Biology MCQs

Notes:
Human sperm moves with the help of the Flagellum. The flagellum is primarily a motility organ that enables movement and chemotaxis.

Notes:
The vagina is a female reproductive organ that serves as the birth canal to allow the delivery of the fetus during labor.

Notes:
Azospirillum is an example of a loose association of nitrogen-fixing bacteria. Azotobacter is an example of Free-Living Nitrogen-Fixing Bacteria. Rhizobium is an example of Symbiotic Nitrogen-Fixing Bacteria. Blue-Green alga is an example of Symbiotic Nitrogen-Fixing Cyanobacteria.

Notes:
A transposon is a mobile genetic element. This is also known as jumping genes. A type of genetic material that can move around within a genome is called a mobile genetic element.

Notes:
The right pulmonary artery is longer and larger and runs horizontally outward in front of right main bronchus and behind the superior vena cava, to the base of the right lung where it divides in two branches. The left pulmonary artery is shorter and runs horizontally over the left upper division bronchus, to the base of the left hilum where it divides into two branches.

Notes:
The best food for the newborn baby is mother’s milk initial secretion call colostrum. Breast milk is free from contamination and adulteration and supplies necessary immunoglobulins and nutrients in almost correct amounts. It protects against allergies, sickness, and obesity. It protects against diseases, like diabetes and cancer. It protects against infections, like ear infections. It is easily digested – no constipation, diarrhea or upset stomach.

Notes:
Monocost and dicots differ in the location of stomata and shape of guard cells. In monocots stomata are Dumb-bell shaped in dicots they are bean-shaped.

Notes:
Biomagnification is the sequence of processes in an ecosystem by which higher concentrations of a particular chemical such as the pesticide DDT, are reached in organisms higher up the food chain. It’s principal cause is eutrophication of stagnant water leading to the increase in BOD level. The some biomagnifcation has led to the ban on the use of DDT as a pesticide.

Notes:
The clitellum is a thickened glandular and non-segmented section of the body wall near the head in earthworms and leeches, that secretes a viscid sac in which the eggs are deposited. Its main function is to store the eggs of the earthworm.

Notes:
An isogenic graft or Isograft is a graft between genetically identical individuals (i.e. monozygotic twins). This type of graft donot pose any form of tissue rejection threat by recipient’s body.