Exam 1

Question 1

Identify and describe the 6 model organisms used in Genetics

Answer 1

1. fruit fly (drosophila)
2. E coli
3. caenorhabditis (roundworm)
4. arabidopsis (thale-cress plant)
5. musculus (house mouse)
6. bakers yeast

Question 2

Understand and be able to explain the 11 fundamental concepts of Genetics

Answer 2

1. cells are two basic types (eukaryotic and prokaryotic)
2. the gene is the fundamental unit of heredity
3. genes come in multiple forms called alleles
4. genes confer phenotypes
5. genetic info is carried in DNA and RNA
6. genes are located on the chromosomes
7. chromosomes separate through the process of mitosis and meiosis
8. genetic info is transferred from DNA to RNA to protein
9. mutations are permanent changes in genetic info that can be passed from cell to cell or from parent to offspring
10. many traits are affected by multiple factors
11. evolution is genetic change

Question 3

Mendel’s law of segregation

Answer 3

each individual organism possess two alleles encoding a trait (parental and maternal)

Question 4

mendels law of independent assortment

Answer 4

alleles at different loci separate independently of one another

Question 5

multiplication rule

Answer 5

the probability of two or more independent events taking place
- ex: the probability of having two boys (.5*.5)

Question 6

addition rule

Answer 6

probability of any two or more mutually exclusive events taking place
- ex: probability of the offspring being heterozygous or homozygous dominant in two heterzygote cross

Question 7

what is binomial data

Answer 7

only two possible outcomes for a given trait
- like boy or girl, yes or no
P= (n!/s!t!)p^sp^t

Question 8

chi-square goodness of fit test is used for

Answer 8

evaluate the role of chance in producing deviations between observed and expected

Question 9

Chi-sqaure goodness of fit formula

Answer 9

x^2= [(ovs-exp)^2/ exp] + same

Question 10

is the p is low…

Answer 10

you reject the Ho
p value has to be lower than 0.05

Question 10

extrinsic or intrinsic

Answer 10

extrinsic: set of expected frequencies that are determines completely outside the data, based on prior knowledge

intrinsic: uses information directly calculated from the data itself to determine the expected frequencies, often estimation

Question 11

general sexual reproductive process

Answer 11

zygote (sex cell) undergoes meiosis creating 4 haploid gametes
gametes are fertilized (sperm and egg) which created a zygote

Question 12

monoecious

Answer 12

organism that bear both male and female reproductive structures
- like some plants

Question 13

diecious

Answer 13

individual organism has either male or female reproductive structures
- like humans

Question 14

hermaphroditism

Answer 14

both sexes are present in the same organism

Question 15

sex chromosome vs autosome

Answer 15

sex: determine the sex

autosome: any other chromosome that doesn’t determine sex

Question 16

hetero vs homo-gametic sex

Answer 16

hetero: produces two different types of gametes with respect to the sex chromosome
- male humans: XY

homo: produces gametes that are all the same
- female humans: XX

Question 17

common sex-determination systems

Answer 17

XX(F)-XO(M): some grasshoppers and other insects

XX(F)-XY(M): insects, fishes, amphibians, reptiles, mammals

ZZ(M)-ZW(F): butterflies, birds, some reptiles/amphibians

Question 18

genic sex determination

Answer 18

no distinct sex chromosomes
- plants, fungi, protozoans, and fishes

Question 19

chromosomes complements and sexual phenotypes in drosophila

Answer 19

XX is female while XO is male, they lack another X or Y chromosome

Question 19

environmental sex determination

Answer 19

environment controls the sex
- turtles, alligators, and some invertebrates

Question 20

turner syndrome

Answer 20

females who have underdeveloped secondary sex characteristics
-XO

Question 21

klinefelter syndrome

Answer 21

males who have one or more Y chromosomes and multiple X chromosomes
- XXXY, XXXXY, XXYY

Question 22

poly-x females

Answer 22

females who possess three X chromosomes
-XXX

Question 23

XYY-Males

Answer 23

no distinctive physical characteristics other thank to be really tall, learning difficulties

Question 24

Androgen insensitivity syndrome

Answer 24

females who have exterior female characteristics but lack internal structures
- instead have testes that produce testosterone
- but androgen receptor is deficient that doesn’t respond to testosterone

Question 25

what causes “male-ness” in humans

Answer 25

the sex determining Y gene (SRY)

Question 26

dosage compensation

Answer 26

mechanisms to equalize the amounts of protein produced by the single X and by two autosomes in the heterogametic sex

Question 27

barr bodies, how many are there, how do they relate to tortoiseshell cats

Answer 27

• condensed, darkly staining bodies in the nuclei of cells
• # of X left over after 1 stays active: XXXY -> 2 X’s are barr bodies
• the X inactivation shows the different color patches

Question 28

Lyon hypothesis

Answer 28

barr body was an inactive X chromosome

Question 29

additive alleles vs non-additive effects of alleles

Answer 29

additive: each allele accumulates in an regular way

non-additive: each allele accumulates in an irregular way

Question 30

Charlie Chaplin case

Answer 30

had a completely different blood type than the baby (couldn’t have given a blood type that he didn’t have)
- had to take care of the baby

Question 31

complete vs incomplete penetrance

Answer 31

complete: all cells are effected in a way

incomplete: only some cells are effected

Question 32

narrow vs broad expressivity

Answer 32

narrow: when penetrated they do not have a wide range, black or white

expressivity: when penetrated there is shades in between

Question 33

epistasis

Answer 33

when more than one locus influences a trait

Question 34

epistatic vs hypostatic gene

Answer 34

epistatic: gene that mask the other gene

hypostatic: gene that is being masked