Lesson 3

Question 1

The Basic Laws of Inheritance

Answer 1

Mendelian Genetics

Question 2

Mendelian Genetics

Answer 2

• Law of Dominance
• Law of Segregation
• Law of Independent Assortment

Question 3

Any pattern of Inheritance in which traits do not segregate in accordance with Mendel’s Laws

Answer 3

Non-Mendelian Inheritance

Question 4

Non-Mendelian Inheritance

Answer 4

Co-dominance
Incomplete Dominance
Polygenic Inheritance
Multiple Alleles
Pleiotropy
Gene Linkage
Extra-nuclear Inheritance
Sex-linked Inheritance

Question 5

In crossing between homozygous organisms for contrasting characters of a pair, ONLY ONE character of the pair appears in the first generation

Answer 5

Law of Dominance

Question 6

The character that dominates

Answer 6

Dominant

Question 7

The one that remains unexpressed

Answer 7

Recessive

Question 8

Only expressed when the offspring has two copies in the same way as the dominant character

Answer 8

Recessive character

Question 9

T/F: Law of Dominance is strictly only used for genotypic characters and does not represent the phenotype of the individual

Answer 9

True

Question 10

Law of Dominance: When do homozygous chromosomes separate so that the chromosome with T or t gene is passed to the gamete

Answer 10

Gametogenesis

Question 11

Law of Dominance: When do two gamete combine and produce a new individual with both the character

Answer 11

Fertilization

Question 12

The offspring is now called _____ as it contains two different genes for a pair of contrasting characters

Answer 12

Heterozygote or hybrid

Question 13

This law is not applicable for all living organisms as it is ONLY VALID in the case of DIPLOID organisms and the organisms that undergo sexual reproduction

Answer 13

Law of Dominance

Question 14

The hybrids or heterozygotes of F1 generation have two contrasting characters of dominant and recessive nature where the alleles though remain together for a long time do not contaminate or mix with each other and separate or segregate at the time of gametogenesis so that each gamete receives only one allele of a character either dominant or recessive

Answer 14

Law of Segregation

Question 15

This law states that only a single gene copy from a parent is distributed in a gamete and the allocation of the gene copies is entirely random

Answer 15

Law of Segregation

Question 16

Allows the concept of hereditary factors that remain as separate entities even when present together with other similar entities

Answer 16

Law of Segregation

Question 17

T/F: Law of Segregation was used to disprove a blending theory by the generation of traits encoded by recessive alleles in the F1 generation

Answer 17

True

Question 18

Law that is based on the first phase of the meiotic cell division, where homologous chromosome with two copies of the same gene are segregated into individual daughter nuclei

Answer 18

Law of Segregation

Question 19

Example of Law of Segregation in human skin

Answer 19

Albinism in humans

Question 20

The lack of pigment production in humans due to the presence of an abnormal recessive trait that results in the lack of production of the tyrosinase enzyme required for the synthesis of melanin

Answer 20

Albinism

Question 21

This law is ONLY applicable to DIPLOID that are formed FROM HAPLOID gametes during sexual reproduction

Answer 21

Law of Segregation

Question 22

The law is NOT VALID for genes that are COLLABORATIVE and might vary in expression & COMPLEMENTARY

Answer 22

Law of Segregation

Question 23

What Mendelian Law works well with a monohybrid cross

Answer 23

Law of Segregation

Question 24

When the parents differ from each other in two or more pairs of contrasting characters, the inheritance of one pair of characters is independent of the other

Answer 24

Law of Independent Assortment

Question 25

The law that states all transfer of particular character from parents to the offspring remains unaffected by other characters

Answer 25

Law of Independent Assortment

Question 26

What Mendelian Law works well with a dihybrid cross

Answer 26

Law of Independent Assortment

Question 27

Based on meiosis cell division where diploid chromosomes in parents are separated to form haploid gametes that occurs independently from each other in a random manner

Answer 27

Law of Independent Assortment

Question 28

This law does NOT hold TRUE for LINKED GENES present on the SAME LOCI that are usually inherited together

