There is no A and B antigen on RBC of “O^–”blood group, So O, Rh^– is known as universal blood donor.

Achievement                                                                                              Scientist
A. Discovery of transduction and conjugation in bacteria          –              3. Lederberg
B. Establishing the sex linked inheritance                                  –               4. Morgan
C. Isolation of DNA Polymerase from E. coli                            –                2. Kornberg
D. Establishing the complete genetic code                                 –                1. Khurana

Double helix structure of DNA contains 2 complementary strands which transmits genetic transmits information from generation to generation.

Metastasis is the spread of cancer from its primary site to other places in the body (i.e. brain, liver). Cancer cells can break away from a primary tumour, penetrate into lymphatic and blood vessels, circulate through the blood stream and grow to a normal tissues in the body.

Ptyalin – It is present in saliva that catalyzes the hydrolysis of starch into maltose and dextrin.
Pepsin – It is an enzyme released in stomach that degrades food proteins into peptides.
Renin – It is an enzyme that is present in kidney and converts angiotensinogen into angiotensin balancing sodium and potassium level in blood.
Oxytocin – It induces contraction of smooth muscles.

Antigen is a foreign molecule, which invade the body of organism, and induce immune response to stimulate antibody/generation/production.

Ribosome and Endoplasmic reticulum are main sites for protein synthesis. Ribosome, which serve as staging area where some RNA helps in protein synthesis. Endoplasmic reticulum is an irregular, double membrane network scattered in cytoplasm, also helps in protein synthesis.

• Apoptosis is the process of programmed cell death in multicellular organisms. Apoptosis occurs during normal cell turnover, development and in immune system.
• Ageing is the accumulation of changes.
• Degeneration is the deterioration of a tissue or an organ in which its function is diminished or its structure impaired.
• Necrosis is the cellular death without any programming.

Breast bone – Sternum
Collar bone – Clavicle
Knee Cap – Patella
Shoulder Blade – It connects the humerus (upper arm bone) with the clavicle. It is known as scapula.

• Tape worms are hermaphrodite (both male and female reproductive organ present).
• Round worms are unisexual (separate sex).
• Filaria is caused by Wuchereria bancrofti which is a parasitic nematode.
• Guinea worm is a long and very thin nematode, not an annelid.

In organic evolution, Lamarck believed that any particular part of the body that is put into more frequent use, has tendency to develop stronger and better while that part of body which is put into less or no use has tendency to gradually disappear. So, loss of limbs in snake is an example of use and disuse of organs.

• Polyploidy occurs in cells and organisms when there are more than two paired (homologous) set of chromosome founds which controls more than one characters simultaneously.
• Apomixis is the process of asexual reproduction in which the embryo grow from egg cells without being fertilized.
• Pleiotropy occurs when a single gene influences multiple phenotypic traits.
• Polytene is a giant chromosomes found in some two-winged flies.

• Testes of man produce hormone testosterone and progesterone hormone is secreted by ovary of woman.
• Adrenal hormone releases the hormone cortisol.

Foot and mouth disease in animals (hoof and mouth disease) is a viral infection affecting cloven hoofed domestic and wild animals. The viruses belong to the family picornaviridae.

(Indian wild life species)                       (Scientific names)
Asiatic wild ass                            –         Equus hemionus
Barasingha                                   –         Cervus duvauceli
Chinkara                                       –        Gazella gazella
Nilgai                                            –        Boselaphus tragocamelus

Wolf is monogamous. Monogamous is the organism which has only one spouse and mate at any one time.

The sexes are separate except few echinoderm species. There is no sexual dimorphism. Fertilization is external and few forms are viviparous.

Scientist                                                   Achievementes
A. Arber and Smith                                  2. Discovered endonuclease
B. Feldman                                               1. Developed transgenic plants with Agrobacterium T-DNA
C. Mullis                                                   4. Discovered polymerase chain reaction.
D. Temin & Baltimore                              3. Discovered reverse transcriptage

• Viroids are plant pathogens that consists of a short stretch of highly complementary, circular, single-stranded RNA molecule.
• Prion is an infectious agent composed primarily of protein.
• Mycoplasma is a genus of bacteria that lack of cell wall.
• Rickettsias possess cell wall.

Urination can be induced within some minutes after a person consumes alcohol, because when the kidney filters the waste, the capillaries constricts and affects the filtering ability of kidney. When the body needs to conserve water, the pituitary gland excretes a hormone called vasopressin, which causes the nephron filters to become permeable retaining more water in the blood stream and allowing less water to be excreted in the urine. Alcohol decreases vasopressin secretion.