Chapter 14: Mendel and the Gene Idea

Question 1

Gregor Mendel

Answer 1

Discovered basic principles of heredity and identified two laws of inheritance

Question 2

Character

Answer 2

Inheritable feature that varies among individuals (eye color, height, flower color)

Question 3

Trait

Answer 3

A variant of an inheritable character (purple flowers, white flowers)

Question 4

True-breeding

Answer 4

Always producing offspring with the same traits as the parents when the parents are self-fertilized

Question 5

Hybridization

Answer 5

Mating two contrasting, true-breeding varieties

Question 6

P generation

Answer 6

True-breeding parents

Question 7

F1 generation

Answer 7

Hybrid offspring of the P generation

Question 8

F2 generation

Answer 8

F1 self pollinate or cross pollinate with other F1 hybrids

Question 9

Allele

Answer 9

Alternate version of a gene

Question 10

Law of segregation

Answer 10

Two alleles of a heritable character separate during gamete formation and end up in different gametes

Question 11

Homozygote/homozygous

Answer 11

Organism with two identical alleles for a gene

Question 12

Heterozygote/heterozygous

Answer 12

Organism with two different alleles for a gene

Question 13

Phenotype

Answer 13

Physical appearance

Question 14

Genotype

Answer 14

Genetic makeup

Question 15

Testcross

Answer 15

Breeding a mystery individual with a homozygous recessive individual

Question 16

Monohybrid

Answer 16

F1 offspring in a cross that are heterozygous for one character

Question 17

Dihybrid

Answer 17

F1 offspring that are heterozygous for two characters

Question 18

Complete dominance

Answer 18

Phenotypes of the heterozygote and dominant homozygote are identical

Question 19

Incomplete dominance

Answer 19

Phenotype of F1 hybrids is somewhere between the phenotypes of two parental varieties (red + white = pink)

Question 20

Codominance

Answer 20

Two dominant alleles affect the phenotype in separate, distinguishable ways

Question 21

Pieotropy

Answer 21

Genes that have multiple phenotypic effects

Question 22

Epistasis

Answer 22

A gene at one locus alters the phenotypic expression of a gene at a second locus

Question 23

Quantitative characters

Answer 23

Characters that vary in the population along the continuum

Question 24

Polygenic inheritance

Answer 24

Additive effect of two or more genes on a single phenotype

Question 25

Pedigree

Answer 25

Family tree that describes the inheritance of a trait across generations

Question 26

Carriers

Answer 26

Heterozygous individuals who carry the recessive allele but are phenotypically normal

Question 27

Cystic fibrosis

Answer 27

Most common lethal genetic disease in the US, buildup of chloride ions outside the cell

Question 28

Sickle-cell disease

Answer 28

Includes physical weakness, pain, organ damage and paralysis

Question 29

Huntingtons disease

Answer 29

Degenerative disease of the nervous system

Question 30

Amniocentesis

Answer 30

Liquid that bathes the fetus is removed and tested

Question 31

Chorionic villus sampling (CVS)

Answer 31

Sample of placenta is removed and tested