Bio. 112 - Animal Diversity

Question 1

What does it mean to be a carrier (for disease)?

Answer 1

Carry the recessive allele but are phenotypically normal

Question 2

Processes of Fetal Testing

Answer 2

Amniocentesis: liquid that bathes the fetus is removed and tested
Chorionic villus sampling (CVS): sample of placenta is removed and tested
Ultrasound/Fetoscopy: fetus health seen visibly

Question 3

Importance of Fetal Testing

Answer 3

Identifies carriers and help define the odds more accurately

Question 4

Why are relatives discourages from marriage?

Answer 4

Increases chances of mating between two carriers of the same rare allele, resulting in a disease

Question 5

Complete dominance

Answer 5

Phenotypes of the heterozygote and dominant homozygote are identical (PP/Pp)

Question 6

Incomplete dominance

Answer 6

Phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties (Red x White=Pink)

Question 7

Codominance

Answer 7

Two dominant alleles affect the phenotype in separate ways (both expressed; blood groups)

Question 8

Epistasis

Answer 8

Gene at one locus alters the phenotypic expression of a gene at a second locus
-One gene=pigment color; other gene=will pigment be deposited in hair

Question 9

Pleiotropy

Answer 9

Multiple phenotypic effects; responsible for multiple symptoms

Question 10

Polygenic

Answer 10

Additive effect of two or more genes on a single phenotype; indicates quantitative variation

Question 11

Phenotype

Answer 11

Physical apperance

Question 12

Genotype

Answer 12

Genetic makeup

Question 13

Homozygous (PP)

Answer 13

Two identical alleles

Question 14

Heterozygous (Pp)

Answer 14

Two different alleles

Question 15

Laws of Segregation

Answer 15

During gamete formation, copies separate so that each gamete receives only 1 copy

Question 16

Independent assortment

Answer 16

Alleles of different genes sort independently during gamete formation

Question 17

Carrier of sickle-cell disease

Answer 17

Pleiotropic alleles

Question 18

How does TRANSLOCATION relate to LEUKEMIA?

Answer 18

Leukemia is a result of translocations of chromosomes

Question 19

Cri-du-chat Syndrome

Answer 19

“Cry of the cat”; specific deletion in chromosome 5

Question 20

Turner’s syndrome

Answer 20

Monosomy X; produces X0 females, who are sterile

Question 21

Klinefelter syndrome

Answer 21

Result of an extra chromosome in a male, producing XXY individuals (sterile)

Question 22

Chromosome structure

Answer 22

Deletion - deletes
Translocation - moves from one to another
Inverse - reverses
Duplication - repeats

Question 23

Cytogenetic map

Answer 23

Indicates positions of genes with respect to chromosomal features

Question 24

Genegic map

Answer 24

Ordered list of the genetic loci along a particular chromosome; constructed by Alfred Sturtevant

Question 25

Linkage map

Answer 25

Genetic map of a chromosome based on recombination frequencies

• one map unit = 1% recombination freq.
• map units indicate relative distance and order

Question 26

Aneuploidy

Answer 26

Offspring with an abnormal number of a particular chromosome

Question 27

Monosomic

Answer 27

Only one copy of a particular chromosome (Turner‟s)

Question 28

Trisomic

Answer 28

Three copies of a particular chromosome (Downs)

Question 29

Nondisjunction

Answer 29

Pairs of homologous chromosomes do not separate normally during meiosis
- one gamete receives two of the same type of chromosome, while the other gamete receives none

Question 30

Effects w/ change of # of chromosomes

Answer 30

Miscarriages, some cancers, developmental disorders

Question 31

Polyploidy

Answer 31

An organism has more than two complete sets of chromosomes

Question 32

LINKAGE relationship w/ RECOMBINATION FREQUENCY

Answer 32

Linkage map is a genetic map of a chromosome based on recombination frequencies