genetics test


factors present in each organism that are the different forms of a gene

broken genes are...

(mutations) recessive

recessive alleles

2 must be present to be seen

dominant alleles

only 1 has to be present to be seen

principle of segregation

when 2 alleles separate when gametes are formed

principle of independent assortment

alleles separate independently from 1 another during gamete formation (not true when genes are linked)

human blood types

nonmendelian: inherited by multiple alleles; type A and B are codominant and both are dominant over O

type O blood is the...

universal donor

type AB blood is the...

universal reciever


any foreign substance or cell in the body that reacts with antibodies

rH factor

simple dominant or recessive; inherited independently on A, B, and O blood types

multiple alleles

three or more alleles of the same gene


when you can see both traits in an organism (red and white flowers)

incomplete dominance

neither gene is dominant (pink flowers)


1/more gene masks another (hair, labs (dogs))

polygenic inheritance

multiple genes control/blend for 1 trait (skin pigment, height, weight), also affected by environmental factors; causes a bell curve


1 gene affects multiple characteristics (sickle cell anemia)

sex-linked traits

carried on X chromosome (XX-female, XY-male); ex: calico cats (females have XBXR)

autosomal-recessive diseases

albinism, cystic fibrosis, huntington's disease, sickle cell disease

sex-linked diseases


mosaic organism

calico cats; where different body parts have cells originating from 2 separate lines (zebra x horse)

dosage compensation

genetic mechanisms that equalize the expression of X-linked genes in males and females

Barr Body

inactivated X chromosome (marsupials inactivate their paternal X chromosome- kangaroos, koalas)


heritable change in genetics of a population

gene pool

all genes in a population

phenotypic/genotypic frequencies

% of organisms that have that phenotype/genotype

hardy-weinburg principle

p^2 + 2pq + q^2 (p^2=homozygous dominant, q^2= homozygous recessive, 2pq=heterzygous)

gene flow

change in allele frequency as individuals move in and out (not major)

genetic drift

random changes in a population due to chance events (more effective in smaller populations)

nonrandom mating

choosing based on genotypic/phenotypic traits; there will be a shift in the gene pool

bottleneck effect

population reduced to a small size and surviving grow to create new population that's basically identical (rhinos, buffaloes)

founder effect

few individuals from a population start a new population w/different allele frequencies that the original population

directional selection

organisms near 1 end of the phenotypic spectrum have the highest relative fitness (leave the most surviving offspring) (peppered moths in england)

stabilizing selection

individuals expressing intermediate phenotypes have the highest relative fitness; extremes are eliminated and phenotypes become similar (number of spines on a cactus, bird eggs)

disruptive selection

extreme phenotypes have higher relative fitness than intermediate phenotypes (results in polymorphism-2 species-and leads to speciation) (butterflies)

sexual selection

development of certain characteristics in males/females give them a better chance to mate (not necessarily survive)

sexual dimorphism

major difference between males/females; results from sexual selection (peacocks)

when phenotypes are favored at one extreme of a normal distribution, this is an example of ________________ selection


coat color in mice is determined by genes at two loci. when black mice from a particular population mate, they produce offspring in the ratio of 9 black: 3 brown: 4 white. these results suggest that the white coat color expressed is the result of...


what can be diagnosed by examining a karyotype of an individual's white blood cells?

down syndrome

a population of butterflies on an island can be green, brown, or red. the island contains much green vegetation and much brown vegetation in which the green and brown are camouflaged. the red butterflies are easy prey for birds. one would expect the follo

directional selection

a paternal chromosome in an organism has the alleles LMn, the maternal chromosome has the alleles lmN; what can be produced w/o crossing over occuring?


a diploid individual has a maximum of ___________ different alleles for a particular locus


mendel's principle of segregation...

explains the behavior of a pair of alleles during meiosis

mendel's dihybrid, not his monohybrid crosses showed that...

alleles for different traits were inherited independently

a boy has parent who both have dark skin, but he can't tell what his genes should because he is albino (2 non-functioning copies of the gene); this is an example of...


which is an example of sexual selection: mane of a lion, pesticide resistance in insects, finches in the galapagos, or dark peppered moths?

mane of a lion

human height varies over a standard distribution (bell curve) the inheritance of height is an example of...

polygenic inheritance

because of human predation in the 20th century, the average size of most whale species decreased; this is an example of...

directional selection

the fact newborn humans tend to weigh between 6 and 8 pounds is an example of...

stabilizing selection

in upstate SC, there are timber rattlesnakes (with darker stripes) in the lower state, they have the same species known as a canebrake rattlesnake (greyer color). this difference is an example of...

disruptive selection

the unusually high rate of polyploidy among the Amish is an example of...

the founder effect

a person is having their blood type determined. two drops of their blood are taken and put on a slide. antibody A is applied to one drop and antibody B is applied to the other. both drops coagulate; this person has blood type...

type AB

in one type of mice, the color ranges from white to darkest brown with every shade of brown in between. this pattern of inheritance is most likely the result of...

multiple genes (polygenic)

in a certain species of rose, the gene for red (R) flowers is dominant over that for white (r). the most likely physical explanation for this is...

both genes code for the same protein, but the gene for white is defective; w/no red, the flower is white

a man has huntington's disease, but his father lived to 98 years old, this man has a daughter; what is the chance that she will develop the disease?


which of the following organisms has traits that can be explained only by the phenomenon of Barr bodies: albino human, short pea plant, calico cat, female w/hemophilia, spotted snapdragon?

calico cat

it is reasonably accurate to say that Dodo birds went extinct due to the fact that they...

had evolved to their specific environment so much that they couldn't survive change

what is not a part of darwin's theory of evolution by natural selection?

mutations are the ultimate source of genetic variation

peacocks, cardinals, frigate birds and lions all strongly exhibit...

sexual dimorphism

if you have a tall plant, but don't have its genotype, which of the following would be a method of determining this information?

cross the plant with a short plant and observe the results in the offspring

a genetic researcher finds that in a species of rodent in brazil, a certain recessive allele tends to kill all individuals who are homozygous for the trait. they usually die shortly after birth. over time, however, the frequency of this gene appears to be

heterozygous individuals have some advantage

in certain birds, the males are much more brightly colored that are the females. this is a result of...

sexual dimorphism