Sixth Second Term-Science(English)

Cell Structure:
1.The human body is made up of several small units called cell.
2.Cell is the basic&fundamental units of living organism.
3.Cell is discovered by Robert Hooke(1665).
4.In latin cellula means small chamber.
5.Bricks on the wall are similar to Cell of an onion peel.
6.Cell is a small factory of 12 to 13 organelles.
7.Plant and Animal have different type of cell.
8.A cell that does not contain membrane bound organelles is called prokaryotic cell (Eg. Bacteria).
9.A cell that contain well defined membrane bound organelles is called eukaryotic cell(Eg. Animal cell,Plant cell).
10.Plant&Animal cells are Similar in their basic organisation.

Note:Instead of plastids in plant cell, animal cell have centrosome.

Animal cell:
11.plasma membrane envelope the cell and gives shape to the cell.
12.Plasma membrane controls the entry&exit of material.
13.Protoplasm is a colloid found inside plasma membrane.
14.Protoplasm contains two component of cell namely Cytoplasm&Nucleus.
15.J.E.Purkinjee coined the term Protoplasm.
16.Cytoplasm is located between plasma membrane & nucleus.
17.Cytoplasm is made up of Proteins&Carbohydrates.
18.Organelles&lipid droplets are present in cytoplasm.
19.Nucleus(Spherical)is the control centre of cell.
20.Nucleus carries genetic characters from generation to generation.
21.Mitochondria is the power house of cell.
22.Mitochondria involves in cell respiration&Oxidation.
23.Golgi bodies is a tabular structure which involves in secretion of digestive enzymes&formation of  lysosomes.
24.Golgi bodies seperates protein from ingested food.
25.In plant cell Golgi bodies are called dictyosomes.
26.Endoplasmic Recticulum helps in transportation of material from one part of cell to another.
27.Ribosomes are called Protein factory of cell(Granular structure).
28.Lysosomes are spherical yellow shaped bodies which helps in cell protection.
29.Lysosomes is called Sucidal bags of cell(Destroys pathogens).
30.Centrosome  looks likes a stick&found near the nucleus.
31.Centrosome plays a important role in Cell Division.
32.Vacuoles is light blue in colour&appears like bubble.
33.Vacuoles maintains intracellular pressure.

Plant Cell:
34.Plant are more rigid than animal due to the presence of Cell Wall.
35.Cell Wall protects the inner organs.
36.Plastids contains pigments.
37.Human body have 6 crore&50 lakh cells.
38.Bones are made up of special type of dry cell.
39.Red Blood Cell was discovered by Anton Van Leeuwenhoek.
40.In animals Nerve cell is the longest cell& Bone Cell is the toughest cell.
41.Chloroplast is a green pigment which gives colour to stem&leaves.
42.Chromoplast is a orange adn yellow pigment whi gives colour to flower&fruits.
43.Leucoplast is colourless found in root&underground Stem.

Points to Remember:

• Golgi bodies are tabular structure.
• Ribosomes are granular structure.
• Lysosomes are spherical shaped and yellow in colour.
• Centrosomes are stick like structure.
• Vaucoles are light blue in colour.

Seperation of substances:
1.Solid seperation methods are Hand picking,Winnowing,Seiving and Magnetic Seperation.
2.Liquid seperation of insoluble substances are sedementation,decantation and filteration.
3.Liquid seperation of soluble substances are evaporation and condensation.

Energy:
1.Energy is the ability or capacity to do work.
2.Unit of energy is joule.