Module 4—The Chromosomal Basis of Inheritance

Question 1

mendel’s 3rd law

Answer 1

law of dominance

does not reflect most traits

Question 2

Schleiden & Schwann

Answer 2

cell theory

Question 3

Walter Flemming

Answer 3

discovered chromosomes via microscopy

saw they were separated during mitosis

Question 4

Sutton & Boveri

Answer 4

connected events of meiosis with Mendel’s laws

Question 5

Thomas Hunt Morgan

Answer 5

fly lab

mapped first genes to specific chromosomes

Question 6

found by Morgan not to exhibit Mendelian inheritance

Answer 6

sex-linked traits

Question 7

hemizygous

Answer 7

describes males’ Y chromosome paired with X chromosome

Question 8

reciprocal cross

Answer 8

cross of mutant father + wild type mother, AND cross of mutant mother + wild type father

Question 9

homogametic

Answer 9

2 copies of same sex chromosome

female

Question 10

heterogametic

Answer 10

sex chromosomes differ

male

Question 11

__________ X chromosome has no effect on sons

Answer 11

paternal

Question 12

in mammals, sex is determined by….

Answer 12

presence of Y chromosome

Question 13

gene for testes development

Answer 13

SRY

Question 14

how mammals deal with double dose of X chromosomes in females

___ bodies

Answer 14

X inactivation

Barr bodies - bound up X chromosome in heterochromatin

Question 15

can become ovary or testis based on…

Answer 15

bipotential gonad

presence or absence of SRY gene

Question 16

X-O system

Answer 16

XX is female

X0 is male

Question 17

Z-W system

Answer 17

ZW is female

ZZ is male

Question 18

haplo-diploid system

Answer 18

diploids are female

haploids are male

males have no fathers; develop from unfertilized eggs

Question 19

genic sex determination

Answer 19

genes, not chromosomes, determine sex

Question 20

environmental sex determination example

Answer 20

temperature determines ratio of males in all the eggs

(reptiles)

Question 21

linked genes

Answer 21

located close together on same chromosome

Question 22

gave evidence for recombination that separated linked genes

Answer 22

production of nonparental alleles in small numbers

Question 23

recombination frequency

Answer 23

degree to which 2 linked genes assort independently due to crossing over

= 100 (total recombinants / total offspring)

Question 24

the closer two genes are, the _____ likely they will be separated

Answer 24

less

Question 25

Alfred Sturtevant

Answer 25

used recombination frequencies to map genes on particular chromosomes

Question 26

Sturtevart used __________ to calculate rates of recombination

Answer 26

3-factor crosses 3 linked genes together

Question 27

smaller recombination frequency = _______ distance between genes

Answer 27

shorter

Question 28

recombination frequency cannot exceed…

Answer 28

0.5 | (normal independent assortment)

Question 29

map of chromosomes based on recombination frequency

Answer 29

linkage map

Question 30

first whole-genome analysis

Answer 30

Alfred Sturtevant's linkage map

Question 31

chromosome scale variation

Answer 31

large scale chromosomal alterations

Question 32

tolerated better by plants

Answer 32

chromosome scale variation aneuploidy

Question 33

removal of chromosome segment example

Answer 33

deletion crit du chat syndrome

Question 34

repetiton of a segment cause?

Answer 34

duplication unequal crossing over

Question 35

reversal of a segment

Answer 35

inversion

Question 36

movement of a segment from one chromosome to a nonhomolog 2 types

Answer 36

translocation reciprocal (trading) nonreciprocal (no trading)

Question 37

duplications can lead to…

Answer 37

new functions

Question 38

subfunctionalization

Answer 38

one copy of a duplicated gene expressed in some tissue, the other in some other tissue

Question 39

neofunctionalization significance

Answer 39

duplicated gene takes on a new function potentially origin of more complex genes

Question 40

most common fate of duplications

Answer 40

degeneration / gene loss

Question 41

translocations can form… ex. chronic myeloid leukemia

Answer 41

gene fusions

Question 42

gene fusions can occur during \_\_\_\_\_

Answer 42

mitosis

Question 43

normal amount of chromosomes

Answer 43

euploidy

Question 44

aneuploidy

Answer 44

fewer or extra chromosomes

Question 45

other trisomies (besides Downs)

Answer 45

Edward Patau

Question 46

less disruptive aneuploidies located on…

Answer 46

sex chromosomes

Question 47

Klinefelter syndrome

Answer 47

male traits XXY XXYY XXXY

Question 48

Turner syndrome

Answer 48

female traits XO

Question 49

only viable monosomy

Answer 49

Turner syndrome XO

Question 50

aneuploidy results from…

Answer 50

nondisjunction events

Question 51

2 forms of nondisjunction

Answer 51

homologs fail to separate in meiosis I sisters fail to separate in meiosis II

Question 52

common carriers of whole genome duplications

Answer 52

crop plants

Question 53

autopolyploids

Answer 53

genome is duplicated; meiotic error leads to failure to separate gametes fuse to form polyploid zygote

Question 54

allopolyploids

Answer 54

chromosome sets combine from different species amphibians

Question 55

allowed for the evolution of vertebrates

Answer 55

2 genome duplication events