exam 2 bio

a property of all living things

- reproduces its own kind. - takes in, coverts, and expels energy. - complex, but well-ordered, structure. - composed of one or more cells. - responds to the environment. - populations evolve over time.

not a property of all living things

- requires another individual to reproduce - composed of many cells - individuals evolve over time - eats other organisms to gain energy

which of the following statements are false regarding bias in DNA profiling?

-DNA profiling is an ineffective tool for identifying individuals. -DNA profiling is flawed and should not be used as evidence.

str analysis

1. dna isolation 2. pcr 3. gel electrophoresis - long fragment at top, short go to the bottom

steps in polymerase chain reaction (pcr)

1. start with a sample of double-stranded dna 2. heat sample to separate dna strands 3. dna polymerase duplicates dna strand 4. cool sample to allow dna double helices to form

early analysis by the innocence project found that around ___ of wrongly convicted individuals were wrongly convicted by hair analysis

25%

if thymine (T) makes up 20% of the bases in a DNA double helix, what percentage of the bases is guanine (G)?

30%

if one polynucleutide strand of DNA has ACTTGACTAGCTA as its sequence of bases, what would be the sequence of bases on the opposite strand?

TGAACTGATCGAT

which of the following can be found in bacteria, but not viruses?

a cell membrane

in the projected video showing the growth of bacteria, why did the bacteria grow up to the edge of the area with antibiotics, pause, then continue to grow across the area with antibiotics?

a few bacteria experienced random mutations in their DNA, which allowed some of them to grow even though antibiotics were present.

natural selection is best described as..

a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations

which of the following is an orphan gene?

a gene found only in the southern two-toed sloth, Cholepus didactylus.

pathogen is ____

a name given only to bacteria that. cause serious illnesses in humans

which of the following is true?

a person vaccinated for measles can get the disease, though it is not likely.

in the immune response, the end goal is to disable or kill pathogens that invade the body. But first, antibody proteins or proteins in immune cell membranes must recognize and bind to invaders. this is a challenge, given the vast diversity of pathogens that can infect us. To meet this challenge, immune proteins _____.

are diverse: each immune protein can bind to only one or a few pathogens, but immune proteins are tremendously diverse, so the system is likely to possess a "match" to nearly any pathogen

over time, bacteria have become increasingly resistant to antibiotics. Which of the following best explains this in terms of natural selection?

bacteria that happen to have natural resistance to antibiotics survived and reproduced.

a _____ is a virus that specifically infects bacteria

bacteriophage

let's say that after many generations most grizzly bears have fur that is not very dense. Based on the correct answer from above, what do you think would happen if the Earth experienced global cooling and slipped into and ice age?

bears with dense fur will become more common in the population

when a B cell binds to a virus or other pathogen, it _____.

becomes activated, divides rapidly, and thereby mounts a specialized response against the pathogen.

clonal selection (look at diagram in post-assignment 5)

begins with first exposure to antigen - stimulates production of first clone ; first clone consists of effector cells and memory cells - effector cells include B cells, helper T cells, cytotoxic T cells - B cells and helper T cells result in humoral immune response and cell-mediated immune response

____ is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information.

dna

correct the following; rna > protein > dna

dna > rna > protein

flow of genetic info in a cell

dna > transcription > rna > translation > protein

why is dna analysis more sensitive than microscopic hair analysis

dna provides more targets that can be distinguished between two individuals

silent mutation

does not change an amino acid

place the following steps of DNA replication in the proper order: DNA fragments are fused together; double helix is pulled apart; new strands of DNA are synthesized.

double helix is pulled apart, new strands of DNA are synthesized, and DNA fragments are fused together

after DNA replication, __________

each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand

imagine that four people are infected with HIV from a common source (an infected blood sample). Initially, the patients' HIV populations are genetically identical. By the time they develop full-blown AIDS, how would the viral populations of the fourpatients compare?

each patient's viral population would be unique, specifically adapted to deal with—and overcome—his or her unique immune system responses.

