples larger number of pathogens.
113
What made hominins good at obtaining bone marrow form the long bones of large animals?
Their cooperation in chasing away other predators or scavengers (hyenas and lions) and their use of stone tools to get access to fresh marrow and brain tissue after breaking the bones and skulls.
114
List five ways in which fire massively changed the opportunities of humans before agriculture.
protection from predators, cooking, lighting, changing landscapes, harvesting honey.
115
How might the regular use and fire and tuberculosis be related?
Fire brings people together and damages lungs.
116
How could trade have affected the history of human diseases?
Repeated long-distance contacts and exchanges could have spread infectious diseases.
117
What novel risk did agriculture bring for people?
Famine, warfare, taxation, social inequality.
118
What is the neolithic?
The period encompassing the last 12 ,000 years since humans have become sedentary, started farming/herding and developed complex societies.
119
Farming made many new human endeavors possible, but it also ushered in or amplified the 7 Ps. List the seven Ps:
Poverty
Poor Health
Plunder
Politics
Power Differentials
Pathogens
Parasites
120
How could larger cities have contributed to disease burden?
High density of people, better for spread of infectious disease likely to cause more social stresswater supply very prone to getting infectedcities rely on trade, trade can bring disease.
121
What was the contrast in animal domestication between the Old World (Asia and Europe) and the New World (the Americas)?
Far fewer animals species domesticated in the New World: dogs arrive with first waves from Asia, turkey and lama/alpaca, and guinea pig.
122
What is the disease called pellagra?
A vitamin deficiency stemming from the lack of adequate preparation of corn (lack of nixtamalization).
123
How is it possible that doctors in 1840s were not aware of bacterial infections?
It predated the notion of “microbes” or “germs”, only visible by microscopes and totally overlooked by all medical traditions
124
Name three ways in which industrial development can change disease burden:
Pollution, Urbanization, Social injustice.
125
How could number of menstrual cycles be affecting female cancer risk?
Hormonal fluctuation and resulting tissue remodeling in the bread and uterus associated with each cycle introduce opportunity for cancer causing mutations to occur.
126
What is the evidence that human breastmilk contains brain food?
The brains of breast fed babies differ biochemically from those of formula fed babies.
127
list two military technologies that have caused long term health sequelae in civilian populations
Nuclear bombs and defoliating agents (dioxin).
128
How does paternal age affect the risk for genetic disease in a child?
Most mutations happen in the father and more happen the older he is.
129
What is iatrogenic disease?
A disease caused by medical professionals.
130
Give an example of improved technology that causes disease.
Tampons with extremely good absorbance and Toxic Shock Syndrome.
131
What is the jist of the hygiene hypothesis?
Improved hygiene, frequent use of antibiotics, and vaccination deprives children of contact with microbes and shifts the balance of the immune system towards becoming allergy/ prone to auto-immune reactions.
132
List for areas where the human footprint is particularly measurable on the planet.
East Asia, South Asia, Europe, and Eastern North America
133
Why is Africa the only continent that still has such large numbers of wild animals?
African animals evolved with humans, they are people smart. Large animal on all other continents were taken by surprise when these bipedal primates with their efficient hunting tools arrived, many of them died out.
134
What is the size of a virus?
~ 100 nanometers or 10^-7
135
How do logging roads contribute to increased contact between human and wildlife?
Once in place, local humans who often are desperate to find new livelihoods follow these new road and establish camps along them and then hunt for animal proteins in areas that had very little human wild life contact.
136
How could shipments of car tires affect global disease?
Rain water in old car tires allow mosquitoes to breed and provide unintended transport of novel mosquito species across continents.
137
Why was on of the many negative effects of the transatlantic slave trade on global disease?
African infectious disease and their mosquito vector species arrived in the Americas.
138
What technology has made the discovery of new viruses much easier?
Molecular detection (PCR, next generation sequencing, allowing the detection of viruses in primary samples without prior culture to amplify virus numbers).
