exam 5 Flashcards

Question

multiplication rule

Answer 1

multiply the probability of one event by the probability of another

Answer 2

the probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities

Answer 3

mendelian genetics | dominant allele has complete dominance and is the only one shown over the recessive allele

Answer 4

blended intermidiate not completely dominant white+red=pink

Answer 5

two alleles each affect the phenotype in separate distinguishable ways black spots on a white chicken

Answer 6

an inherited disorder in humans the brain cells of a child with this cannot metabolize certain lipids because a crucial enzyme does not work properly as these lipids accumulate in brain cells, the child begins to suffer seizures, blindness and degeneration of motor and mental performance and dies within a few years

Answer 7

genes that have multiple phenotypic effects | one gene codes for more than one thing

Answer 8

a gene at one locus alters that of a gene at a second locus | labradors (217)

Answer 9

characters vary in the population in gradations along a continuum skin color

Answer 10

quantitative variation usually indicates polygenic inheritance, the additive effect of two or more genes on a single phenotypic character reverse pleiotropy: many genes code for one phenotype

Answer 11

many factors, both genetic and environmental, collectively influence phenotype

Answer 12

geneticists assemble information about members of a family into a tree diagram that describes the traits of parents and children across the generations

Answer 13

square is male | circle is female

Answer 14

heterozygotes may transmit the recessive allele to their offspring and thus are called carriers

Answer 15

common lethal genetic disease in the united states most common in european descent (4% carriers) the normal allele for this gene codes for a membrane protein that functions in the transport of chloride ions between certain cells and the extracellular fluid. these chloride channels are defective or absent in the plasma membrane of children who inherit two recessive alleles for cystic fibrosis

Answer 16

most common inherited disorder among people of african descent 1/400 african americans caused by the substitution of a single amino acid in the hemoglobi protein of red blood cells; in homozygous individuals, all hemoglobin is of the sickle cell variety

Answer 17

form of dwarfism that occurs in one of every 25,000 people | dominant allele

Answer 18

degenerative disease of the nervous system, caused by a lethal dominant allele that has no obvious phenotypic effect until the individual is about 35-45 years old. once the deterioration of the nervous system begins, it is irreversible and inevitably fatal

Answer 19

mendelian genes have specific loci along chromosomes, and it is the chromosomes that undergo segregation and independent assortment

Answer 20

experimental embryologist | used Drosophila Melanogaster to do experiments on sex linked genes

Answer 21

prolific breeders: single mating will produce hundreds of offspring and a new generation can be bred every 2 weeks only 4 pairs of chromosomes which are easily distinguishable under a light microscope

Answer 22

the phenotype for a character most commonly observed in natural populations (w+)

Answer 23

traits that are alternatives to the wild type they are due to alleles assumed to have originated as changes, or mutations in the wild type allele (w)

Answer 24

a gene located on either sex chromosome those on Y: Y-linked genes those on X: X-linked genes

Answer 25

used for describing traits in males since they only have one possibility for an allele

Answer 26

affects about 1 in every 3500 males born in the US disease is characterized by a progressive weakening of the muscles and loss of coordination rarely live past their 20s

Answer 27

x-linked recessive disorder absences of one or more of the proteins required for blood clotting when a person with hemophilia is injured bleeding is prolonged because a firm cut is slow to form

Answer 28

inactive condensed X chromosome most barr body genes are not expressed barr body chromosomes are activated in the ovaries

Answer 29

genes located near each other on the same chromosome tend to be inherited together in genetic crosses

Answer 30

result from crossing over | the production of offspring with combinations of traits that differ from those found in either P generation parent

Answer 31

offspring that inherit the phenotype that matches eithe of the parental (P) generation phenotypes

Answer 32

nonparental phenotypes that do not reseble either parent

Answer 33

accounts for the recombination of linked genes in crossing over, which occurs while replicated homologous chromsomes are paired during prophase of meiosis I, a set of proteins orchestrates an exchange of corresponding segments of one maternal and one parental chromatid

Answer 34

Alfred H. Sturtevant | an ordered list of the genetic loci along a particular chromosome

Answer 35

percentage of recombinant offspring

Answer 36

genetic map based on recombination frequencies

Answer 37

one map unit is equivalent to 1% recombination frequency | centimorgan

Answer 38

members of a pair of homologous chromosomes don't move apart properly during meiosis ! or sister chromatids fail to separate during meiosis ii

Answer 39

if either of the aberrant gametes unites with a normal one at fertilization, the zygote will also have an abnormal number of a particular chromosome

Answer 40

fertilization involving a gamete that has no copy of a particular chromosome will lead to a missing chromosome in the zygote 2n-1

Answer 41

if a chromosome present in triplicate in the zygote | 2n+1

Answer 42

plants 3n 4n

Answer 43

chromosomal fragment is lost

Answer 44

repeats a chromosomal segment

Answer 45

a chromosomal fragment reattaches to the origninal chromosome but in the reverse orientation

Answer 46

fragment joins a nonhomologous chromsome switch occurs reciprocal mostly

Answer 47

trisomy 21 one additional chromosome 21 disorder

Answer 48

XXY | 1/500-1000 live male births

Answer 49

cry of the cat deletion of chromosome 5 baby cries like cat dies