history and basic elements

1. Cell Theory
Cell Theory

2. What is “CELL THEORY”?
Cell theory states that the cell is the basic
unit of life; it is the smallest unit that is still
considered a living thing. The components of
a cell, organelles and molecules, are not
living.
According to the biology department of the
University of Miami, the key to cell theory is
the proposition that all living things are made
of cells. Every organism, no matter how
complex, is made up of an intricate system of
cells. Some organisms are unicellular,
comprised of a single cell.

3. HISTORY OF CELL
In the history first of all in 1665 the term
“CELL” was used by a scientist
“Robber Hook”.
He examine the lid of thermos with
microscope there he see some circles like
structures and fundamental units he called
them cells.

4. What is Cell?
Cell the basic structural and
functional unit of life of living
organisms.

5. SCHLEIDEN
He was the first scientist who
put forth the theory of Plant cell
. He was a botanist. He first time
said that plants are made up of
cells.

6. Schleiden’s plant cell

7. The first scientist who introduce the concept of
animal cell. He claims that animal’s body are
composed of tiny cells. He was the scientist who
laid the basic foundation of animal cell.
THEODOR SCHWANN

8. Schwan animal cell

9. Types and size of cell
• There are millions of different types of cells
with different structures, sizes, and jobs to do
in the body. Red blood cells carry oxygen in
the body, white blood cells destroy invading
organisms, and nerve cells send messages
throughout the body by sending electric and
chemical impulses.

10. Different cells

11. Q:What was Rudolf Virchow's
contribution to cell theory?
The German doctor Rudolf Virchow proposed that
1. All living organisms are composed of one or more
cells. (However, this is considered a controversy
because non-cellular life such as viruses are
disputed as a life form
2.The cell is the basic unit of structure and
organization in organisms.
3.Cells arise from pre-existing cells(that they are not
form by itself)

12. Structure of both cells

13. Difference in both cells

14. Cytoplasm
In cell biology, the cytoplasm is the material
within a living cell, excluding the cell nucleus. It
comprises cytosol (the gel-like substance
enclosed within the cell membrane) and the
organelles – the cell's internal sub-structures. All
of the contents of the cells of prokaryotic
organisms (such as bacteria, which lack a cell
nucleus) are contained within the cytoplasm.
Within the cells of eukaryotic organisms the
contents of the cell nucleus are separated from
the cytoplasm, and are then called the
nucleoplasm

15. Diagram

16. Classification of Cytoplasm
a.Metaplasmic
b.Protoplasmic

17. Metaplasmic
The Metaplasmic bodies are non
living parts of the cytoplasm. They
are either stored particles of food
or products of the activity of the
cell.

18. .
• Protoplasm is composed of a mixture of small
molecules such as ions, amino acids,
monosaccharides and water, and
macromolecules such as nucleic acids,
proteins, lipids and polysaccharides. They are
dead parts of the cytoplasm. They never form
newly but arises from division.

19. Function of nucleus
• The nucleus is an organelle found in
eukaryotic cells. Inside its fully-enclosed
nuclear membrane, it contains the majority of
the cell's genetic material. This material is
organized as DNA molecules, along with a
variety of proteins, to form chromosomes

20. Cell Division
• Cell division is the process by which a parent cell
divides into two or more daughter cells. Cell
division usually occurs as part of a larger cell
cycle. In eukaryotes, there are two distinct types
of cell division: a vegetative division, whereby
each daughter cell is genetically identical to the
parent cell and a reproductive cell division,
whereby the number of chromosomes in the
daughter cells is reduced by half to produce
haploid gametes.

21. Cell division

22. Amitosis
• a simple method of cell division (also called
direct cell division) which occurs without
formation of spindle fibres and appearance of
chromosomes (by 'appearance of
chromosomes', what I mean to say is that, the
chromatin network, which is initially present
in the form of long threads

24. Mitosis
• mitosis is a part of the cell cycle when
replicated chromosomes are separated into
two new nuclei

25. Mitosis

26. MELOSIS

28. GREGOR JOHN MENDAL
• Gregor Mendel, who is known as the "father
of modern genetics"

29. .

30. MANDAL’S EXPERIMENT
• his colleagues at the monastery to study
variation in plants. In 1854, Napp authorized
Mendel for the investigation, who conducted his
study in the monastery's (4.9 acres) experimental
garden ,which was originally planted by Napp in
1830.Unlike Nestler, who studied hereditary traits
in sheep, Mendel focused on plants. After initial
experiments with pea plants, Mendel settled on
studying seven traits that seemed to inherit
independently of other traits: seed shape, flower
color, seed coat tint, pod shape, unripe pod color,
flower location, and plant height. He first focused
on seed shape, which was either angular or
round.

31. .• . Between 1856 and 1863 Mendel cultivated
and tested some 28,000 plants, majority of
which were pea plants. This study showed
that one in four pea plants had purebred
recessive traits, two out of four were hybrid
and one out of four were purebred dominant.
His experiments led him to make two
generalizations, the Law of Segregation and
the Law of Independent Assortment, which
later came to be known as Mendel's Laws of
Inheritance.

32. Mandal’s Laws
• Law of Segregation of
genes
• Law of Independent
Assortment

33. Law of segregation
STATES THAT
During gamete formation, the alleles for each
gene segregate from each other so that each
gamete carries only one allele for each gene.

34. Law of independent assortment
• Genes for different traits can segregate
independently during the formation of
gametes

36. THEORY OF BLENDING
INHERITANCE

37. Blending Inheritance
• Many biologists and other academics held to the idea
of blending inheritance during the 19th century, prior
to the discovery of genetics. Blending inheritance was
merely a widespread hypothetical model, rather than a
formalized scientific theory (it was never formally
presented to a scientific body, nor published in any
scientific journals, nor ascribed to any specific person),
in which it was thought inherited traits were
determined randomly, from a range bound by the
homologous traits found in the parents. The height of a
person, with one short parent and one tall parent, was
thought to always be of some interim value between
its two parents' heights.

38. Shortcomings
• The shortcoming to this idea was in how it required the
person of interim height, in turn, to then become one of
the limiting bounds (either upper or lower) for future
offspring, and so on down the entire lineage. Thus, in each
family, the potential for variation would tend to narrow,
quite dramatically, with each generation, and, so it would
go for the entire population with every trait. If blending
inheritance were true, in this example, all members of a
species would eventually converge upon a single value for
height for all members. In short, "blending inheritance is
incompatible with obvious fact. If it were really true that
variation disappeared, every generation should be more
uniform than the previous one. By now, all individuals
should be as indistinguishable as clones.

39. It Fails to Describe
• Blending inheritance failed to explain how
traits that seemingly disappeared for several
generations often reasserted themselves
down the line, unaltered. Blue eyes and blond
hair, for example, often could disappear from
a family's lineage for several generations, only
to have two brown-haired, brown-eyed
parents give birth to a blond, blue-eyed child.
If blending inheritance were fact, this could
not be possible.