139
What do the letter H and N in the names of different influenza A viruses stand for?
Hemagglutinin for binding to cells and Neuraminidase for cutting off sialic acid from cells or muffins.
140
What factor could cause very closely related species such a s humans and chimpanzees to have very different susceptibility to infection by a given virus?
Changes in nature and/or distribution of cell surface molecules (proteins, glycans or lipids).
141
How can mucus impact infection risk by a virus?
The mucus can contain receptor molecules for viruses and act as a decoy/smokescreen.
142
Why is it totally unrealistic to eradicate influenza viruses?
They have a gigantic reservoir in many species of wild water birds that migrate across the planet.
143
Which factors helped spark the HIV/AIDS pandemic?
Colonialism, mass migration, urban centers including sex workers, intercontinental medical aid, blood commerce, sex tourism, IV drug use.
144
How could logging roads affect emerging diseases?
Local people and immigrants use the road to access new areas where they farm and hunt for bushmeat.
145
Why are bats so important for monitoring emerging viral diseases?
Their high mobility and resistance to viruses make them ideal reservoirs.
146
List five major classes of human pathogens?
Viruses, bacteria, protozoans, helminths and fungi & prions.
147
List three types of different anti-viral vaccine with regard to how these are produced and delivered to humans.
Inactivated, attenuated live, subunit, genetic, viral vector.
148
List two components each of the cellular and humoral immune system.
B-cells and macrophages, antibodies and complement.
149
What do you call a disease in non-human animals caused by a human pathogen?
An Anthroponosis.
150
Which type of multicellular animals seem to be free from cancer?
Organisms with simple or aggregative muticellularity (e.g. sponges).
151
What is the difference between a neoplasm (neoplasia) and cancer?
Neoplasia is uncontrolled cell growth that can be benign, cancer includes major genetic accidents and eventually metastasis (dispersal of cancer cells through the body).
152
What are the five foundations of multicellularity?
Proliferation inhibition, controlled cell death, extracellular environment, division of labor, resource allocation.
153
What is an important trade-off faced by cancerous cells?
Proliferation via rapid cell division, versus migration and mobility to invade the body.
154
Why can we condor the body of an individual human a clone?
All body cells derive from the same fertilized egg and share the same genome
155
Give two examples each of solid tumors and liquid tumors?
Solid: Carcinoma and Sarcoma
liquid: Leukemia and Lymphoma.
156
How can different cell types be generated from the identical genome shared by all cells found in an individual?
Through differential gene expression, with different subsets of all 22,000 genes expressed to different degrees, in different combinations, and at different times.
157
Name three cell types in mammals that have evolved to invade the body of another individual:
Sperm, trophoblast (extra-villous), transmissible tumors in carnivores
158
What are carcinomas, sarcomas and leukemia cancers?
Epithelial, muscle or blood cll cancers.
159
Why is cancer not really a single disease?
Many different causes, different cancers have different properties and vary in how rapidly they cause death.
160
Give three environmental causes for DNA damage.
Chemical substances, radiation, viruses.
161
How could a virus cause cancer?
Viruses can manipulate gene expression and “immortalize infected cells;” viruses can cause mutations by inserting their own DNA into the host cell genome.
162
What is the difference between a primary cancer cell and a metastatic cancer cell?
The primary cancer cell arises in a particular tissue, the metastatic cancer cell has migrated to other sites in the body.
163
Why are tissues with rapidly dividing cells more prone to cancer?
Each cell division requires de replication of the cell’s entire genome, this is an opportunity for replication errors (=mutations) to occur.
164
Do Japanese Hawaiians have colon cancer rates more similar to Hawaiians or to Japanese in Japan?
Hawaiians.
165
What are three reasons that mammals are especially prone to cancers?
Complex multicellularity, placental, long-lived.
166
What are two parallels between fetal tissues and cancerous tissues?
