Chapter 11 (Test 3)

Question 1

The Blending Concept of Inheritance theory:

Answer 1

This theory stated that offspring would have traits intermediate between those of the parents.

Question 2

_______ wanted to develop a theory of evolution based on hereditary principles; blending theory was of no help.

Answer 2

Charles Darwin

Question 3

_______ was an Austrian monk.

Answer 3

Mendel

Question 4

Mendel formulated two fundamental laws of heredity in the early ____

Answer 4

1860s

Question 5

Mendel had previously studied _____ and ______ at the University of _____.

Answer 5

science and mathematics; vienna

Question 6

At the time of Mendel’s research, he was a substitute _____ teacher at a local technical high school.

Answer 6

science

Question 7

Because Mendel had a mathematical background, he used a statistical basis for his __________

Answer 7

breeding experiments

Question 8

Mendel’s particulate theory is based on the existence of minute particles—now called _____.

Answer 8

genes

Question 9

Mendel chose the garden pea, _______ , because peas were easy to cultivate, had a short generation time, and could be cross-pollinated by hand.

Answer 9

Pisum sativum

Question 10

From many varieties, Mendel chose __ true-breeding varieties for his experiments.

Answer 10

22

Question 11

_______ varieties had all offspring like the parents and like each other.

Answer 11

True Breeding

Question 12

Mendel confirmed that his tall plants always had tall offspring, i.e., were true-breeding, before crossing two different strains that differed in only one trait—this is called a ______.

Answer 12

monohybrid cross.

Question 13

A ______ is between two parent organisms true-breeding for two distinct forms of one trait.

Answer 13

monohybrid cross

Question 14

Mendel tracked each trait through ___ generations.

Answer 14

2

Question 15

__ generation is the parental generation in a breeding experiment.

Answer 15

P

Question 16

__ generation is the first-generation offspring in a breeding experiment.

Answer 16

F1

Question 17

__ generation is the second-generation offspring in a breeding experiment.

Answer 17

F2

Question 18

He performed _______ , i.e., pollen of tall plant to stigma of short plant and vice versa.

Answer 18

reciprocal crosses

Question 19

He found that the __ plants resembled only one of the parents.

Answer 19

F1

Question 20

Characteristics of other parents reappeared in about 1/4 of __ plants; 3/4 of offspring resembled the __ plants.

Answer 20

F1, F2

Question 21

The laws of Segregation? (4)

Answer 21

1. Each organism contains two factors for each trait.
2. Factors segregate during the formation of gametes.
3. Each gamete contains one factor for each trait.
4. Fertilization gives each new individual two factors for each trait.

Question 22

The gene _____ is the specific location of alleles on homologous chromosomes.

Answer 22

Locus

Question 23

Alternative versions of a gene are called ____

Answer 23

alleles

Question 24

A ______ masks or hides expression of a recessive allele; it is represented by an uppercase letter.

Answer 24

Dominant allele

Question 25

A _____ is an allele that exerts its effect only in the homozygous state; its expression is masked by a dominant allele; it is represented by a lowercase letter.

Answer 25

Recessive Allele

Question 26

The process of _____ explains Mendel’s law of segregation.

Answer 26

meiosis

Question 27

In Mendel’s cross, the parents were true-breeding; each parent had two identical alleles for a trait–they were ______, indicating they possess two identical alleles for a trait.

Answer 27

Homozygous

Question 28

_________ genotypes possess two dominant alleles for a trait.

Answer 28

Homozygous Dominant

Question 29

__________ genotypes possess two recessive alleles for a trait.

Answer 29

Homozygous recessive

Question 30

_______ genotypes possess one of each allele for a particular trait.

Answer 30

Heterozygous

Question 31

The allele not expressed in a heterozygote is a _______ allele.

Answer 31

Recessive

Question 32

_____ refers to the alleles an individual receives at fertilization (dominant, recessive).

Answer 32

Genotype

Question 33

______ refers to the physical appearance of the individual (tall, short, etc.).

Answer 33

Phenotype

Question 34

A __________ is between two parent organisms that are true-breeding for different forms of two traits; it produces offspring heterozygous for both traits.

Answer 34

Di-hybrid cross

Question 35

The ___________ only applies to alleles on different chromosomes.

Answer 35

law of independent assortment

Question 36

A ________ is used to determine the probability of genotypes and phenotypes among offspring.

Answer 36

Punnett Square

Question 37

_________ is the likely outcome a given event will occur from random chance. a. For example, with every coin flip there is a 50% chance of heads and 50% chance of tails.

Answer 37

Probability

Question 38

The _________ of probability states that the chance of two or more independent events occurring together is the product of the probability of the events occurring separately.

Answer 38

Product rule

Question 39

The ________ of probability calculates the probability of an event that occurs in two or more independent ways; it is the sum of individual probabilities of each way an event can occur; in the above example where the phenotype unattached earlobes is dominant (EE, Ee, and eE), the chance for unattached earlobes is ¼ + ¼ + ¼ = ¾.