in the video, what does the UK's Chief Medical Officer suggest for promoting the development of new antibiotics?

encouraging big pharmaceutical companies to start investing again in new drug research and developmen

clinical trials for the development of new drugs have focused almost exclusively on their effects on people of:

european ancestry

studies associating common genetic variation with specific diseases have focused almost exclusively on people of:

european ancestry

______ defenses are always at the ready and are the same whether a particular infectious agent has been encountered before or not

external

t or f? standard str analysis of dna sample from a crime scene and dna from a suspect shows matches at four sites. the suspect is guilty

false

which of the following results in the creation of gene families?

gene duplication

as proposed by Darwin, what sorts of traits are favored by natural selection?

heritable traits that help individuals survive and reproduce more successfully than others in the same population.

what does "fitness" mean when speaking in terms of evolution?

how many offspring an individual produces

the _____ system is a collection of cells and organs that protect an organisms body from agents that can cause disease

immune

let's connect global climate change with evolution. How might an increase in global temperatures result in most grizzly bears having fur that is less dense in the future?

in any population of bears, some individuals have thick fur, some have thin fur, and some are in between. As temperatures increase with the passage of time, the survival of bears with thin fur will increase, and the number of bears in the population with thick fur will decrease.

carcinogens

include cancer-causing factors

natural selection acts on ________, and ________ evolve.

individuals, populations

types of frameshift mutations

insertion and deletions

point mutations

involving a single nucleotide change

frameshift mutations

involving multiple nucleotides

gel electrophoresis separates dna fragments according to their ____.

length

the _____ is a viral life cycle in which the virus inserts its genome into the genome of its host, where it may remain dormant for long periods

lysogenic cycle

the _____ is a viral life cycle that results in bursting of the host cell

lytic cycle

the rna molecule, which exits the nucleus, is a specifc kind of rna called ___

mRNA

what has yet to be shown? cells with synthetic nucleotides ____

make new proteins

some viral diseases are dangerous only when a person is infected for the first time; subsequent infections produce only mild symptoms or go entirely unnoticed. This pattern can be explained by the action of _____.

memory cells that trigger a secondary immune response

a particular antibiotic kills 99% of a bacterial population. What will be the result of the continued application of this antibiotic?

over time, the antibiotic will become less effective at killing the bacteria.

a ___ is an agent in the environment that has the potential to cause disease

pathogen

____ describes the process of engulfing and destroying a foreign particle

phagocytosis

overall, a molecule of DNA has a negative charge. Which component of DNA gives it this charge?

phosphate group

evolution is changes in the frequency of genes in a gene pool. According to this definition what is the smallest biological unit that can evolve?

population - populations evolve, individuals cannot

helpful

probiotics, decomposers, nitrogen fixers

gene cloning is used to ___

produce large quantities of human proteins

a ____ is a viral genome that has inserted itself into he genome of its host

prophage

which of the following is true? protein coding

protein-coding genes make up far less of the human genome than noncoding DNA.

once it exits the nucleus via the nuclear pores, this molecule travels to a cellular organelle called the ____

ribosome

____ is used in all steps of protein synthesis and carries the genetic information of many viruses.

rna

if DNA directs the production of RNA, what does RNA make?

rna makes proteins

the enzyme that performs this process ic called ____

rna polymarase

food poisoning is often caused by a bacterium called ________.

salmonella

harmful

salmonella. pathogens, mrsa

types of point mutations

silent mutation, missense mutations, nonsense mutation

the introduction of smallpox to the Americas by Europeans in the colonial era devastated populations of native Americans. Now, however, very few people are vaccinated against the smallpox virus. Why?

smallpox virus has been eliminated from the Earth by vaccination of most of the people alive today.

what statement is true regarding bacteria?

some bacteria are pathogens and harmful to humans, whereas lots of bacteria are helpful to humans

antibodies are

specialized proteins that attach to pathogens and disable them or mark them for destruction by immune cells

