Principles Of Inheritance And Variation

Question 1

What is the basic unit of heredity?

Answer 1

Gene

Question 2

Who is known as the father of genetics?

Answer 2

Gregor Mendel

Question 3

What does a dominant allele do?

Answer 3

It masks the effect of a recessive allele.

Question 4

True or False: A homozygous organism has two different alleles for a trait.

Answer 4

False

Question 5

What is the phenotypic ratio in a monohybrid cross?

Answer 5

3:1

Question 6

Fill in the blank: The physical expression of a gene is called its ______.

Answer 6

phenotype

Question 7

What is the genotypic ratio in a dihybrid cross?

Answer 7

9:3:3:1

Question 8

True or False: Recessive traits can be expressed in the phenotype of a heterozygous individual.

Answer 8

False

Question 9

What is an allele?

Answer 9

An alternative form of a gene.

Question 10

What type of inheritance pattern is observed in blood types?

Answer 10

Codominance

Question 11

Fill in the blank: A cross between a homozygous dominant and a homozygous recessive organism is called a ______ cross.

Answer 11

test

Question 12

What is the purpose of a Punnett square?

Answer 12

To predict the genetic outcomes of a cross.

Question 13

What does the term ‘pleiotropy’ refer to?

Answer 13

A single gene influencing multiple traits.

Question 14

True or False: Sex-linked traits are inherited independently of other traits.

Answer 14

False

Question 15

What is the expected phenotypic ratio in a typical dihybrid cross?

Answer 15

9:3:3:1

Question 16

What is meant by ‘incomplete dominance’?

Answer 16

The phenotype is a blend of the two alleles.

Question 17

Fill in the blank: The genetic makeup of an organism is called its ______.

Answer 17

genotype

Question 18

What is a carrier in genetic terms?

Answer 18

An individual who has one recessive allele for a trait but does not express it.

Question 19

True or False: Mendel’s laws apply only to traits controlled by a single gene.

Answer 19

False

Question 20

What is the principle of segregation?

Answer 20

The two alleles for a trait separate during gamete formation.

Question 21

What is a test cross used for?

Answer 21

To determine the genotype of an organism with a dominant phenotype.

Question 22

Fill in the blank: The law of independent assortment states that ______.

Answer 22

alleles for different traits segregate independently.

Question 23

What is a dihybrid cross?

Answer 23

A cross involving two traits.

Question 24

What is the role of a pedigree chart?

Answer 24

To trace the inheritance of traits through generations.

Question 25

What does 'hemizygous' refer to?

Answer 25

Having only one allele for a gene, as seen in males for X-linked traits.

Question 26

True or False: All mutations are harmful.

Answer 26

False

Question 27

What is the difference between genotype and phenotype?

Answer 27

Genotype is the genetic makeup; phenotype is the physical expression.

Question 28

Fill in the blank: Traits controlled by genes on the sex chromosomes are called ______ traits.

Answer 28

sex-linked

Question 29

What is epistasis?

Answer 29

The interaction between genes such that one gene masks the effect of another.

Question 30

What is the function of a gene?

Answer 30

To code for proteins that determine traits.

Question 31

What does 'autosomal' mean?

Answer 31

Referring to chromosomes that are not sex chromosomes.

Question 32

True or False: A single gene can have multiple alleles.

Answer 32

True

Question 33

What is the expected ratio for a monohybrid cross of heterozygous parents?

Answer 33

3:1

Question 34

What is the term for a genetic cross that involves two traits?

Answer 34

Dihybrid cross

Question 35

Fill in the blank: Genetic variation can arise from ______ and environmental influences.

Answer 35

mutations

Question 36

What does the term 'homozygous' mean?

Answer 36

Having two identical alleles for a gene.

Question 37

What is a recessive allele?

Answer 37

An allele that is masked by a dominant allele.

Question 38

True or False: All traits are controlled by multiple genes.

Answer 38

False

Question 39

What is a monohybrid cross?

Answer 39

A genetic cross involving a single trait.

Question 40

What does the term 'codominance' mean?

Answer 40

Both alleles in a heterozygote are fully expressed.

Question 41

Fill in the blank: The observable characteristics of an organism are its ______.

Answer 41

phenotype

Question 42

What is the principle of dominance?

Answer 42

In a heterozygote, one allele may mask the effect of another.

Question 43

What are linked genes?

Answer 43

Genes located close together on the same chromosome.

Question 44

True or False: Genetic drift can affect allele frequencies in a small population.

Answer 44

True

Question 45

What does 'transgenic' mean?

Answer 45

An organism that contains a gene or genes which have been artificially inserted.

Question 46

What is a mutation?

Answer 46

A change in the DNA sequence of a gene.

Question 47

Fill in the blank: The ______ generation is the offspring of the parental generation in genetics.

Answer 47

F1

Question 48

What is the role of the environment in gene expression?

Answer 48

It can influence the phenotype of an organism.

Question 49

What does it mean for an allele to be 'dominant'?

Answer 49

It expresses its effect even in the presence of a recessive allele.

Question 50

True or False: The phenotype can be influenced by multiple genes.

Answer 50

True

Question 51

What is a pedigree analysis used for?

Answer 51

To study inheritance patterns in families.

Question 52

What is the significance of Mendel's experiments?

Answer 52

They established the basic laws of inheritance.

Question 53

Fill in the blank: The ______ is the genetic makeup of an organism.

Answer 53

genotype

Question 54

What is a hybrid organism?

Answer 54

An organism that has two different alleles for a trait.

Question 55

What is the expected phenotypic ratio for a test cross?

Answer 55

1:1

Question 56

True or False: All alleles are expressed equally in the phenotype.

Answer 56

False

Question 57

What is the term for organisms with the same phenotype but different genotypes?

Answer 57

Phenotypic variance

Question 58

What is incomplete dominance?

Answer 58

A form of inheritance where neither allele is completely dominant.

Question 59

Fill in the blank: The ______ law states that alleles segregate during gamete formation.

Answer 59

segregation

Question 60

What is the impact of mutations on evolution?

Answer 60

They provide the raw material for natural selection.

Question 61

What is the role of a genetic counselor?

Answer 61

To provide information and support regarding genetic conditions.

Question 62

What is the term for the observable characteristics of an organism?

Answer 62

Phenotype

Question 63

True or False: The environment has no effect on the expression of traits.

Answer 63

False

Question 64

What does 'X-linked inheritance' refer to?

Answer 64

Traits that are associated with genes on the X chromosome.

Question 65

What is the significance of polygenic inheritance?

Answer 65

It leads to a wide range of phenotypes.

Question 66

Fill in the blank: The ______ generation is the first generation in a genetic cross.

Answer 66

P

Question 67

What is a genetic disorder?

Answer 67

A disease caused by abnormalities in an individual's genetic material.

Question 68

What is the expected ratio for a dihybrid cross?

Answer 68

9:3:3:1

Question 69

True or False: A test cross can help identify whether an individual is homozygous or heterozygous.

Answer 69

True

Question 70

What is the primary focus of population genetics?

Answer 70

The study of genetic variation within populations.

Question 71

What are autosomes?

Answer 71

Chromosomes that are not involved in sex determination.

Question 72

Fill in the blank: The presence of a dominant allele will always ______ the recessive allele.

Answer 72

mask

Question 73

What is the significance of studying genetic variation?

Answer 73

It helps understand evolution and adaptation.