Sodium ions are “pumped” from a region of lower concentration to a region of higher concentration in the nerve cells of humans. This process is an example of
A. Diffusion
B. Passive transport
C. Osmosis
D. Active transport
Biology
It is possible to date the rocks by comparing the amount of specific radioactive isotopes they contain. Which of the statement is correct in this respect?
A. Older sediment layers have equal amount of these radioactive isotopes as that of the young ones
B. Older sediment layers have less amount of these radioactive isotopes as that of the young ones.
C. Older sediment layers have greater amount of these radioactive isotopes as that of the young ones.
D. Older sediment layers did not have these radioactive isotopes
Normally, in the process of osmosis, the net flow of water molecules into or out of the cell depends upon differences in the ?
A. Concentration of water molecules inside and outside the cell
B. Concentration of enzymes on either side of the cell membrane
C. Rate of molecular motion on either side of the cell membrane
D. None of these
The concept that various organisms dominated this planet during various geological time period and thus placing organisms in a time squence came from the studies by ?
A. Environmental biologist
B. Paleontologist
C. Marine biologist
D. Social biologist
Most cell membranes are composed principally of ?
A. DNA ad protein
B. Protein and Lipids
C. Protein and Chitin
D. Protein and RNA
Most cell membranes are composed principally of ? Read More »
A large regional community primarily determined by climate is called ?
A. Population
B. Community
C. Biome
D. Habitat
A large regional community primarily determined by climate is called ? Read More »
Which of the following pathogen type cause disease that can be treated with antibiotics ?
A. bacteria
B. fungi
C. virus
D. none of these
Different species of plants and animals living in the same habitat is called?
A. Population
B. Community
C. Biome
D. Habitat
Different species of plants and animals living in the same habitat is called? Read More »
The evaporative cooling in the respiratory tract of dogs is called?
A. Vasodilation
B. Vasoconstriction
C. Panting
D. All of these
The evaporative cooling in the respiratory tract of dogs is called? Read More »