Monohybrid Inheritance Test Questions with Correct Answers Latest 2025-2026
Heterozygous - Answers Having two different alleles for a particular gene (Ex : Ff)
Homozygous recessibe - Answers Two recessive alleles - two of the same (Ex : ff)
Homozygous dominant - Answers Genotype is one in which both alleles are dominant (Ex : FF)
Genotype - Answers Combination of alleles an individual has
Phenotype - Answers Characteristic caused by the genotype
Incomplete/Co-dominant - Answers Both alleles contribute to the phenotype - either a blend of the two
characteristics (Both characteristics are represented)
What is an example of incomplete dominance? - Answers red flower + white flower = pink flower
Allele - Answers Alternative form of a gene found at the same locus (position on chromosome).
Variant form of a gene - different versions of the same gene/characteristic.
Gene - Answers A sequence of DNA bases that codes for a sequence of amino acids in a polypeptide.
What is the simpler definition of a gene? - Answers Sequence of nucleotide bases which code for one
characteristic.
Multiple allele - Answers A gene that has more than two alleles
Homologous chromosome - Answers Chromosomes that have the same sequence of genes and the
same structure - they both have/each have the same loci, and each carry an allele of the same gene.
Human Karyotype - Answers Number and appearance of chromosomes in humans.
What was the first thing Mendel discovered? - Answers Pea plants were inheriting a pair of genetic
instructions from each parent (alleles - different versions of the same gene passed from parent to
offspring).
What are genetic instructions now called? - Answers The genotype - decided what the outward
appearance, the phenotype was going to be.
What was the second thing Mendel discovered? - Answers Alleles were dominant and recessive
What was the third thing Mendel discovered? - Answers Even though there were dominant alleles, they
were being expressed more often than the recessive alleles.
What is Mendel's first law also referred to as? - Answers The law of segregation
What is Mendel's first law? - Answers Every individual possesses two alleles, for any particular trait - the
allele given to the offspring is completely random.
, (Dominant one is the one the offspring will express)
What is Mendel's second law also referred to as? - Answers The law of independent assortment
What is Mendel's second law? - Answers Separate genes are passed independently from each other
from parent to offspring.
Draw a diagram of Mendel's laws as evidence - Answers
What ratio did Mendel find the second generation had? - Answers 3:1
Pure breeding - Answers Both genotypes are homozygous
Gametes - Answers Sex cells, contains half the amount of chromosomes (meiosis)
Pedigree charta - Answers Used to show how genetic disorders are inherited in a family - which is then
used to work out the probability (chance) that someone in the family will inherit a condition.
What happens when the genotype is carried on the recessive genotype? - Answers There will be hidden
generations - not all the offspring have the defect.
Genetic Screening - Answers Process that involves the analysis of DNA to search for any allele that may
cause genetic problems.
Carriers of the disease/condition can be found
Family history of a particular disease can be screened in the parents
What are the four purposes of genetic screening? - Answers 1. Confirm a diagnosis - may have been
based on symptoms
2. To identify carriers
3. Important when CF is in the family history, people may want to know if there is a risk/chance of
passing the CF alleles to their offspring.
4. May be more essential when both partners have a family history of CF
How is genetic screening done? - Answers 1. Cheek cell or blood sample is taken
2. DNA from the cells is analysed in a DNA sequencer
Heterozygous - Answers Having two different alleles for a particular gene (Ex : Ff)
Homozygous recessibe - Answers Two recessive alleles - two of the same (Ex : ff)
Homozygous dominant - Answers Genotype is one in which both alleles are dominant (Ex : FF)
Genotype - Answers Combination of alleles an individual has
Phenotype - Answers Characteristic caused by the genotype
Incomplete/Co-dominant - Answers Both alleles contribute to the phenotype - either a blend of the two
characteristics (Both characteristics are represented)
What is an example of incomplete dominance? - Answers red flower + white flower = pink flower
Allele - Answers Alternative form of a gene found at the same locus (position on chromosome).
Variant form of a gene - different versions of the same gene/characteristic.
Gene - Answers A sequence of DNA bases that codes for a sequence of amino acids in a polypeptide.
What is the simpler definition of a gene? - Answers Sequence of nucleotide bases which code for one
characteristic.
Multiple allele - Answers A gene that has more than two alleles
Homologous chromosome - Answers Chromosomes that have the same sequence of genes and the
same structure - they both have/each have the same loci, and each carry an allele of the same gene.
Human Karyotype - Answers Number and appearance of chromosomes in humans.
What was the first thing Mendel discovered? - Answers Pea plants were inheriting a pair of genetic
instructions from each parent (alleles - different versions of the same gene passed from parent to
offspring).
What are genetic instructions now called? - Answers The genotype - decided what the outward
appearance, the phenotype was going to be.
What was the second thing Mendel discovered? - Answers Alleles were dominant and recessive
What was the third thing Mendel discovered? - Answers Even though there were dominant alleles, they
were being expressed more often than the recessive alleles.
What is Mendel's first law also referred to as? - Answers The law of segregation
What is Mendel's first law? - Answers Every individual possesses two alleles, for any particular trait - the
allele given to the offspring is completely random.
, (Dominant one is the one the offspring will express)
What is Mendel's second law also referred to as? - Answers The law of independent assortment
What is Mendel's second law? - Answers Separate genes are passed independently from each other
from parent to offspring.
Draw a diagram of Mendel's laws as evidence - Answers
What ratio did Mendel find the second generation had? - Answers 3:1
Pure breeding - Answers Both genotypes are homozygous
Gametes - Answers Sex cells, contains half the amount of chromosomes (meiosis)
Pedigree charta - Answers Used to show how genetic disorders are inherited in a family - which is then
used to work out the probability (chance) that someone in the family will inherit a condition.
What happens when the genotype is carried on the recessive genotype? - Answers There will be hidden
generations - not all the offspring have the defect.
Genetic Screening - Answers Process that involves the analysis of DNA to search for any allele that may
cause genetic problems.
Carriers of the disease/condition can be found
Family history of a particular disease can be screened in the parents
What are the four purposes of genetic screening? - Answers 1. Confirm a diagnosis - may have been
based on symptoms
2. To identify carriers
3. Important when CF is in the family history, people may want to know if there is a risk/chance of
passing the CF alleles to their offspring.
4. May be more essential when both partners have a family history of CF
How is genetic screening done? - Answers 1. Cheek cell or blood sample is taken
2. DNA from the cells is analysed in a DNA sequencer