Dan Krane proposes a solution to bias would be to blind the samples. What does blinding the samples refer to?

the identify of the individual the sample came from is kept unknown from the analyst.

following an injury to your hand, the injured area appears red and swollen. It feels painful and warm to the touch. What is the cause of these symptoms?

the inflammatory response

why is combination drug therapy for HIV/AIDS less likely to lead to resistance than single drug therapy?

the likelihood of one virus spontaneously mutating to be resistant to several different drugs at the same time is extremely small.

you have a child and decide to not have him vaccinated. Who is most likely to support you in this decision?

the national vaccine information center

zombie apocalypse wipes out entire population except 100 people who were gone during the time - despite an abundance of habitat, why will it be difficult for the human species to recover?

the reduced genetic diversity will make it difficult for the population to adapt to new diseases or other environmental changes.

what is the concern about using antibacterial and antimicrobial soaps?

the use of any chemical that kills bacteria can eventually lead to resistance to that chemical in the population of bacteria.

which of the following statements about viruses is FALSE?

the widespread use of antibiotics has led to resistant strains of viruses.

pcr s used to copy just a relatively small region of DNA, not the entire genome. How do researchers specifically target the region of interest?

they use two primers, each about 15 to 20 nucleotides long, that flank the region of interest

you have a young child. you can get them vaccinated for all of the following diseases except?

tonsilitis

the process of ____ creates a molecule of rna from a molecule of dna

transcription

there, the sequence of nucleotides on this molecule is used to create a molecule of protein through the process called _____

translation

t or f? just as variations among human genomes lead to differences in eye and hair color, different humans metabolize drugs differently depending on the make-up of their DNA.

true

what is the primary factor that has led to the lack of indigenous communities cooperating in genetic research?

use of indigenous genome data without the consent or knowledge of the people from whom the data were taken

which medication prevents viral infections by priming the immune system against a specific virus?

vaccine

although generally not considered to be alive, a ___ is studied alongside other microbes such as bacteria

virus

you are a biochemist and have been given a test tube containing a small amount of nucleic acid. You have been asked to determine whether it is DNA or RNA. Which of the following would be a characteristic that indicates RNA?

-presence of ribose, but no deoxyribose -presence of uracil, but no thymine

Dr. Fox is the founder of "IndiGenomics", which focuses on genetic research to improve minority health through:

-teducating indigenous communities on the potential use and misuse of genetic information -methods that respect indigenous knowledge -encouraging members of the community that is being studied to participate in that research

which three statements may correctly explain why the population size increases after time point C? (pre-assignment 6)

-the few drug-resistant bacteria in the population reproduced, quickly leading to a large drug- resistant population. -bacteria that acquired a mutation that conferred drug- resistance had a growth advantage over non-resistant bacteria. - between time points C and D, drug-resistant bacteria were reproducing faster than non-drug resistant bacteria were dying.

how are DNA and RNA different?

DNA contains the bases A, G, C, and T; RNA contains the bases A, G, C, and U

you work for Synthorx, creating synthetic DNA. You create a sequence on one strand of CTXAGGC. What is its complimentary strand?

GAYTCCG

suppose you were in charge of sending an unmanned space probe to a new planet in search of life. The probe would be able to collect and test samples and make observations, but the planet is too far away for the probe to be able to bring samples back to Earth. The probe is small and would only be able to run a few tests, so you want to pick a test for evidence of life that is broad enough to incorporate all forms of life as we know it. Which one of the following tests would be the best to use in this situation?

a test for the presence of cells that contain DNA

homeostasis is a living organism's

ability to maintain constant internal conditions even when environmental conditions change.

