Biology Exam 1 BIO 250 Questions And
Answers Graded A+.
Natural Selection - Answer A process in which individuals that have certain inherited traits tend to
survive and reproduce at higher rates than other individuals because of those traits.
Mutation - Answer A change in a gene or chromosome. Usually harmful
Force of selection changes with age - Answer decreases with age, selection shadow
Antagonistic pleiotropy - Answer occurs when a mutation with beneficial effects for one trait also
causes detrimental effects on other traits
Life History Trade-Offs - Answer growth, maintenance, reproduction
How does natural selection and mutation play a role in Antibiotic resistance? - Answer antibiotic
resistance is a consequence of evolution via natural selection. The antibiotic action is an environmental
pressure; those bacteria which have a mutation allowing them to survive will live on to reproduce. They
will then pass this trait to their offspring, which will be a fully resistant generation.
How can an autosomal dominant disease like Huntington's Disease still exist? Shouldn't it have been
wiped out by natural selection? - Answer By the time Huntington's develops, most have already
reproduced. Passed on genes before showing symptoms. Selection shadow.
MRSA - Answer Methicillin-Resistant Staphylococcus Aureus; an infectious disease caused by a
pathogen that is resistant to many antibiotics
TB/XDR-TB - Answer Tuburculosis/ extremely drug resistant TB
Acromegaly - Answer Tumor on pituitary. excessive growth. Andre the Giant
, Achondroplasia - Answer Inherited. Shorter stature. Long bones don't grow.
Non-disjunction - Answer Error in meiosis in which homologous chromosomes fail to separate. Leads to
abnormal number of chromosomes. Not compatible with survival.
Cri-du-Chat Syndrome - Answer A deletion of the short arm of chromosome 5 associated with an array
of congenital malformations, the most characteristic of which is an infant cry that resembles a meowing
cat.
Three requirements for natural selection - Answer variation, inheritance, differential reproductive
success
Trisomy 21 - Answer condition in which an individual has three number 21 chromosomes, resulting in
Down syndrome
Aneuploidy - Answer A chromosomal aberration in which one or more chromosomes are present in
extra copies or are deficient in number.
Turner's Syndrome - Answer Nondisjunction event. End up with one X. Severe aortic issues
Klinefelter's Syndrome - Answer XXY. typically presenting male
XYY - Answer Supermale Syndrome
Other Sex Chromosome abnormalities - Answer XX, XXXY, generally survivable if there is one X
Sickle Cell Anemia - Answer a genetic disorder that causes abnormal hemoglobin, resulting in some red
blood cells assuming an abnormal sickle shape. Get caught in small arterial systems, can't get oxygen to
certain areas. Beneficial if you have a sickle cell allele to prevent the malaria parasite
Blood Types - Answer A, B, AB and O. Type O is the universal donor and AB blood is known as the
universal recipient.
Answers Graded A+.
Natural Selection - Answer A process in which individuals that have certain inherited traits tend to
survive and reproduce at higher rates than other individuals because of those traits.
Mutation - Answer A change in a gene or chromosome. Usually harmful
Force of selection changes with age - Answer decreases with age, selection shadow
Antagonistic pleiotropy - Answer occurs when a mutation with beneficial effects for one trait also
causes detrimental effects on other traits
Life History Trade-Offs - Answer growth, maintenance, reproduction
How does natural selection and mutation play a role in Antibiotic resistance? - Answer antibiotic
resistance is a consequence of evolution via natural selection. The antibiotic action is an environmental
pressure; those bacteria which have a mutation allowing them to survive will live on to reproduce. They
will then pass this trait to their offspring, which will be a fully resistant generation.
How can an autosomal dominant disease like Huntington's Disease still exist? Shouldn't it have been
wiped out by natural selection? - Answer By the time Huntington's develops, most have already
reproduced. Passed on genes before showing symptoms. Selection shadow.
MRSA - Answer Methicillin-Resistant Staphylococcus Aureus; an infectious disease caused by a
pathogen that is resistant to many antibiotics
TB/XDR-TB - Answer Tuburculosis/ extremely drug resistant TB
Acromegaly - Answer Tumor on pituitary. excessive growth. Andre the Giant
, Achondroplasia - Answer Inherited. Shorter stature. Long bones don't grow.
Non-disjunction - Answer Error in meiosis in which homologous chromosomes fail to separate. Leads to
abnormal number of chromosomes. Not compatible with survival.
Cri-du-Chat Syndrome - Answer A deletion of the short arm of chromosome 5 associated with an array
of congenital malformations, the most characteristic of which is an infant cry that resembles a meowing
cat.
Three requirements for natural selection - Answer variation, inheritance, differential reproductive
success
Trisomy 21 - Answer condition in which an individual has three number 21 chromosomes, resulting in
Down syndrome
Aneuploidy - Answer A chromosomal aberration in which one or more chromosomes are present in
extra copies or are deficient in number.
Turner's Syndrome - Answer Nondisjunction event. End up with one X. Severe aortic issues
Klinefelter's Syndrome - Answer XXY. typically presenting male
XYY - Answer Supermale Syndrome
Other Sex Chromosome abnormalities - Answer XX, XXXY, generally survivable if there is one X
Sickle Cell Anemia - Answer a genetic disorder that causes abnormal hemoglobin, resulting in some red
blood cells assuming an abnormal sickle shape. Get caught in small arterial systems, can't get oxygen to
certain areas. Beneficial if you have a sickle cell allele to prevent the malaria parasite
Blood Types - Answer A, B, AB and O. Type O is the universal donor and AB blood is known as the
universal recipient.
