Chapter 11: Inheritance

Question 1

What is the definition of monohybrid inheritance?

Answer 1

• involves the inheritance of one characteristic and contrasting traits controlled by gene

Question 2

Mendel chose the pea plant as his research materials because:

Answer 2

• can be easily grown and bears many seedlings
• has both male and female reproductive organs
• possesses contrasting traits or characteristics that are obvious
• has a short generation interval

Question 3

Purebreed plants are produced through ___-____ plant which has similar traits to that of its parent plant in terms of genetic content.

Answer 3

• self cross

Question 4

What are a gene and an allele?

Answer 4

Gene
- basic unit of inheritance
- consists of a DNA segment located at a specific locus of a chromosome
- controls a specific characteristic of an organism
Allele
- an alternative form of a gene for a specific trait that is located on the same locus of a pair of homologous chromosomes

Question 5

What are characteristics and traits?

Answer 5

Characteristics
- a heritable feature such as eye colour, height, blood group and the presence of dimples
Traits
- a variation of a specific characteristic
- EX: height is a characteristic whereas tall or dwarf is a trait

Question 6

What are dominant alleles and recessive alleles?

Answer 6

Dominant allele
- an allele that always shows its trait when it is present and suppresses the effect of a recessive allele
- represented by a capital letter
Recessive allele
- an allele that shows its trait when both alleles are recessive
- represented by a small letter

Question 7

What are homozygotes and heterozygotes?

Answer 7

Homozygotes
- Both alleles at loci of a pair of homologous chromosomes are the same
Heterozygotes
- Alleles at loci of a pair of homologous chromosomes are different

Question 8

What are dominant traits and recessive traits?

Answer 8

Dominant trait
- expressed when both alleles are dominant or one with dominant
Recessive trait
- expressed if a recessive allele is paired with another recessive allele

Question 9

What are parental generations and filial generations?

Answer 9

Parental generations
- refers to the first generation of 2 individuals which are mated to predict or analyse genotypes of their offsprings
Filial generations
- refers to a successive generation as a result of mating between individuals of purebreed parental generation

Question 10

What are purebreeds and hybrids?

Answer 10

Purebreeds
- individual which carries 2 identical alleles for a trait
Hybrids
- product of mating between 2 purebreed variations

Question 11

Mendel introduced Mendel’s First Law or Law of Segregation which states:

Answer 11

• a characteristic of an organism is controlled by a pair of alleles, and only one of the allelic pair is inherited in a gamete

Question 12

What is dihybrid inheritance?

Answer 12

• involves inheritance of 2 characteristics, each characteristic is controlled by a different gene located at a different locus

Question 13

What is Mendel’s Second Law, also known as Law of Independent Assortment?

Answer 13

• During gamete formation, each allele from a pair of alleles can combine randomly with any allele from another pair of allele

Question 14

What is a locus?

Answer 14

• a specific location of a gene in a chromosme