1) Gregor Mendel discovered the basic principles of heredity through experiments with pea plants and established the concept of discrete inheritance units called genes. 2) A monohybrid cross is a breeding experiment between organisms that differ in a single trait, and Punnett squares can be used to predict the possible genotypes and phenotypes of offspring. 3) Terms like homozygous, heterozygous, dominant and recessive traits describe genetic inheritance patterns and how alleles interact to influence observable traits.

1. Science 8
4th Quarter

2. Mendelian Genetics (The Mendelian
Concept of a Gene)
Mendel instead believed that heredity is the
result of discrete units of inheritance, and every single
unit (or gene) was independent in its actions in an
individual's genome. According to this Mendelian
concept, inheritance of a trait depends on the passing-
on of these units.

3. Gregor Mendel
discovered the basic principles of
heredity and laid the mathematical
foundation of the science of genetics

4. Homozygotes
refers to how the alleles used two
different alleles to form the zygote
Other term is heterozygous

5. Dominant and Recessive Trait
An inherited trait that
results from the expression
of the dominant allele over
the recessive allele.
Dominant
An inherited trait that being or
produced by a form of a gene
whose effect can be hidden
by a dominant gene and
which can produce a
noticeable effect only when
two copies of the gene are
present
Recessive

6. Punnett Square
is a square diagram that is used to predict the
genotypes of a particular cross or breeding
experiment. It is named after Reginald C.
Punnett, who devised the approach in 1905. The
diagram is used by biologists to determine the
probability of an offspring having a particular
genotype.

7. Monohybrid Cross
A monohybrid cross is a breeding
experiment between P generation
(parental generation) organisms that
differ in a single given trait.
Multiple the letters one by one
Always write first the big letter

8. Monohybrid Cross
A monohybrid cross is a breeding
experiment between P generation
(parental generation) organisms that
differ in a single given trait.
Multiple the letters one by one
Always write first the big letter

9. Monohybrid Cross
A monohybrid cross is a breeding
experiment between P generation
(parental generation) organisms that
differ in a single given trait.
Multiple the letters one by one
Always write first the big letter

10. Monohybrid Cross
A monohybrid cross is a breeding
experiment between P generation
(parental generation) organisms that
differ in a single given trait.
Multiple the letters one by one
Always write first the big letter

11. Monohybrid Cross
A monohybrid cross is a breeding
experiment between P generation
(parental generation) organisms that
differ in a single given trait.
Multiple the letters one by one
Always write first the big letter
Genotype : 4 Gg
Phenotype: 4 Heterozygous Green Pod

12. The male and female sign emoji
♂
represents the male
sex or gender,
especially used to
indicate the male
form of an emoji
person
♀
represents the
female sex or
gender, especially
used to indicate the
female form of an
emoji person

13. Monohybrid Cross Example
A heterozygous tall pea plant (Tt) is crossed with a short
pea plant (tt). Show the cross and describe all possible
phenotypes and genotypes for the offspring.
T T
t
t
Tt Tt
Tt Tt
GENOTYPE:
4Tt
PHENOTYPE:
4 Heterozygous tall
pea plant
Since that all of the genes
starts with all capital letter
it refers to tall pea plant

14. Monohybrid Cross Example
A heterozygous tall pea plant (Tt) is crossed with a short
pea plant (tt). Show the cross and describe all possible
phenotypes and genotypes for the offspring.
T T x t t
Tt Tt
Tt
Tt
TT tt

15. Monohybrid Cross Example
A heterozygous tall pea plant (Tt) is crossed with a short
pea plant (tt). Show the cross and describe all possible
phenotypes and genotypes for the offspring.
T T x t t
Tt Tt
Tt
Tt
TTtt
TTtt