- Biology : The branch of science that deals with the study of living things.
- Branches of Biology
- Botany : The branch of biology that deal with plant life
- Zoology : Branch of biology dealing with animals .
- Plants : Primary producers of nature
- Flora : The plants of a particular region
- Fauna : The animals of a particular region
- The term Biology was coined by : Lamarck
- Father of Biology : Aristotle
- Father of Botany : Theophrastus
- Father of Zoology : Aristotle
- Father of modern biology : Charles Darwin
- Father of modern botany : Carl Linnaeus
- Father of molecular biology : Linus Pauling
- The term Species was coined by : John Ray
- The famous book of Aristotle : History of Animals
- The famous book of Theophrastu : Historia Plantum
- Father of Indian Botany : William Rosburgh
- The branch of biology which deals with the study of orgin of life : Abiogenesis
- The life originated from : Water
- The first successful experiment based on the orgin of life was done by : A.I Oparin(1932)
- Structural and Fundamental unit of life . All living organisms are made up of cells. The word cell is from the Latin word cellula.
- Cells are known as the building block of life .It was discovered and named by Robert Hooke (1665).
- The book ‘Micrographia’ was written by Robert Hooke.
- First to observe living cells such as bacteria, Protozoa and blood cells: Anton Van Leuwenhook.
Milestones in the history of cell biology
- Robert Brown : Discovered the centre of the cell and named it the nucleus(1831).
- M.T. Schleiden : Found out that the body of a plant is made up of cells(1838)
- Theodor Schwann : Found out that the body of an animal is made up of cells(1839)
- Rudolf Virchow : Observed dividing cells and inferred that new cells arise only from existing cells(1858).
- Study of cells : Cytology
- Study of tissue : Histology
- Cell Theory was formulated by M.J Schleiden and Theodor Schwann
- Scientist who modified cell theory : Rudolf Virchow
- The smallest cell : Mycoplasma(PPLO-Pleuro Pneumonia Like Organism)
- The largest cell : Unfertilized egg of ostrich
- The largest cell in human body : Ovum
- The smallest cell in human body : Sperm
- Longest cell in human body : Neuron(Nerve cell)
- The cell with longest lifespan in human body : Neuron
- The largest number of cell in human : RBC (Red Blood Cells)
- They are two types of cell:
- Prokaryotic cell
- Eukaryotic cell
- Prokaryotic cell : Cell without nucleus
- Eukaryotic cell : Cell with nucleus
Structure of the cell
- Cell wall : Outermost covering of the plant cell . It is made up of cellulose . It is a non living part of the cell.It is absent in animal cells.
- Cell membrane : Outermost covering of animal cell.
- All the components of a cell internal to the cell membrane.
- It is regarded as the Physical basic of life.
- The fluid living content of cell that consist of cytoplasm & nucleoplasm
- Cytoplasm : The portion of protoplasm without the nucleus.
- Ribosome : Protein synthesis is done by Ribosomes
- Endoplasmic Reticulum(ER) : It is known as Skeletal system of the cell.
- Brain of the cell
- All cellular activities are controlled by nucleus
- It is only found in eukaryothic cells
- Thread like units occurs in the cells during the time of cell division
- It is madeup of DNA and proteins.
- Chromosomes other than the sex chromosomes are called autosomes
- Number of autosomes in human cell is 44 (22 pair) and number of sax chromosomes are 2
- Nucleic acids : The two different nucleic acids found in the cells of every living organism- DNA and RNA
- DNA : Deoxyribonucleic acid (found in nucleus and mitochondria)
- RNA : Ribonucleic acid(found in cytoplasm)
- The structure of DNA was 1st deduced by Waston and Crick
- Golgi bodies :
- It is known as traffic police of the cell.
- It is the secretory organelle of the cell.
- The power house of the cell.
- It converts oxygen and nutrients in to energy.
- In mitochondria, the energy is stored in the form of ATP.
- ATP – Adenosine Triphosphate.
- ATP synthesis is takes places in Mitochondria.
- The universal biological energy currency of the cell:ATP.
- Lysosomes :
- Lysosomes are sac like structure bounded by a single membrane , known as suicidal bags
- The enzyme which is present in the lysosome is Hydrolytic enzyme.
- It is the digestive system of the cell
- Vacuoles :
- It is a fluid filled sac within a cell.
- In plant cells the vacuoles are large in size.
- Animal cells either do not have a vacuole or they have very small vacuoles.
- Plastids :
- Flat ,circular organelles found in plant cells
- Plastids are absent in animal cells.
Three types of plastids
- Chloroplasts : The green plastid found only in photosynthesis plant cells. It is known as the Kitchen of the cell.
- Leucoplasts : These are the white or colourless plastids
- Chromoplasts : These are coloured plastids which gives various colures to the flowers and
leaves of plants.
Exambles of chromoplasts
Cur cumin : Yellow color of the turmeric.
Lycopine : Red color of the Tomato.
Carotene : Orange color of Carrot.
- The process by which a parent cell divides into two or more daughter cells. Two types of cell division
- Mitosis : The cell division that takes place in plant and animal cells for the growth.
- Meiosis : The cell division that occurs in reproductive cells.
- Karyokinesis: Division of nucleus during cell division.
- Cytokinesis : Division of cytoplasm.