1. invasive tissue
2. remodeling of the blood vessels
3. immune suppression
167
Why do tumors larger than a certain size require new blood vessels?
The inner part of larger tumors cannot survive without gas exchange and nutrients.
168
What is Antagonistic Pleiotropy?
Opposite effects of the same gene early and late in life
169
What are onco-fetal antigens?
Molecules that appear commonly on fetal tissues and certain cancers.
170
What is an antigen?
A molecule that can be recognized by an antibody (immunoglobulin)
171
What happens to the glycocalyx of cancers?
It is alway altered from that of healthy cells.
172
Why is “oncogene” not a very logical term?
Natural selection would not favor genes that cause cancers. Oncogenes have other functions important to the organism, but if mutated or not regulated properly, they can cause, or contribute to cancer.
173
How could a protein guard the genome?
By stabilizing DNA during replication and/or recruiting DNA repair mechanisms
174
Name three important behavioral factors that strongly affect cancer risk.
Diet, tobacco use, and UV exposure
175
What epigenetic modifications could influence cancer risk?
DNA methylationHistone modifications Non-coding RNA.
176
What is cancer immunoediting?
The process by which the body’s immune system shapes cancer and leads to either elimination, equilibrium or escape (selection for variants cancer cells that escape immune defenses).
177
What is CAR T-cell therapy?
Immune therapy against cancer, where the patients own T-cells are harvested, transformed outside the body to express a cancer specific receptor and then rein fused into the patient to target the cancer.
178
What is the evidence that our ancestors were upright by over 5 million years ago?
Fossil skeleton of ape-like species with skeletal adaptation to upright posture (foramen magnum, pelvic and leg bones).
179
Name three conditions that represent costly consequences of bipedalism in humans.
Low back pain, obstetrics, hemorrhoids
180
What is cephalon-pelvic disproportion?
Mismatch between head size of the baby and hip size of the mother
181
What are the major differences between birth process in humans and the related great apes?
Humans have much higher variation in gestation time, much longer duration of labor, and birth is associated with much higher levels of pain.
182
What is the notion of an obstetrical dilemma?
The idea that human mother balance the requirement of bipedality with those of birthing a. super large headed baby.
183
What is the difference between endocannibalism and exocannibalsim?
The hundreds of thousands of years that our species spent spent living as foraging small scale communities.
184
What is meant by the Environment of Evolutionary Adaptation EEA?
The hundreds of thousands of years that our species spent spent living as foraging small scale communities.
185
What is the modal (most common among adults) age of death in living hunter gatherer societies?
70 plus years!
186
If life expectancy is around 35 years for most hunter gatherers, how can there be substantial numbers of 70 year olds in those societies?
Very high infant mortality brings down the life expectancy.
187
Why is Omran’s concept of the earliest stage of epidemiology as one of “pestilence and famine” not necessarily correct?
Because prior to agriculture in the last 10 thousand year low-density hunter gatherer life included: few famines, balanced nutrition, long inter-birth intervals, lower threats of widespread epidemics
188
What is meant by double burden of disease?
Societies where both, communicable (infectious) disease and disease caused by modern lifestyle cooccur!
189
How could a bacterial infection transmitted by skin contact in South America have evolved into a STI like syphilis?
Sexual exploitation and violence at the hands of the Spanish conquistadores could have selected for sexually transmitted variants that benefit from lesions on genitals fro transmission.
190
How could TB in pre-columbine South American skeleton be more closely related too TB in seals than any other TB strains?
Intense coastal hunting for seals by paleoamericans could have exposed them to this new strain.
191
How could scientists determine what caused the epidemic of Cocolitli?
Ancient DNA studies of skeletons in mass graves dated to the year of the outbreak.
192
What did the Justinian plague of the 6th century, the Black plague in the 14th century and the Hongkong plague of 1890s have in common?
they were all caused by the bacterium Yersinia pestis.
193
How can the plague be thought of as a spill over event?
