Gregor Mendel
Quiz and photos
Gregor Mendel was:
a)
b)
c)
an English scientist
who carried out
research with Charles
Darwin
a little known Central
European monk
an early 20th century
Dutch biologist who
carried out genetics
research
B is CORRECT
He worked in virtual obscurity during the mid
19th century.
Unfortunately, Charles Darwin did not know of
Mendel`s work. He was one of the few
scientists of that time who might have
understood and appreciated Mendel`s huge
contribution to science.
Which statement is true about him?
a)
b)
c)
His discoveries concerning
genetic inheritance were
generally accepted by the
scientific community when
he published them during
the mid 19th century.
He believed that genetic
traits of parents will usually
blend in their children.
His ideas about genetics
apply equally to plants and
animals.
C is CORRECT
He gave us the basis
for understanding
genetic inheritance in
all living things,
including humans. His
realization that we
inherit units or genes
was the key to it all.
Mendel believed that the characteristics of
pea plants are determined by the:
a)
b)
c)
inheritance of units or factors from both
parents
inheritance of units or factors from one
parent
relative health of the parent plants at the
time of pollination
A is CORRECT
We now call these units genes. Each
inherited trait is determined by at least one
gene from each parent.
An allele is:
a)
b)
c)
d)
another word for a gene
a homozygous genotype
a heterozygous genotype
one of several possible forms of a gene
D is CORRECT
An allele is one of two or more alternate forms
of a gene. If an individual is homozygous
(YY or GG) for a trait, it has inherited the
same allele from both parents. If it is
heterozygous (YG), it has inherited different
alleles for the trait.
Phenotype refers to the
______________________ of an individual.
a) genetic makeup
b) actual physical appearance
c) recessive alleles
B is CORRECT
Phenotype is the observable characteristics,
including physical appearance. It results from
the genotype and environmental influences.
A phenotype includes not only easily
measured traits like hair color but also less
apparent ones such as blood type.
When the genotype consists of a
dominant and a recessive allele,



the phenotype will be like the dominant
allele.
the phenotype will be like the recessive
allele.
the phenotype will be neither like the
dominant nor the recessive allele.
A is Correct
The dominant allele masks the appearance
of the recessive one. However, there are
some traits for which this simple rule of
dominance does not apply.
Assuming that both parent plants in the
diagram below are homozygous, why
would all of the f1 generation have yellow
phenotypes?
a) because the f1
genotypes are
homozygous
b) because yellow is
dominant over green
c) because both parents
passed on yellow
alleles
B is correct
When there is a genotype that consists of a
dominant and a recessive allele, the
phenotype generally looks like the dominant
one. In this case, yellow is dominant.
The idea that different pairs of alleles are
passed to offspring independently is
a) Mendel's principle of unit inheritance
b) Mendel's principle of segregation
c) Mendel's principle of independent
assortment
C is Correct
This is a definition of his principle of
independent assortment. Stated in other
words, the genes that determine a trait assort
independently of the genes for other traits.
As a result, new combinations of genes,
present in neither parent, are possible.
The idea that the pair of alleles of each
parent separate and only one allele from
each parent passes to an offspring
is Mendel's principle of independent
assortment
b) is Mendel's principle of hybridization
c) is Mendel's principle of segregation
a)
C is correct
This is the definition of the principle of
segregation. Stated in other words, genes
occur in pairs and during the process of sex
cell production, the members of each pair
separate so that each sperm and ovum cell
receives one member of each pair.
Task: Definition of terms
Pollination
Unit genes
Homozygous genotypes
Heterozygous genotypes
Allele (dominant and recessive)
Phenotype
Independent Assortment
Segregation
Hybridization
Pollination
the process that transfers pollen grains, which
contain the male gametes (sperm) to where
the female gamete(s) are contained within
the carpel
Unit Gene
A gene is a unit of Heredity
Allele
(from the Greek αλληλος allelos, meaning
each other) is one member of a pair or series
of different forms of a gene. Usually alleles
are coding sequences.
An individual's genotype for that gene is the
set of alleles it happens to possess. In a
diploid organism, one that has two copies of
each chromosome, two alleles make up the
individual's genotype.
Zygosity

It refers to the genetic condition of a zygote. In
genetics,it describes the similarity or dissimilarity of
DNA between homologous chromosomes at a
specific allelic position.

Zygosity is also used to describe the genetic
condition of the zygote(s) from which twins emerge,
where it refers to the similarity or dissimilarity of the
twins' DNA. Identical twins are monozygotic Fraternal twins are dizygotic.
Zygosity



The terms homozygous, heterozygous and hemizygous are
used to simplify the description of the genotype of a diploid
organism at a single genetic locus.
Diploid organisms generally have two alleles at each locus, one
allele for each of the two homologous chromosomes.
Homozygous describes two identical alleles or DNA sequences
at one locus, heterozygous describes two different alleles at
one locus, and hemizygous describes the presence of only a
single copy of the gene in an otherwise diploid organism.
Homozygous genotypes
Occurs when both alleles at a particular gene
locus are the same.
Heterozygous Genotype
Occurs when the two alleles at a particular
gene locus are different. A heterozygous
genotype may include one normal allele and
one mutation, or two different mutations. The
latter is called a compound heterozygote.
Phenotype
Any observable
characteristic of an
organism, such as its
morphology, development,
biochemical or physiological
properties, or behavior.
Phenotypes result from the
expression of an organism's
genes as well as the
influence of environmental
factors and possible
interactions between the
two.
Independent assortment*
Mendel's law of independent assortment,
states that allele pairs separate
independently during the formation of
gametes. This means that traits are
transmitted to offspring independently of one
another.
*Assortment : separation into classes
Segregation*
allele pairs separate or segregate during
gamete formation, and randomly unite at
fertilization
* To segregate: to separate or isolate from the main body or group
hybridization
Production of a hybrid by pairing
complementary ribonucleic acid and
deoxyribonucleic acid (DNA) strands.
Production of a hybrid by pairing
complementary DNA single strands