NCERT solutions for Science

  NCERT Solution > Class 8  > S cience Chapter 9 .   Reproduction in animals. Question 1.  Explain the importance of reproduction in organism ?  Answer - Reproduction process shows following benefits-  1. It maintain the continuity of life so that they become safe from life. 2. Dead organism due to disease ,aging ,growth are replaced by new organism 3. Due to different combination variation takes place in the organism and new characters are produced. 4. Variation and features are transferred from one generation to the next generation. 5. To maintain the existence of organism 6. It increases the number of cells  and organisms. 7. Replication of DNA takes place and hereditary characters are transferred from one generation to the next generation. Question. 2.  Describe the process of fertilization in human beings? Answer- 1. In human being the fertilization process is internal it takes place inside the female body. 2. Fertilization means U...

 Biology > cell the unit of life > class 11th What is cytoplasm explain its function Definition- " The space present between the nuclear membrane and plasma membrane is filled with translucent Jelly like fluid is called as cytoplasm" . 1. It includes all cell organelles except nucleus. 2. It consists of various inorganic molecules such as water, salt of Na and K metals ,carbohydrates, lipids ,proteins ,nucleoprotein ,nucleic acid and a variety of enzymes. 3. Cytoplasm divides into two parts hyaloplasm and trophoplasm .It is also called as cystol. Hyaloplasm-  It is made up of non living material a) Reserved material- carbohydrate, proteins b) secretary material - enzymes ,nectaries c) Excretory material -Tandon resins , essential Oil, gum ,latex, mineral ,crystal etc. Trophoplasm It is a living part cell organelles contain endoplasmic reticulum and Golgi body, chloroplast ,mitochondria ,ribosomes , plastids ,microbodies, microtubules cilia and flagella. Note - put your ...

 Biology > cell the unit of life - plasma membrane > class 11 Plasma membrane/ cell membrane/ biomembrane Each cells of plant and animal  are covered by a thin membrane is called plasma membrane. It is composed of protein lipid and carbohydrates 20-40% part made up of protein it is of three layers structural protein made up backbone of the membrane and enzymatic protein made the specific function of the membrane and carrier protein help to the movement of substance  accross the plasma membrane. Lipid made 60-80%   part of plasma membrane . Carbohydrate made 1-5 of plasma membrane. Sandwich / Danielli Davson model According to this model biomembrane is made up of two layers of protein and the layers of lipid present in between the protein. layer it just looked like a sandwich lipid is of two polar in rounded hydrophilic end or water loving  while other non polar or hydrophobic tail part or water hating end. 1. Outermost layer of protein is 20 A o thick...

NCERT solutions of class 8 >Science > Chapter 8 - Cell structure and functions  NCERT Solution //class 8// Science // Chapter 8-  Cell structure and functions 1 .   Indicate whether the following statements are true or false a)  Unicellular organisms have one -celled body.     Answer. - True b) Muscle cells are branched Answer. -True c) The basic living unit of an organism is an organ Answe r-. False d) Amoeba has irregular shape Answer . True   2. Make a sketch of human nerve cell what function do nerve cell perform?  Answer .        Function of nerve cells-  Nerve cell carry the signal of sensation from different body parts to brain or  it again carry the reverse signal from brain to other body parts. 3. Write a short notes on following  a) Cytoplasm -             The space present between the nuclear membrane and plasma membrane is filled with the translucent ...