The pathogen lives in wild rodent (marmots, ground squirrels) and trade with their fur led to the importation of the pathogen to trading cities around the Mediterranean.
194
Name three social consequences of the Black Death in the 14th century?
break down social order, pogroms (violent upheavals) against local Jewish populations, religious upheaval (protestant reformation).
195
How can scientists test the effect of a genetic mutation involve red in. immune cell activation against the plague?
By testing immune cells with different genotypes with regard to their activation to plague bacteria in a dish in the lab.
196
Is infection by the plague strictly transmitted by fleas?
No the plague can become pneumonic, i.e. transmitted directly from one human to the next (airborne).
197
What is a haplotype in genetics?
A unique combination of genetic variants (alleles) along the same string of DNA on a given chromosome.
198
Does Neanderthal DNA in modern humans protect from or put people at higher risk from COVID?
Both, depending on which chromosome the DNA is on.
199
How can scientists get information about Neanderthal microbiome?
By extracting ancient DNA from dental calculus of Neanderthal fossils s old as 40,000 years.
200
Which non-human species has been observed actively spreading fire?
Black kites in Australia.
201
What do some Australian aboriginal cultures believe black kites taught humans?
Hunting with fire.
202
What are three advantages of burning landscapes?
Hunting is easier, travel is easier, and new grass attracts prey
203
What is especially precious about evidence for fire in caves?
One can safely rule out natural fires from lightning strikes.
204
Where can paleoclimate researchers find modified glucose from biomass fires tens of thousand of years ago?
Sediment samples from ocean drill cores.
205
What can honey guide genetics teach us about human fire use?
The ancient divergence between bird lineages that do or do not interact with humans, point to the deep age (~2 my) of fire use by humans.
206
Where are people still most affected from indoor fire smoke inhalation?
Africa and India, South East Asia.
207
Why do certain plants make nicotine?
It is a natural pesticide against insect herbivores.
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How could a natural pesticide made by plants cause addiction in humans?
Nicotine “hacks the brain” where it interacts with special receptors. Nicotine use rapidly creates addiction as the brain habituates to this effect and starts feeling g bad if nicotine is not provided.
209
What PR trick was used to widen the tobacco market after WWI?
Smoking was heavily advertised to women.
210
How could cigarette smoke harm a child before it is born?
Compounds from cigarette smoke can make it into the bloodstream of the fetus and harm brain development and cause alteration of chromatin.
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What are the three smokes?
Biomass burning, Tobacco, air pollution by industry and traffic.
212
What is anthracosis?
Black lung disease/soot accumulation in lungs.
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How could food preparation contribute to disease risk?
Smoke from indoor stoves or fireplaces & Cooking, frying and baking can generate harmful toxins.
214
What are the parallels between Maillard reaction products and advanced glycation end products (AGE)?
Both are products of reactions between sugars and proteins.
215
Why are PAH mutagenic/carcinogenic?
These multi-ringed molecules react with DNA which can cause mutations during DNA replication.
216
What are he effects of poly aromatic hydrocarbon (PAH) on brain anatomy in humans?
Reduction of brain white matter (connections between neurons).
217
Name two chemicals not related to fire and smoke that bioaccumulate in the food chain.
Polychlorinated biphenyls (PCB) and methyl Mercury.
218
What are demonstrated effects of micro plastics in lab mice?
Lower sperm count in males and lower body weight of pups sired by these males
219
What species were transposons discovered in?
Maize
220
Why could the activity of a transposon be dangerous for organism in which it happen?
genomic instability/mutation/ disruption of gene function
221
What is likely wrong about the notion of “junk DNA”?
Much of the non-coding DNA seems to have functions in the genome.
222
Does the human genome contain more genes or more transposable elements?
More TEs.
223
What is the genome of the pufferfish so much smaller than that of most other vertebrates?
The ancestors of the pufferfish purged transposable elements from their genome.
224
What makes a retrovirus a retrovirus?