______ describes a set of defenses that is customized to each infectious agent, providing a stronger response when an agent has been encountered before

adaptive immunity

your cousin is a xenobiologist working to insert synthetic DNA into a virus with the goal of creating a vaccine for H.I.V. If she follows similar methods to those already used, which of the following will she need to aid her in this process?

algae gene

what is the condition called when your body's immune system overreacts to an otherwise harmless foreign particle?

allergy

which of the following correctly describes what the video referred to as a "microbial cure"?

antibiotics are used to kill all the infectious bacterias in a person

HIV has become an important source of mortality for humans. If AIDS persists as a major factor for humans for many generations in the future, natural selection theory predicts that _____.

any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time

the protein coat that surrounds the nucleic acid of a virus is called a _____

capsid

mutagens

caused by environmental factors

what is the definition of evolution?

change in the gene pool of a population from generation to generation

imagine a gene mutation creates a new color of hair in a population. What effect will this have on the population?

change the frequency (relative proportion) of hair colors in the population

you are a molecular biologist and wish to change the proteins that cells make. Which of the following should you do?

change the sequence of the nucleotides

nonsense mutations

changes an amino acid to a stop codon

missense mutations

changes one amino acid to another

____ are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.

chromosomes

the ____ system is a set of proteins that circulate in the blood, stimulating other defenses to help destroy an invader

complment

which of the following is NOT a characteristic of living things?

creating energy

mutations

defined as changes in the sequence of dna

dna profiling replaced an older technology for use in identifying suspects in crimes. What technology was commonly used by the FBI's Forensics Labs to identify unique characteristics of individuals prior to DNA profiling?

microscopic hair analysis

a dna profile examines dna from

multiple locations in the genome

we discussed antibiotic resistant bacteria in class last week. Which process of evolution most likely created the resitant varieties of bacteria? (I.e., what causes bacteria to become resistant to antibiotics?)

mutation

what is the most likely explanation for the changes in gene copies?

mutation

which of the following "five fingers" or mechanisms of evolution is the only process that consistently leads to organisms that are better adapted to their environment?

natural selection

which process of evolution most likely led to the large number of antibiotic resitant bacteria that we see today? (I.e., what causes antibiotic resistant bacteria to become more common than non-resistant bacteria?)

natural selection

in the video, the narrator states "hair examined under a microscope at the FBI was often sent for a DNA test." Does the DNA actually come from the hair?

no, the dna comes from cells attached to the root of the hair sample

viruses are

not alive because they are not made of cells and require a host cell for reproduction.

the ___ is the two-layered membrane that encases the nucleus of a eukaryotic cell, separating the nucleus from the cytoplasm.

nuclear envelope

a protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a _____

nuclear pore

the round body that sits inside the nucleus of a eukaryotic cell and makes ribosomal subunits from proteins and ribosomal RNA is known as the ____

nucleolus

which of the following is in the correct order from simplest to most complex?

nucleotide, amino acid, protein

which of the following is used to construct a molecule of DNA?

nucleotides

the ___ is the most prominent membrane-bound organelle in eukaryotic cells, and it houses most of a cell's DNA.

nucleus

the cellular processes that results in the production of protein begin in the ____, where the dna resides

nucleus

a technical artifact in a dna profile is referred to as a "blob" by forensic scientists. according to Dan Krane how common are blobs in DNA profiles?

occur in about every 1 in 3 dna profiles

Dan Krane states that technical artifacts can lead to bias when scientists are _______ rather than ________.

subjective; objective

individuals with variations that make them best suited to their environment will, on average, be more likely to ________.

survive and reproduce

a virus enters your system and successfully invades and infects a cell. At this point it is vulnerable to recognition or attack by _____.

t cells

this process is helped along by molecules of ____, each of which recognizes one nucleotide triplet and carries the corresponding amino acid

tRNA

which of the following contributes the LEAST to the problem of antibiotic resistance?

taking the entire course of antibiotics as prescribed by the doctor

the human immune system cannot effectively suppress the HIV virus on its own. What key feature of HIV makes it so hard to beat?

the HIV virus has an extremely high rate of mutation

although most biologists do not consider viruses to be alive, viruses do share some characteristics with living things. Which of the following is the requirement for life that viruses lack?

the ability to reproduce on their own

which part of a nucleotide molecule in DNA encodes genetic information?

the base