Unit 1

Question 1

How many chromosomes would be present in a mature gamete if the organism has a diploid chromosome compliment of 12?

Answer 1

6

Question 2

How many chromatids would be present in a cell at Metaphase II?

Answer 2

12

Question 3

Morgan’s experiments on the white mutation in Drosophilia indicated…

Answer 3

that the ‘exceptional progeny’ not showing crosscross inheritance arose from nondisjunction

Question 4

T/F: Mendel’s principle of ind. assortment does not apply to genes that are close together on the same chromosome (cmsm).

Answer 4

True

Question 5

T/F: In birds, the female is the heterogametic sex?

Answer 5

True

Question 6

Where is mRNA translated into protein?

Answer 6

ribosomes

Question 7

Enough enzyme activity present from a single functional allele

Answer 7

haplosufficient enzyme

Question 8

“Nothing from nothing ever yet was born…”

Answer 8

Lecretius (50 BC)

Question 9

the concept that a tiny, preformed organism was transmitted from generation to generation

Answer 9

preformationism

Question 10

Theory of Epigenesis (late 18th-19th century)

Answer 10

C.F. Wolff and K.E. von Baer: tissues and organs appear during development that are not originally present int he embryo

Question 11

When did Darwin develop his theory to address variation he saw in population?

Answer 11

1838…not published for 21 years. Voyage of the Beagle was 1831-36

Question 12

Natural Selection Arguments

Answer 12

1. Organisms Vary
2. Variation is inherited
3. All organisms produce more offspring than can possibly survive and breed

Question 13

Mendel: unit inheritance

Answer 13

factors are discrete and particulate entities; they are not mixed or diluted during inheritance

Question 14

Mendel: Principle of Segregation

Answer 14

the paired factors segregate (separate) from each other in formation of gametes

Question 15

Mendel: Principle of Inheritance:

Answer 15

Parental factors segregate at random (2 independent 3:1 ratios for each trait in a dihybrid cross)

Question 16

(~1880): Studies in early insect embryogenesis showed a population of cells that arose early in development and gave rise to the gametes. who?

Answer 16

August Wesmann

Question 17

Special type of cell division occurs in germ cells…meiosis:

Answer 17

E. Van Beneden, T. Boveri (1880s-1900)

Question 18

characteristic of autosomal dominant inheritance (in pedigree chart)

Answer 18

1) affected individuals in every generation (1/2)

Question 19

Achondroplasia and pseudoachondroplasia…what characteristics?

Answer 19

short-limbed dwarfism

Question 20

autosomal recessive inheritance traits:

Answer 20

1/4 of children affected, trait “skips” generations

Question 21

T/F: autosomal recessive traits may be associated with consanguinity (inbreeding)

Answer 21

true

Question 22

talk about CMSM theory of inheritance:

Answer 22

1902: Sutton-Boveri Hypothesis…mendelian factors-genes- are located on cmsms

Question 23

difference between meiosis between males and females:

Answer 23

Oogenesis: a single meiotic division gives rise to a single oocyte
Spermatogenesis: a single division gives rise to 4 mature sperm

Question 24

Stage of Meiosis where oocyte remains at prophase of 1st m division for 15 to 50 years:

Answer 24

Dictyotene stage

Question 25

When is 2nd meiotic division initiated for females?

Answer 25

after fertilization

Question 26

in what species are males the heterogametic sex?

Answer 26

humans, fruitflies, mealworms

Question 27

In drosophilia, XO = | and XXY =

Answer 27

male, female

Question 28

In humans, what determines maleness?

Answer 28

Y cmsm...TDF...SRY which also encodes transcription factor

Question 29

Typical X linked recessive pattern of inheritance:

Answer 29

males affected, disorder passed through female carriers

Question 30

Symptoms of Hypophophatemia:

Answer 30

short stature, bow-legs, lowered phophate levels in the blood. This is X linked dom. males transmit to none of their sons and all of their daughters

Question 31

term for males passing on trait to all males

Answer 31

holandric (TDF or SRY gene)

Question 32

trait inherited as autosomal dom, but only one sex shows the triat (example is familial male precocious puberty)

Answer 32

sex limited trait

Question 33

pattern baldness- dominant trait that is more prominent in males than in females:

Answer 33

sex influenced inheritance

Question 34

If parents are heterozygous for an autosomal recessive disorder, what is the probability of having 2 normal and 2 affected children in a 4 child family?

Answer 34

27/128 | p^4+4p^3q+6p^2q^2+4pq^3+q^4 = 1

Question 35

In 1902, who demonstrated that a human trait was transmitted according to Mendel's laws?

Answer 35

A. Garrod

Question 36

Name trait: inherited pattern of 3:1 for affected families (autosomal recessive) Garrod-"disease due to a defect in enzymatic pathway", "inborn error in metabolism" - first suggested that genes can code for enzymes

Answer 36

alcaptonuria

Question 37

phenotype of heterozygote can be distinguished from that of homozygote ie snapdragons

Answer 37

incomplete dominance

Question 38

for an organism w/ a diploid cmsm compliment of 12, how many chromatids would be present in a cell at meiotic metaphase I?