Its genome encodes an enzyme that can “back-transcribe” RNA into DNA.
225
What is an endogenous retrovirus?
A retrovirus that has been incorporated in the host genome.
226
Give an example of a “domesticated endogenous retrovirus”.
HERV9 in Tp63 in spermatogenesis, Syncytin 1 and 2 i trophoblast/placenta.
227
How can our genomes defend themselves against molecular parasites such as transposons?
By inactivating the chromatin in which the transposons are located.
228
How could there be an “arms race” between selfish DNA and our genomes?
Genomes have to evolve defenses against rampant and disruptive transposon activity, but successful transposons evolve ways around d these defenses.
229
What fraction of the human genome consists of retrotransposons?
Almost half!
230
How have animal immune systems evolved by use of transposons?
Different animal lineages have recruited transposon DNA to generate diversity used in their immune systems.
231
Which cell types in the human body activate recombination activating genes (RAGs)?
B-cells and T-cells of the immune system.
232
Why would a bacterial enzyme that recognizes a certain DNA sequence be able to cut the genome of primates into thousands of chunks?
If the recognized sequence is identical to sequence of an Alu element, the enzyme would cut DNA wherever one of these thousands of transposons are in the genome.
233
Are human and chimpanzee genomes the same size?
No, chimpanzee genomes are slightly larger due to accumulated repetitive sequences
234
How are transposons involved in neuronal diversity?
During neurogenesis, transposon activity is increased, generating differences in the genomes of neighboring neurons.
235
Do we humans have transposable elements that do not exist in the apes?
Yes, a subset of young Alu elements for example, have only replicated and inserted after our last common ancestor with apes.
236
Give an example of a human disease caused by an Alu element:
Neurofribromatosis.
237
How could transposable elements affect ape evolution?
TE such as the LAVA TE in gibbons causes massive chromosome rearrangements. This can potentially cause reproductive incompatibility and with it speciation.
238
How can a mutation caused by an Alu elements in one enzyme result in an over-all change of most cell surfaces?
If the enzyme is a glycan modifying enzyme, it would affect millions of glycan chains on most cells.
239
Why is Rett’s Syndrome only observed in females?
The X-linked mutation is lethal is males.
240
Is the human body a perfect clone of the fertilized egg cell?
No, certain tissue have somatic mutations (often associated with transposable elements), especially neurons.
241
How could xenotransplantation represent health risks for the general human population?
By allowing animal viruses to infect the immune suppressed human patient, to adapt and then to infect other healthy humans.
242
Give an example of a “domesticated virus”.
Syncytin 1 and 2 and suppressyn on human trophoblast.
243
Are humans the only mammals species that “domesticated” an endogenous virus to evolve a better placenta?
No several other mammal species have independently done so.
244
Describe the evolutionary invention of milk:
Ancestral mammals evolved milk as a nutritious food for their young from modified sweat glands. They used a modified anti-bacterial enzyme to evolve a lactose synthesizing enzyme, making a sugar (disaccharide lactose) that is easy to share between mother and infant but difficult to “steal” by most microbes.
245
What is evolutionary bricolage (François Jacob)?
“Evolutionary tinkering”: novelty can be pieced together from different existing features.
246
What prevents a virus that uses the alpha-Gal antigen as a receptor from infecting humans?
Humans completely lack the alpha-Gal antigen on their cells.
247
How can infection by multiple strains of a pathogen lead to increased virulence?
Competition between strains can cause pathogens to become more damaging to the host.
248
What triggers human immune systems to form circulating antibodies to alpha Gal and ABO?
The presence of alpha Gal and ABO sugar chains (glycans) on bacteria of our normal gut microbiome.
249
What is alpha Gal syndrome?
An acute immune reaction to a meal heavy with red meat after having been stung by a lone star tick.
250
What is the key concept of the hygiene hypothesis?
