PRASHANT KIRAD Genes: a segment of DNA that is the basic unit of heredity and
Heredity is passed from parent to child, is a molecule that contains
Heredity the process of passing down traits and characteristics genetic information for the development and functioning of an
from parents to their offspring through genes organism.
Variation The difference between individuals in a species or
Acquired Traits Inherited Traits
group of organisms
Environment variation
Genetic Variation a) Do not change germ cells Bring changes in germ cells
Importance of Variation
Variation helps organisms adapt to changing environments. b) Cannot be passed on to Can be passed on to their
It drives the evolution of new, better-adapted species. future generations progeny
Accumulation of Variation During Reproduction
c) Do not lead to evolution May lead to evolution
Asexually Variation are fewer.
Occurs due to small inaccuracies in DNA
Sexually Variation are large. Example: Losing limbs due to Example: Deformed limbs at
Occurs due to crossing over, separations of an accident birth due to a genetic defect
chromosomes.
The biological science, which deals with the mechanism Alleles: a pair of genes that occupy a specific location on a
of heredity and causes variation called genetics. particular chromosome and control the same trait
"genetics" was coined by English biologist William
Haploid cells contain a single set of chromosomes (n) and are
Bateson
Father of Genetics (Gregor Johann Mendel) formed through meiosis. They are primarily involved in sexual
reproduction, with examples including sperm and egg cells.
DNA: deoxyribonucleic acid, is a molecule that contains
Diploid cells, on the other hand, have two sets of chromosomes
genetic information for the development and functioning
(2n) and divide through mitosis. These cells make up most of
of an organism.
the body’s tissues, such as nerve and muscle cells.
Chromatin: refers to a mixture of DNA and proteins that Rules of inheritance
form the chromosomes found in the cells of humans and
other higher organisms
Chromosomes: is a DNA molecule that consists of a part
or all of the genetic material of an organism
Dominant allele Why only pea Large no. of offsprings Annual Plant
The dominant allele is the stronger of the two alleles. plant? Short Life Cycle 7 pairs of allelic
Represented by a capital letter, it determines the dominant
characteristics
traits. Monohybrid Cross Cross between two pea plants with
Dominant traits manifest in both homozygous and one pair of contrasting characters
heterozygous conditions.
Recessive allele
The recessive allele is the weaker of the two alleles.
Represented by a lowercase letter, it remains suppressed in
the presence of a dominant allele.
Recessive traits are expressed only in the homozygous
condition.
-Genotype: The unique DNA sequence or allele combination
inherited from parents.
- Phenotype: Observable traits like appearance and behavior,
influenced by genotype and environment.
Characters/traits like T are called dominant trait ( because it
Homozygous Condition: Heterozygous Condition: express itself ) and t are recessive traits.
Inherits identical alleles of a Inherits different alleles of
gene from both parents Dihybrid Cross A cross between two plants having two pairs
a gene from each parent of contrasting characters.
Phenotypic Ratio
Gregor Mendel's experiment
Round, yellow :9
Plant selected by Mendel: Pisum sativum( garden pea) .
Round, green : 3 Parents-> Round green × wrinkled yellow
used a number of contrasting characters for garden pea Wrinkled , yellow: 3
Mendel's rules for the inheritance of traits. Wrinkled, green :1
Law of Dominance: In heterozygous pairs, the dominant Self-pollination of F1 plants resulted in parental
allele masks the recessive one. phenotypes and two new mixtures.
Law of Segregation: Traits have two alleles that separate Round and yellow seeds are dominant traits.
during gamete formation; one from each parent combines New phenotype combinations indicate that genes for
during fertilization. round and yellow seeds are inherited independently.
Law of Independent Assortment: Alleles of different genes
assort independently into gametes
Heredity is passed from parent to child, is a molecule that contains
Heredity the process of passing down traits and characteristics genetic information for the development and functioning of an
from parents to their offspring through genes organism.
Variation The difference between individuals in a species or
Acquired Traits Inherited Traits
group of organisms
Environment variation
Genetic Variation a) Do not change germ cells Bring changes in germ cells
Importance of Variation
Variation helps organisms adapt to changing environments. b) Cannot be passed on to Can be passed on to their
It drives the evolution of new, better-adapted species. future generations progeny
Accumulation of Variation During Reproduction
c) Do not lead to evolution May lead to evolution
Asexually Variation are fewer.
Occurs due to small inaccuracies in DNA
Sexually Variation are large. Example: Losing limbs due to Example: Deformed limbs at
Occurs due to crossing over, separations of an accident birth due to a genetic defect
chromosomes.
The biological science, which deals with the mechanism Alleles: a pair of genes that occupy a specific location on a
of heredity and causes variation called genetics. particular chromosome and control the same trait
"genetics" was coined by English biologist William
Haploid cells contain a single set of chromosomes (n) and are
Bateson
Father of Genetics (Gregor Johann Mendel) formed through meiosis. They are primarily involved in sexual
reproduction, with examples including sperm and egg cells.
DNA: deoxyribonucleic acid, is a molecule that contains
Diploid cells, on the other hand, have two sets of chromosomes
genetic information for the development and functioning
(2n) and divide through mitosis. These cells make up most of
of an organism.
the body’s tissues, such as nerve and muscle cells.
Chromatin: refers to a mixture of DNA and proteins that Rules of inheritance
form the chromosomes found in the cells of humans and
other higher organisms
Chromosomes: is a DNA molecule that consists of a part
or all of the genetic material of an organism
Dominant allele Why only pea Large no. of offsprings Annual Plant
The dominant allele is the stronger of the two alleles. plant? Short Life Cycle 7 pairs of allelic
Represented by a capital letter, it determines the dominant
characteristics
traits. Monohybrid Cross Cross between two pea plants with
Dominant traits manifest in both homozygous and one pair of contrasting characters
heterozygous conditions.
Recessive allele
The recessive allele is the weaker of the two alleles.
Represented by a lowercase letter, it remains suppressed in
the presence of a dominant allele.
Recessive traits are expressed only in the homozygous
condition.
-Genotype: The unique DNA sequence or allele combination
inherited from parents.
- Phenotype: Observable traits like appearance and behavior,
influenced by genotype and environment.
Characters/traits like T are called dominant trait ( because it
Homozygous Condition: Heterozygous Condition: express itself ) and t are recessive traits.
Inherits identical alleles of a Inherits different alleles of
gene from both parents Dihybrid Cross A cross between two plants having two pairs
a gene from each parent of contrasting characters.
Phenotypic Ratio
Gregor Mendel's experiment
Round, yellow :9
Plant selected by Mendel: Pisum sativum( garden pea) .
Round, green : 3 Parents-> Round green × wrinkled yellow
used a number of contrasting characters for garden pea Wrinkled , yellow: 3
Mendel's rules for the inheritance of traits. Wrinkled, green :1
Law of Dominance: In heterozygous pairs, the dominant Self-pollination of F1 plants resulted in parental
allele masks the recessive one. phenotypes and two new mixtures.
Law of Segregation: Traits have two alleles that separate Round and yellow seeds are dominant traits.
during gamete formation; one from each parent combines New phenotype combinations indicate that genes for
during fertilization. round and yellow seeds are inherited independently.
Law of Independent Assortment: Alleles of different genes
assort independently into gametes
