Heredity

Question 1

Character

Answer 1

A heritable feature in an organism

Question 2

Trait

Answer 2

Variants of a character

Question 3

True-breeding

Answer 3

A scenario where self-pollination always produces the same organism

Question 4

P generation

Answer 4

True-breeding parental generation

Question 5

F1 generation

Answer 5

Direct hybrids of true-breeding generation

Question 6

F2 generation

Answer 6

Self-pollination of F1 generation

Question 7

Dominant trait

Answer 7

A trait that is expressed over the recessive trait

Question 8

Alleles

Answer 8

Alternative version of genes

Question 9

Somatic cell

Answer 9

Body cell (non-sex cell)

Question 10

Law of segregation

Answer 10

Two alleles for a character segregate during meiosis and arrive at different gametes

Question 11

Homozygous

Answer 11

Pair of identical alleles

Question 12

Heterozygous

Answer 12

Pair of different alleles (dominant one is expressed)

Question 13

Phenotype

Answer 13

Physical appearance of a gene

Question 14

Genotype

Answer 14

The genetic makeup

Question 15

Testcross

Answer 15

A cross between recessive and an unknown organism to determine if the genotype is homozygous dominant or heterozygous

Question 16

Monohybrid cross

Answer 16

Cross of two organisms that are hybridized for one trait (3:1 phenotypic ratio)

Question 17

Dihybrid cross

Answer 17

Cross of two organisms that are hybridized for two traits (9:3:3:1 phenotypic ratio)

Question 18

Law of independent assortment

Answer 18

Pairs of allele segregates independently of other pairs during gamete formation

Question 19

Complete dominance

Answer 19

Heterozygotes exhibit no phenotypic trace of the recessive allele

Question 20

Incomplete dominance

Answer 20

Heterozygotes have a mixture, or blending, of both alleles

Question 21

Codominance

Answer 21

Heterozygotes exhibit both alleles at once

Question 22

Tay Sachs disease

Answer 22

Disease with improperly functioning enzymes that lead to lipid accumulation in the brain; requires two alleles to manifest, but just one allele produces mediocre enzymes

Question 23

Blood types

Answer 23

A, B, AB, O (describing surface carbs of a blood cell)

Question 24

Pleiotropy

Answer 24

A condition where a gene is affected by multiple phenotypes

Question 25

Epistasis

Answer 25

Phenotypic expression of one gene alters expression of a second gene

Question 26

Polygenic inheritance

Answer 26

Phenotype is influenced by multiple genes

Question 27

Multifactorial genes

Answer 27

Character influenced by genetic and environmental factors

Question 28

Pedigree

Answer 28

Family tree describing traits of parents and descendants

Question 29

Carriers

Answer 29

Heterozygotes who carry recessive alleles for a condition without expressing them

Question 30

Cystic fibrosis

Answer 30

A disease preventing proper chloride ion transport in certain cells, causing thick mucus buildup

Question 31

Sickle cell disease

Answer 31

A condition resulting in warped blood cells which cannot hold oxygen well

Question 32

Sickle cell trait

Answer 32

The heterozygotic condition of sickle cell disease; results in some sickled and some regular blood cells

Question 33

Huntington's disease

Answer 33

A late-onset disease that is passed onto offspring well before it manifests

Question 34

Amniocentesis

Answer 34

Fetal testing using cultured amniotic cluid

Question 35

Chorionic villus sampling

Answer 35

Fetal testing using cultured placenta tissue

Question 36

PKU

Answer 36

A disorder that prevents breakdown of phenylalanine

Question 37

Benefits of Drosophila in experiments

Answer 37

Short generation time, plenty of offspring, four pairs of chromosomes

Question 38

Sex-linked gene

Answer 38

A gene present on a sex chromosome

Question 39

Systems of sex chromosomes

Answer 39

X-Y: gamete in sperm dictates sex Z-W: gamete in egg dictates sex X-0: males have one sex chromosome Haploid-diploid: females are diploid, males are haploid

Question 40

SRY

Answer 40

A gene on the Y chromosome that causes testes to form

Question 41

Hemizygous

Answer 41

Describes a male with one allele present on the Y chromosome

Question 42

Barr body

Answer 42

Condensed remnant of inactivated X chromosome

Question 43

Linked genes

Answer 43

Occur near each other on the same chromosome

Question 44

Recombinants

Answer 44

Offspring with different traits from the parents

Question 45

Recombination frequency

Answer 45

Percent of offspring with recombinant type

Question 46

Crossing over

Answer 46

Produces recombination

Question 47

Linkage map

Answer 47

A representation of recombination frequencies

Question 48

Nondisjunction

Answer 48

Failure of homologous chromosomes to separate

Question 49

Aneuploidy

Answer 49

Abnormal number of a single chromosome

Question 50

Monosomy

Answer 50

A chromosome is missing from a pair

Question 51

Trisomy

Answer 51

A chromosome is added to a pair

Question 52

Polyploidy

Answer 52

An entire set of chromosomes is replicated

Question 53

Deletion

Answer 53

Chromosome fragment is lost

Question 54

Duplication

Answer 54

Chromosome fragment is duplicated

Question 55

Inversion

Answer 55

Chromosome segment is reversed

Question 56

Translocation

Answer 56

Chromosome segment moves to another, non-homologous chromosome

Question 57

Trisomy 21

Answer 57

Down's syndrome, results in developmental delays and physical aberrations

Question 58

Klinefelter syndrome

Answer 58

XXY, sterile male sex organs

Question 59

Turner syndrome

Answer 59

Monosomy X, sterile female sex organs