Answer 38

24

Question 39

Goal of 1st meiotic division:

Answer 39

segregate homologous copies of each cmsms

Question 40

goal of 2nd meiotic division:

Answer 40

distributes the identical copies (sister chromatids) that originated from cmsms replication

Question 41

Which of the following is true regarding sickle cell anemia screening done in the 1970s? I. The screening tests for a disease that afflicts roughly 1 in 6000 African-Americans. II. Due to insufficient educational followup, there was confusion, where some carriers mistakenly thought they had the disease. III. Screening can only be performed on potential parents; a prenatal test is not available. IV. Testing information was made available to employers and insurance companies, leading to denial of jobs and health insurance to some sickle cell carriers.

Answer 41

I. False; Frequency is 1/600 in U.S. populations; II. True; educational follow up was lacking; III. False; prenatal testing is available; IV. True; information did get out to insurers and employers.

Question 42

Huntington Disease: I. Is inherited as an autosomal recessive. II. Was a disease gene mapped to human chromosome 4 in the 1980s, using molecular techniques. III. Can be effectively treated, now that the molecular basis of the disease has been identified. IV. Is classified as a late-onset genetic disorder, since the disease neurological phenotype is manifest only later in life

Answer 42

I. False; HD is an autosomal dominant II. True; this was one of the first human genes to be mapped to a chromo- some using molecular markers; III. False; a cure is still unavailable. IV. True; symptoms of HD start to appear over time.

Question 43

protease inhibitor produced in liver; released into bloodstream. required to prevent tissue damage from released cellular proteases.

Answer 43

Alpha-1-antitryspin Gene (A-1-A)

Question 44

released from WBCs during infections; must be inactivated by A-1-A

Answer 44

neutrophil elastase

Question 45

sugar residues attached as a post translational modification, changing mobility

Answer 45

glycoprotein ie A1A

Question 46

ABO blood groups exhibit this

Answer 46

codominance

Question 47

2 copies of a particular allele will lead to death of homozygous class during embryogenesis ie yellow locus of mice...1:1 ratio of yellow/normal

Answer 47

lethal alleles. in this case, A^y allele is dominant for coat color phenotype, but recessive for the lethality phenotype

Question 48

genetic heterogeneity example

Answer 48

albinism, which can lead to complimentation (mutations carried by parents found on different genes)

Question 49

protein deficiency leads to phenocopy (mimicry due to environmental affect) of albinism

Answer 49

Kwashiorchor...symptoms go away with protein intake

Question 50

the degree or severity that a given genotype exhibits its phenotype

Answer 50

variable expressivity ie anonychia, neurofibromatosis

Question 51

some individuals of appropriate genotype go undetected in population

Answer 51

reduced or incomplete penetrance ie Marfan syndrome (extreme height, long fingers)

Question 52

pleiotropy

Answer 52

numerous phenotypic effects caused by a single gene

Question 53

if the gene has been isolated, then nucleic acid probes can be used to identify differences in gene structure

Answer 53

southern blots

Question 54

mRNa levels (direct gene product) can be detected in tissues by nucleic acid probes

Answer 54

Northern blots

Question 55

isolated gene can be expressed in vitro to produce protein antigens....antibodies raised against the recombinant proteins can be used to detect the encoded protein product

Answer 55

western blots

Question 56

southern blotting process

Answer 56

1. restriction enzymes break DNA 2. frags separated by electrophoresis, and DNA is denatured 3. Fragments transferred and then probed with a single stranded piece of a gene...detected by base paireing

Question 57

expression of lobe gene in different Drosophilia melogaster follows what pattern?

Answer 57

variable expressivity

Question 58

one gene modifying the phenotypic expression of a nonallelic gene when both genes are present in the genome

Answer 58

epistasis

Question 59

Dihybrid mods: gene action with 9:7 ratio

Answer 59

complimentary gene action ie x to y to z

Question 60

15:1 ratio...flower shape in shepherd's purse

Answer 60

duplicate gene action (dominant allele at either A or B locus will get to phenotype Z) only aabb insufficient

Question 61

epistasis where a dominant allele at the B locus will block phenotype Y , and a dom allele at A locus will lead to Z

Answer 61

dominant epistasis (12:3:1 ratio)

Question 62

9:3:4 ratio signifies what?

Answer 62

recessive epistasis

Question 63

a result of the failure of sister chromatids to segregate during meiosis II

Answer 63

nondisjunction

Question 64

refuted by Pasteur's famous "swan flask" experiment

Answer 64

spontaneous generation

Question 65

specialized chromosomal region where sister chromatids are connected

Answer 65

centromere

Question 66

formed during prophase I of meiosis, it contains a tetrad

Answer 66

synaptonemal complex

Question 67

T/F: Since the charge of the HbS protein differs from the HbA protein, HbS/HbA heterozygotes can also be detected by using the technique of protein electrophoresis.

Answer 67

true

Question 68

T/F: was the process of meiosis, discovered by the Morgan laboratory in 1900, that convinced scientists oth importance of Mendel’s observations in peas.

Answer 68

False

Question 69

Gregor Mendel: a) was educated at the University of Vienna; b) was an Augustinian monk; c) corresponded with important scientists in his field; d) all of the above; e) none of the above.

Answer 69

D all of the above

Question 70

concept that linked behavior of chromosomes in meiosis to behavior of Mendelian factors

Answer 70

Sutton-Boveri Hypothesis

Question 71

individual that brings genetic disorder to attention of clinician

Answer 71

proband

Question 72

proposed by Weismann, on basis of observations made during insect embryogenesis

Answer 72

germline reductional division