Principles Of Inheritance

Question 1

What is the basic unit of heredity?

Answer 1

Gene

Question 2

True or False: Alleles are alternative forms of a gene.

Answer 2

True

Question 3

Fill in the blank: The physical expression of a trait is known as its __________.

Answer 3

Phenotype

Question 4

What is the genetic makeup of an organism called?

Answer 4

Genotype

Question 5

In a monohybrid cross, what is the phenotypic ratio of the offspring?

Answer 5

3:1

Question 6

What term describes a cross between individuals that involves two traits?

Answer 6

Dihybrid cross

Question 7

True or False: Homozygous individuals have two identical alleles for a trait.

Answer 7

True

Question 8

What is the expected genotypic ratio from a dihybrid cross?

Answer 8

1:2:1:2:4:2:1:2:1

Question 9

Who is known as the father of genetics?

Answer 9

Gregor Mendel

Question 10

What is the term for a trait that is only expressed in the homozygous condition?

Answer 10

Recessive trait

Question 11

Fill in the blank: The Law of Segregation states that alleles segregate during __________.

Answer 11

Gamete formation

Question 12

What type of inheritance pattern does blood type exhibit?

Answer 12

Codominance and multiple alleles

Question 13

True or False: Sex-linked traits are associated with genes located on sex chromosomes.

Answer 13

True

Question 14

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

Answer 14

Phenotype

Question 15

In a test cross, what organism is typically used?

Answer 15

Homozygous recessive

Question 16

What is the purpose of a Punnett square?

Answer 16

To predict the genotypes and phenotypes of offspring.

Question 17

Fill in the blank: The __________ law states that alleles for different traits assort independently of one another.

Answer 17

Law of Independent Assortment

Question 18

What is the probability of obtaining a homozygous recessive offspring from a cross between two heterozygous parents?

Answer 18

25%

Question 19

True or False: Polygenic inheritance involves multiple genes affecting one trait.

Answer 19

True

Question 20

What is the term for a genetic cross that tracks the inheritance of two traits?

Answer 20

Dihybrid cross

Question 21

What is the meaning of the term ‘phenotypic ratio’?

Answer 21

The ratio of different phenotypes in the offspring.

Question 22

Fill in the blank: The term __________ refers to the genetic constitution of an organism.

Answer 22

Genotype

Question 23

What type of inheritance is characterized by blending of traits?

Answer 23

Incomplete dominance

Question 24

True or False: Environmental factors can influence phenotypes.

Answer 24

True

Question 25

What is a carrier in genetic terms?

Answer 25

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

Question 26

Fill in the blank: The __________ is a diagram that shows the occurrence of a genetic trait in several generations of a family.

Answer 26

Pedigree

Question 27

What does the term 'linkage' refer to in genetics?

Answer 27

Genes that are located close together on the same chromosome.

Question 28

True or False: Linked genes assort independently during gamete formation.

Answer 28

False

Question 29

What is the expected phenotypic ratio of a monohybrid cross?

Answer 29

3:1

Question 30

Fill in the blank: A __________ is a variant form of a gene.

Answer 30

Allele

Question 31

What is the significance of Mendel's experiments with pea plants?

Answer 31

They established the basic principles of heredity.

Question 32

What is the role of a test cross in genetics?

Answer 32

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

Question 33

What is the principle of independent assortment?

Answer 33

The principle that alleles of different genes assort independently of one another during gamete formation.

Question 34

True or False: The inheritance of two genes is always linked.

Answer 34

False

Question 35

What is a dihybrid cross?

Answer 35

A cross between two individuals that differ in two traits.

Question 36

Fill in the blank: In a dihybrid cross, the expected phenotypic ratio in the F2 generation is _____.

Answer 36

9:3:3:1

Question 37

What is the significance of Mendel's law of segregation?

Answer 37

It states that during gamete formation, the two alleles for a trait separate so that each gamete carries only one allele.

Question 38

Define the term 'gene interaction'.

Answer 38

The interaction of genes at different loci that can affect the expression of a phenotype.

Question 39

In the context of two-gene inheritance, what is epistasis?

Answer 39

A form of gene interaction where one gene masks or suppresses the expression of another gene.

Question 40

What ratio represents the phenotypic outcome of a cross between two heterozygous parents for two traits?

Answer 40

9:3:3:1

Question 41

True or False: Linked genes do not assort independently.

Answer 41

True

Question 42

What are the two types of dominance observed in gene interactions?

Answer 42

Complete dominance and incomplete dominance.

