Questions

Deep sea animals cannot produce food as there is no light. They have to depend upon the fall out of organic debirs raining down on them from surface layers. Hence they are detritivores.

The freezing point of water and melting point is 0 °C or 32 °F. The temperature may be lower if supercooling occurs.

Albedo refers to a material's ability to reflect sunlight. Since 30% of the sun's energy is reflected by the entire earth, the earth has an average albedo of 0.30.

Generally, dark surfaces have a low albedo and light surfaces have a high albedo.

All of the genetic information in a cell was initially thought to be confined to the DNA in the chromosomes of the cell nucleus.

It is now known that small circular chromosomes, called extranuclear, or cytoplasmic, DNA, are located in two types of organelles found in the cytoplasm of the cell.

These organelles are the mitochondria in animal and plant cells and the chloroplasts in plant cells.

Chloroplast DNA (cpDNA) contains genes that are involved with aspects of photosynthesis and with components of the special protein-synthesizing apparatus that is active within the organelle.

Mitochondrial DNA (mtDNA) contains some of the genes that participate in the conversion of the energy of chemical bonds into the energy currency of the cell—a chemical called adenosine triphosphate (ATP)—as well as genes for mitochondrial protein synthesis.