Answer 39

Sum Rule

Question 40

A _____ is used to determine if an individual with the dominant phenotype is homozygous dominant or heterozygous for a particular trait.

Answer 40

Testcross

Question 41

By Mendel performing a ______, the law of segregation was supported.

Answer 41

testcross

Question 42

A ________ is used between an individual with the dominant phenotype and an individual with the recessive phenotype to see if the individual with the dominant phenotype is homozygous or heterozygous.

Answer 42

one trait testcross

Question 43

A ________ tests if individuals showing two dominant characteristics are homozygous for both or for one trait only, or heterozygous for both.

Answer 43

two trait testcross

Question 44

In ________ genetics problems, the individual has four alleles, two for each trait.

Answer 44

dihybrid

Question 45

Genetic disorders are medical conditions caused by a ______ of alleles on the autosomal chromosomes.

Answer 45

Single pair

Question 46

An _____ is any chromosome other than a sex (X or Y) chromosome.

Answer 46

autosome

Question 47

In a pedigree chart, males are designated by _____, females by _____

Answer 47

squares; circles

Question 48

A _____ is a heterozygous individual with no apparent abnormality but able to pass on an allele for a recessively-inherited genetic disorder.

Answer 48

Carrier

Question 49

Relatively harmless disorder resulting from an accumulation of methemoglobin in the blood. - Cause and genetic link still remain a mystery. - Symptoms include bluish-purple skin due to inability to clear abnormal blue protein from blood.

Answer 49

Methemoglobinemia

Question 50

People with methemoglobinemia lack the enzyme diaphorase, which is coded for by a gene on chromosome 22.

Answer 50

methemoglobinemia

Question 51

This is the most common lethal genetic disease in Caucasians in the U.S.

Answer 51

Cystic fibrosis

Question 52

About 1 in 20 Caucasians is a carrier, and about 1 in 3,000 newborns have this disorder.

Answer 52

Cystic fibrosis

Question 53

Autosomal Recessive Disorders:

Answer 53

Methemoglobinemia and Cystic fibrosis

Question 54

Autosomal Dominant Disorders:

Answer 54

Osteogenesis Imperfecta and hereditary Spherocytosis

Question 55

This is an autosomal dominant disorder that affects one in 5,000 newborns and is distributed equally around the world.

Answer 55

Osteogenesis Imperfecta

Question 56

Affected individuals have weakened brittle bones. Additional symptoms include unusual blue tint in the sclera of the eye, reduced skin elasticity, weakened teeth, and sometimes heart valve abnormalities.

Answer 56

Osteogenesis Imperfecta

Question 57

This genetic blood disorder results from a defective copy of a gene found on chromosome 8. -Symptoms include: spherical shape of red blood cells, and enlarged spleen.

Answer 57

Hereditary Spherocytosis

Question 58

________ is exhibited when the heterozygote has an intermediate phenotype between that of either homozygote.

Answer 58

Incomplete dominance

Question 59

True-breeding red and white-flowered four-o’clocks produce ____-flowered offspring.

Answer 59

pink

Question 60

In _________ the dominant allele does not always determine the phenotype of the individual.

Answer 60

incomplete penetrance

Question 61

________ is an example of incomplete penetrance.

Answer 61

polydactyly

Question 62

________ describes a gene that affects more than one characteristic of an individual.

Answer 62

Pleiotropy

Question 63

_________ examples include Marfan syndrome, porphyria, and sickle-cell anemia.

Answer 63

Pleiotropy

Question 64

Marfan syndrome?

Answer 64

- The mutated gene is on chromosome 15. | - Symptoms include disproportionately long arms, legs, hands, and feet; weakened aorta; poor eyesight.

Question 65

Porphyria?

Answer 65

- This disease is caused by a chemical insufficiency in the production of hemoglobin. - Symptoms include photosensitivity, strong abdominal pain, port-wine-colored urine, and paralysis in the arms and legs.

Question 66

Sickle-cell anemia?

Answer 66

- This disease is the most common inherited disorder in African Americans, affecting about 1 in 500. - The gene is on chromosome 11. - In affected individuals, the red blood cells are shaped like sickles—an abnormal hemoglobin molecule, Hbs, causes the defect.

Question 67

_________ occurs when one trait is governed by two or more sets of alleles

Answer 67

Polygenic inheritance

Question 68

_________ are controlled by many genes and may be influenced by environmental factors.

Answer 68

Polygenic traits

Question 69

An ______ gene is any gene located on the X chromosome; term is used to describe genes on the X chromosome that are missing on the Y chromosome.

Answer 69

X-linked

Question 70

_______- have an XY sex chromosome system similar to the human system; experiments can be correlated to the human situation.

Answer 70

fruit flies