Question 43

What is meant by the term 'test cross'?

Answer 43

A cross between an individual with an unknown genotype and a homozygous recessive individual.

Question 44

What does the term 'phenotype' refer to?

Answer 44

The observable physical or biochemical characteristics of an organism.

Question 45

Name one example of a trait that demonstrates codominance.

Answer 45

ABO blood group system.

Question 46

Fill in the blank: In a dihybrid cross, the parental generation is usually represented as _____.

Answer 46

P generation

Question 47

What is the expected genotypic ratio from a dihybrid cross between two heterozygous parents?

Answer 47

1:2:1:2:4:2:1:2:1

Question 48

What is the chromosomal theory of inheritance?

Answer 48

The chromosomal theory of inheritance states that genes are located on chromosomes and that the behavior of chromosomes during meiosis and fertilization accounts for inheritance patterns.

Question 49

True or False: Chromosomes are made up of DNA and proteins.

Answer 49

True

Question 50

Fill in the blank: Each human cell contains _____ pairs of chromosomes.

Answer 50

23

Question 51

What are homologous chromosomes?

Answer 51

Homologous chromosomes are pairs of chromosomes, one inherited from each parent, that have the same genes at the same loci but may have different alleles.

Question 52

Multiple Choice: Which process separates homologous chromosomes during cell division?

Answer 52

Meiosis

Question 53

What is the role of the centromere?

Answer 53

The centromere is the region of a chromosome where the two sister chromatids are joined and where the spindle fibers attach during cell division.

Question 54

True or False: All genes are expressed in every cell of an organism.

Answer 54

False

Question 55

What is a genotype?

Answer 55

A genotype is the genetic makeup of an organism, consisting of the alleles inherited from its parents.

Question 56

Fill in the blank: The observable characteristics of an organism are referred to as its _____.

Answer 56

phenotype

Question 57

Multiple Choice: Which type of cell division results in gametes?

Answer 57

Meiosis

Question 58

What is crossing over?

Answer 58

Crossing over is the exchange of genetic material between homologous chromosomes during meiosis, leading to genetic variation.

Question 59

True or False: The chromosomal theory of inheritance was first proposed by Gregor Mendel.

Answer 59

False

Question 60

What is an allele?

Answer 60

An allele is a variant form of a gene that can produce different traits.

Question 61

Fill in the blank: The law of segregation states that during gamete formation, the two alleles for a trait separate so that each gamete carries _____ allele(s) for each gene.

Answer 61

one

Question 62

Multiple Choice: Which scientist is primarily associated with the chromosomal theory of inheritance?

Answer 62

Walter Sutton

Question 63

What is linkage in genetics?

Answer 63

Linkage refers to the tendency of genes located close to each other on a chromosome to be inherited together during meiosis.

Question 64

True or False: Linked genes always assort independently.

Answer 64

False

Question 65

What is the significance of recombination in genetics?

Answer 65

Recombination increases genetic diversity by producing new allele combinations in offspring.

Question 66

Fill in the blank: The phenomenon of _____ occurs when homologous chromosomes exchange genetic material during meiosis.

Answer 66

recombination

Question 67

What is the unit of measurement for genetic linkage?

Answer 67

Centimorgan (cM)

Question 68

Multiple Choice: Which of the following describes the term 'chiasma'?

Answer 68

A point where two homologous chromosomes exchange genetic material.

Question 69

What is the relationship between distance between genes and frequency of recombination?

Answer 69

The greater the distance between genes, the higher the frequency of recombination.

Question 70

True or False: Genes that are far apart on the same chromosome are more likely to be inherited together.

Answer 70

False

Question 71

What is the expected recombination frequency between two genes that are 10 cM apart?

Answer 71

10% recombination frequency.

Question 72

Short answer: Define crossing over.

Answer 72

Crossing over is the exchange of genetic material between homologous chromosomes during meiosis.

Question 73

What are parental types in genetics?

Answer 73

Parental types are offspring that have the same genotype as one of the parents.

Question 74

Multiple Choice: What does a recombinant type refer to?

Answer 74

Offspring with a different genotype from either parent due to recombination.

Question 75

Fill in the blank: The term _____ refers to the physical location of a gene on a chromosome.

Answer 75

locus

Question 76

Short answer: How does genetic linkage affect inheritance patterns?

Answer 76

Genetic linkage leads to non-independent assortment of alleles, affecting the ratios of offspring phenotypes.

Question 77

True or False: Linkage groups are formed by genes located on different chromosomes.

Answer 77

False