Improved hygiene, frequent use of antibiotics, and vaccination deprives children of contact with microbes and shifts the balance of the immune system towards becoming allergy/prone to auto-immune reactions.
251
Which pathogen was first believed to cause the flu during the 1918 pandemic?
The bacterium Haemophilus influenza, people were not aware of the virus!
252
What is the role of elf cilia in our airways?
They are responsible for moving mucus along and dispatching potential infectious agents caught in the mucus layer.
253
What is unusual about the genome of the Influenza A virus?
Its RNA genome is segmented into 8 pieces.
254
How would the reuse of glass syringes lead to serial passaging?
Contaminated body fluids from the first person injected would then be injected into the next person on whom the unsterilized syringe is used.
255
Why do so many viral diseases have origins in African primates?
Humans are African primates, which greatly facilitates cross-over infections.
256
What type of cancers can safely be diagnosed in fossils as old as Homo erectus from over 1 million years ago?
Bone cancers including osteosarcomas.
257
Why can we compare the body of an individual human a clone?
All body cells derive from the same fertilized egg and share the same genome.
258
What is mistaken about the concept of an oncogene?
Genes do not evolve to cause cancer, oncogenes are critical genes, that are associated with cancer when they mutate/malfunction.
259
Which two types of cancer are the most sexually dimorphic?
Breast and prostate cancer
260
Give an example each of a cancer either high or very low survival rate?
High: prostate
Low: pancreatic
261
What is the difference between antibodies and antigens?
Antibodies are immune molecules that can target antigens (molecules that cause immune reactions).
262
What is meant by p53 being a “guardian of the genome”?
p53 proteins can protect against DNA damage, hypoxia, telomere shrinkage and oxidative stress.
263
How is signal transduction involved in cancer?
Mutations in key signaling molecules (cytoplasmic proteins) can dysregulate cell division and/or programmed cell death.
264
How do human and chimpanzee prenatal brain growth rate differ?
Human brain growth rate is constant but chimpanzee brain growth rate starts slowing down mid gestation
265
What is cephalo-pelvic disproportion?
Mismatch between head size of the baby and hip size of the mother.
266
What kind of adaptation to difficult birth are apparent in the newborn skull?
Unfused bone plates allowing the head to change shape during very tight brith!
267
Name an advantage and downside for red meat consumption.
Nutritious, great source of protein and iron, negative impact on cancer and atherosclerosis.
268
What came first, increased meat consumption or the use of fire?
Increased meat consumption
269
Name three major differences between traditional forager diets and modern diets.
Foraging diets were more varied, lower in calories and much richer in plant fiber.
270
Explain the concept of Environment of Evolutionary Adaptation.
The prevailing environment in the 200,000 plus years before the beginning of settlement and agriculture that shape much of human biology
271
Name three well-studied foraging societies
Khoisan, Ache and Hadza
272
Explain the concept of epidemiological transition.
The shift from high mortality due to infections to death by chronic and degenerative diseases.
273
What is a phage?
A virus that infects a bacterium.
274
What can honey guide bird genetics teach us about human fire use?
The ancient divergence between bird lineages that do or do not interact with humans, point to the deep age (~2 my) of fire use by humans.
275
How can Beirut, Libanon have such higher levels of medium sized particle pollution in the air the n Los Angeles, US?
Many more diesel engines and much less stringent air quality control laws.
276
What is a transposon?
A piece of DNA that can make additional copies of itself and paste the copies back into the genome.
277
What is the difference between LINE and SINE elements?
LINEs are much longer and can encode the enzyme required to copy themselves, SINEs are shorter and rely on the copying machinery of LINEs
278
Give an example of a human disease caused by an activated human endogenous retrovirus:
Schizophrenia
279
How could human endogenous retroviruses cause disease?
In multiple ways, by disrupting gene expression, by triggering antiviral protection systems, by driving inflammation.
280
Are humans the only mammals species that “domesticated” an endogenous virus to evolve a better placenta?.
No several other mammal species have independently done so.
