01.
Heridity & evolution
Deoxyribonucleic acid (DNA):
i) Two parallel threads of nucleotides ( many small molecules) are coiled
around each other. This arrangement is called a ‘double helix’.
ii) This sturcture can be compared with a coiled and flexible ladder.
Cell
Gene
Nucleus
of cell
cromosome
iii) In the structure of the nucleotide, a molecule of a nitrogenous base and
phosphoric acid are each joined to a molecule of sugar.
iv) There are four types of nitrogenous bases:
adenine, guanine, cytosine and thymine.
v) Adenine and guanine are called as ‘purines’
vi) while cytosine and thymine are called ‘pyrimidines’.
Ribonucleic acid (RNA) :
i) RNA is the second important nucleic acid of the cell.
ii) This nucleic acid is made up of ribose sugar, phosphate molecules and
nitrogenous bases.
iii) four types of adenine nitrogenous bases:
adenine, guanine, cytosine and uracil.
there are three types of RNA:
1. Ribosomal RNA (rRNA) :
i) The molecule of RNA which is a
component of the ribosome organelle
is called a ribosomal RNA.
ii) Ribosomes perform the function of
protein synthesis.
, 02.
2. Messenger RNA (mRNA) :
i) The RNA molecule that carries the
information of protein synthesis from
genes i.e. DNA chain in the cell nucleus
to ribosomes in the cytoplasm which
produce the proteins, is called
messenger RNA.
3. Transfer RNA (tRNA) :
The RNA molecule which, according to the
message of the mRNA carries the amino
acid up to the ribosomes is called transfer
RNA.
Science of heredity:
The science of heredity is useful for diagnosis, treatment and prevention of
hereditary disorders, production of hybrid varieties of animals and plants and
in industrial processes in which microbes are used.
Central Dogma: (protein synthesis process)
1) Information about protein synthesis is stored in the DNA and synthesis of
appropriate proteins as per requirement is necessary for body to grow &
development of orgen.
2) These proteins are synthesized by DNA through the RNA. This is calledm
as ‘Central Dogma’.
Transcription: (mRNA synthesis process)
1) Def: Process of mRNA synthesis from DNA by the help of DNA dependent
RNA polymerase II enzyme. This process is called as Transcription.
2) DNA dependent
DNA -------------------------------------> mRNA
RNA polymerase II enzyme
3) It present in nucleus.
Heridity & evolution
Deoxyribonucleic acid (DNA):
i) Two parallel threads of nucleotides ( many small molecules) are coiled
around each other. This arrangement is called a ‘double helix’.
ii) This sturcture can be compared with a coiled and flexible ladder.
Cell
Gene
Nucleus
of cell
cromosome
iii) In the structure of the nucleotide, a molecule of a nitrogenous base and
phosphoric acid are each joined to a molecule of sugar.
iv) There are four types of nitrogenous bases:
adenine, guanine, cytosine and thymine.
v) Adenine and guanine are called as ‘purines’
vi) while cytosine and thymine are called ‘pyrimidines’.
Ribonucleic acid (RNA) :
i) RNA is the second important nucleic acid of the cell.
ii) This nucleic acid is made up of ribose sugar, phosphate molecules and
nitrogenous bases.
iii) four types of adenine nitrogenous bases:
adenine, guanine, cytosine and uracil.
there are three types of RNA:
1. Ribosomal RNA (rRNA) :
i) The molecule of RNA which is a
component of the ribosome organelle
is called a ribosomal RNA.
ii) Ribosomes perform the function of
protein synthesis.
, 02.
2. Messenger RNA (mRNA) :
i) The RNA molecule that carries the
information of protein synthesis from
genes i.e. DNA chain in the cell nucleus
to ribosomes in the cytoplasm which
produce the proteins, is called
messenger RNA.
3. Transfer RNA (tRNA) :
The RNA molecule which, according to the
message of the mRNA carries the amino
acid up to the ribosomes is called transfer
RNA.
Science of heredity:
The science of heredity is useful for diagnosis, treatment and prevention of
hereditary disorders, production of hybrid varieties of animals and plants and
in industrial processes in which microbes are used.
Central Dogma: (protein synthesis process)
1) Information about protein synthesis is stored in the DNA and synthesis of
appropriate proteins as per requirement is necessary for body to grow &
development of orgen.
2) These proteins are synthesized by DNA through the RNA. This is calledm
as ‘Central Dogma’.
Transcription: (mRNA synthesis process)
1) Def: Process of mRNA synthesis from DNA by the help of DNA dependent
RNA polymerase II enzyme. This process is called as Transcription.
2) DNA dependent
DNA -------------------------------------> mRNA
RNA polymerase II enzyme
3) It present in nucleus.