Answer 28

Law of Independent Assortment

Question 29

This law is NOT APPLICABLE for genetic traits where they exhibit INCOMPLETE DOMINANCE or CO-DOMINANCE or MULTIPLE FACTORS

Answer 29

Law of Independent Assortment

Question 30

Believed to be a violation of the Law of Dominance

Answer 30

Co-dominance

Question 31

Equal expression of traits at the same time

Answer 31

Co-dominance

Question 32

When sometimes a heterozygote dominant allele does not completely mask the phenotypic expression of the recessive allele; occurs an intermediate phenotype in the heterozygote

Answer 32

Incomplete dominance

Question 33

Traits are blended together

Answer 33

Incomplete dominance

Question 34

Example: AB blood type

Answer 34

Co-dominance

Question 35

Example: Red & White = Pink

Answer 35

Incomplete dominance

Question 36

When one characteristic is controlled by two or more genes

Answer 36

Polygenic Inheritance

Question 37

Example: Skin Color

Answer 37

Polygenic Inheritance

Question 38

Multiple alleles of a given gene

Answer 38

Multiple alleles

Question 39

Example: ABO blood type & rabbit coat color

Answer 39

Multiple alleles

Question 40

Some genes that affect MANY different characteristics, not just a single characteristic

Answer 40

Pleiotropy

Question 41

Example: Marfan Syndrome

Answer 41

Pleiotropy

Question 42

Each chromosome contains more than one gene; fairly close to each other, tend to be inherited together

Answer 42

Gene Linkage

Question 43

Occurrence of certain extranuclear genes or DNA molecules in the cytoplasm of many prokaryotic and eukaryotic cells

Answer 43

Extra-nuclear Inheritance

Question 44

Example: Mitochondria and chloroplasts

Answer 44

Extra-nuclear Inheritance

Question 45

The inheritance of a trait (phenotype) that is determined by a gene located on ONE of the sex chromosomes

Answer 45

Sex-Linked Inherited

Question 46

Genes that occur exclusively on the X chromosome

Answer 46

X-Linked genes

Question 47

Genes that occur exclusively in the Y chromosome

Answer 47

holandric genes

Question 48

Inheritance in X-Linked or holandric genes

Answer 48

Sex-linked inheritance

Question 49

Genes in the differential regions are called ___ in males

Answer 49

hemizygous

Question 50

Shows criss-cross pattern of inheritance

Answer 50

X-Linked Recessive Genes

Question 51

X-linked recessive are usually found more frequently in

Answer 51

Males

Question 52

Are usually carriers

Answer 52

Females

Question 53

X-Linked: When father is affected

Answer 53

Affected: all daughters, 1/2 sons

Question 54

X-Linked: When both the mother and father bear recessive allele

Answer 54

Affected Female

Question 55

X-Linked: When only the mother carries the gene

Answer 55

Affected Male

Question 56

X-Linked: Affected Recessive male

Answer 56

None of the sons are affected

Question 57

A defect in which a person cannot distinguish between red, green or both colors from other colors

Answer 57

Color-blindness

Question 58

royal disease; lack of blood protein (clotting factor VIII and clotting factor IX) that causes the inability of blood to clot normally even after a minor injury

Answer 58

Hemophilia (Bleeder's disease)

Question 59

X-Linked are usually detected on

Answer 59

Females

Question 60

X-Linked Males pass it on ____, none on ____

Answer 60

Daughters, Sons

Question 61

X-Linked Females pass it on ______

Answer 61

1/2 to sons and daughters

Question 62

* hypophosphatemia (Vit D - resistant rickets) * hypoplastic amelogenesis (enamel hypoplasia imperfecta)

Answer 62

X-Linked examples

Question 63

Male to male direct transmission of genes in the non-homologous region of the Y chromosome

Answer 63

Y-Linked Gene Inheritance

Question 64

- ichthyosis hystrix hypertrichosis (hair on pinna of ear) - H-Y antigen, height, etc

Answer 64

Y-Linked examples

Question 65

A table checkboard grid based on the principle of independent assortment

Answer 65

Punnett Square

Question 66

Who introduced the concept of the Punnett square

Answer 66

Reginald Punnett in 1905

Question 67

Used to predict genotypes

Answer 67

Punnett squares