Exam 1: Lecture 3 & 4

Question 1

crossing over results in

Answer 1

unequal exchange of genetic material producing chromosomes with deleted or duplicated genes (common most are benign)

Question 2

crossing over is proportional to _

Answer 2

distance; greater the distance the arm from centromere ie the longer the arm, the greater amt of crossing over there is

Question 3

what happens to epigenetic modifications as a conseq of meiosis and genetic variation

Answer 3

epigenetic modifications are erased and the parent specific modifications are established (sex markers)

Question 4

comparison of mitosis, meiosis I, and meiosis II: cell division

Answer 4

in mitosis, meiosis I and II

Question 5

comparison of mitosis, meiosis I, and meiosis II: reduction in chromosome number

Answer 5

in meiosis I ONLY

Question 6

comparison of mitosis, meiosis I, and meiosis II: genetic variation produced

Answer 6

in meiosis I ONLY

Question 7

comparison of mitosis, meiosis I, and meiosis II: crossing over

Answer 7

in meiosis I ONLY

Question 8

comparison of mitosis, meiosis I, and meiosis II: random distribution of maternal and paternal chromosomes

Answer 8

in meiosis I ONLY

Question 9

comparison of mitosis, meiosis I, and meiosis II: metaphase

Answer 9

mitosis: indiv chromosomes line up
meiosis I: homologous pairs line up
meiosis II: indiv chromosomes line up

Question 10

comparison of mitosis, meiosis I, and meiosis II: anaphase

Answer 10

mitosis: chromatids separate
meiosis I: homologous chromosomes separate
meiosis II: chromatids separate

Question 11

cohesin

Answer 11

protein complex that holds the chromatids together and is key to the behavior of chromosomes in mitosis and meiosis

Question 12

spermatogenesis

Answer 12

male gamete production

Question 13

oogenesis

Answer 13

female gamete production

Question 14

how many chromosomes does a mule have?

Answer 14

63 (unbalanced and nonfunctional)

Question 15

how can these 2 species interbreed and produce live offspring? horse and donkey

Answer 15

their chromosomes carry same set of genes

Question 16

why are mules sterile?

Answer 16

different number of chromosomes and meiosis gets confused

Question 17

what are the consequences when chromosomes fail to properly segregate during meiosis?

Answer 17

when they don’t get pulled to the poles correctly, extra chromosome

Question 18

heredity

Answer 18

is the passing on of physical or mental characteristics genetically from one generation to another

Question 19

heritability

Answer 19

is the proportion of total variation between indivs in a given population that is due to genetic variation

Question 20

MC1R gene encodes

Answer 20

red hair; brown to red hair

Question 21

mendel used the _ in his studies of heredidty

Answer 21

pea plant Pisum sastivum

Question 22

homozygous

Answer 22

true breeding ie the alleles are identical

Question 23

principle of segregation what mendel law is this?

Answer 23

law 1: each indiv diploid organism possesses 2 alleles for any particular characteristic and only one is passed to offspring

Question 24

independent assortment what mendel law is this?

Answer 24

law 2: alleles segregate independently when gametes are formed; separate w/o any bias

Question 25

concept of dominance what mendel law is this?

Answer 25

law 3: genotype has 2 different alleles, the dominant allele is observed in the phenotype, other is recessive

Question 26

how can a single gene code 7 characteristics but still have independent assortment

Answer 26

genes are not close to another and therefore segregated independently

Question 27

backcrosses

Answer 27

TRUE LINES | tests theory of inheritance of dominant traits; get closer to homogeneity and valuable genes are selected

Question 28

define probability

Answer 28

likelihood of the occurrence of a particular event; predicts outcome of a genetic cross

Question 29

mathematical outcome for genetic crosses

Answer 29

btwn 0 (impossible) and 1 (certain)

Question 30

what is the rule of multiplication

Answer 30

key word: AND; 2 independent events that occur at the same time/simultaneously

Question 31

what is the rule of addition

Answer 31

key word: OR; either independent even would satisfy the condition so add probability together

Question 32

define conditional probability

Answer 32

we know 1 event and want to know the second event

Question 33

conditional probability question: | a cross is made btwn 2 heterozygous parent plants. What is the probability that a tall offspring plant is homozygous?

Answer 33

Tt x Tt TT: 0.25 Tt: 0.50 tt: 0.25 tt cannot take place because it is recessive and not counted so 3/4 left ie 3 to consider and 1 out of 3 or 1/3 will be homozygous for tall

Question 34

binomial expansion w/ 2 variables

Answer 34

(p+q)^2 is the mathematical formula to determine the probability of an outcome

Question 35

dihybrid cross and relevancy to mendel

Answer 35

involve 2 traits w/ differing alleles to reveal the principle of independent assortment

Question 36

what happens when alleles are too close

Answer 36

linkage; no separation therefore recessive traits transmit to generation in higher frequency

Question 37

chi-square goodness of fit

Answer 37

indicates the probability that the difference btwn the observed and expected values is due to chance

Question 38

assumption: random sample

Answer 38

the sample data is a random sample of a larger population

Question 39

assumption: sample size

Answer 39

is sufficiently large to prevent small sample error

Question 40

assumption: independence

Answer 40

the observations are independent of each other

Question 41

degrees of freedom

Answer 41

number of values that are free to vary minus 1

Question 42

formula for chi-square

Answer 42

(observed-expected)^2/expected

Question 43

chi-square table: left side with small numbers mean

Answer 43

high probability it happened by chance

Question 44

chi-squared table: right side with small numbers mean

Answer 44

low probability happened by chance

Question 45

multiple testing correction:

Answer 45

the more tests on a sample we analyze, higher probability that one will artifactually be associated with what I'm studying