Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell's ribosomes (the structures in which protein synthesis takes place); and transfer RNA (tRNA) molecules carry amino acids to the ribosomes during protein
Answer:
True.
Explanation:
The earth system is itself an integrated system, but it can be subdivided into four main components, sub-systems or spheres: the geosphere, atmosphere, hydrosphere and biosphere. These components are also systems in their own right and they are tightly interconnected.
Answer:
Declining crude birth rates.
Explanation:
Birth rate may be defined as the number of births takes place per year per thousand of the population. The birth rate and death rate may change the population dynamics.
The developing countries shows the expanding population graph as they have more number of people of the reproductive age. The advancement in the medical field results in the decline birth rate that causes the decline of the nature resources.
Thus, the answer is declining crude birth rates.
Answer: D is wrong
Explanation: gametes are haploid. The haploid number in humans is 23. The diploid number is 46.
Answer: D). Primary species have large numbers of offsprings, and climax communities contain species that have small numbers of offsprings.
An ecological succession is a process of gradual changes occurs in a biological community with respect to changes in the non-living abiotic factors (water, air and sunlight) and with respect to time until the ecosystem attains stability. Primary or pioneer species are the species which invade the previously barren and primitive landmass for their survival. These species make the environment suitable for the growth of other species. These grow and develop in the initial stages of succession. These species are simple organisms which reproduce asexually and produces large number of offsprings. Examples are lichen and moss. Lichen grows on the surface of rocks and acids released by them causes withering of rocks into soil which facilitate the growth of mosses and other plants. Climax community develops in an ecosystem after replacing many previously inhabiting species. Climax community develops in the end of the ecological succession. It contains species which are highly complex and uses sexual reproduction for the production of offsprings which are less in number as compared to those produced by pioneer species by asexual reproduction.
