Evolution of different species in a given area starting from a point and spreading to other geographical areas is known as
Adaptive radiation
Natural selection
Migration
Migration
What is the figure given below showing in particular?
Ovarian cancer
Uterine cancer
Tubectomy
Tubectomy
In an area where DDT had been used extensively, the population of birds declined significantly because
birds stopped laying eggs
earthworms in the area got eradicated
cobras were feeding exclusively on birds
cobras were feeding exclusively on birds
The figure below is the diagrammatic representation o the E.Coli vector pBR 322. Which one of the given options correctly identifies its certain components(s)?
Ori- original restriction enzyme
rop-reduced osmotic pressure
Hind III, Eco RI-selectable markers
Hind III, Eco RI-selectable markers
The common bottle cork is a product of
dermatogen
Phellogen
Xylem
Xylem
B.
Phellogen
The cork cambium or phellogen cells divide periclinally cutting off cells towards the outside and inside. The cells cut off towards the outside become suberized and dead. These are compactly packed in radial rows without intercellular spaces and form cork or phellem. Cork is impervious to water due to suberin and provides protection to underlying tissues. The cells cutt off from cork cambium towards inside add to the cortex and are called secondary cortex cells or phelloderm cells.
Which part would be most suitable for raising virus-free plants for micropropagation?
Bark
Vascular tissue
Meristem
Meristem
Which one of the following is a wrong statement
Most of the forests have been lost in tropical areas
Ozone in upper part of atmosphere is harmful to animals
Greenhouse effect is a natural Phenomenon
Greenhouse effect is a natural Phenomenon
Common cold differs from pneumonia in that
pneumonia is a communicable disease whereas the common cold is a nutritional deficiency disease
Pneumonia can be prevented by a live attenuated bacterial vaccine whereas the common cold has no effective vaccine
Pneumonia is caused by a virus while the common cold is caused by the bacterium haemophilus influenzae
Pneumonia is caused by a virus while the common cold is caused by the bacterium haemophilus influenzae
Removal of RNA polymerase -III from nucleoplasm will affect the synthesis of
tRNA
rRNA
mRNA
mRNA