The Universe is defined to be the sum total of everything that we know about: stars, galaxies, clusters, superclusters, voids, etc.
Cosmology is the study of the structure and evolution of the Universe.
It is a subject of great current interest, as the Hubble Space Telescope and other new instruments have recently helped astronomers shed light on many important questions.
There have been many theories about the Universe, but they generally all share one fundamental postulate, the cosmological principle, which has two parts. First, the Universe must be isotropic (the same in every direction).
For example, the Hubble deep field images, extending 12 Gly away, for two completely different directions, are remarkably similar:
Answer:
The correct answer is (A) gene A is a positive regulator of gene B.
Explanation:
When positive regulation occurs a transcription factor is required to bind at the promoter in order to enable RNA polymerase to start transcription.
RNA means ribonucleic acid and it is a long single-stranded chain of cells that processes protein.
<span>There are many indicators for predator presence. Some of them are:
Being able to spot predator marks like scratches or fur.
Being able to feel predator movements.
</span><span>Echo-location </span>For example, moths respond to the echo-location calls from their bat predators; moths drop to the ground once they hear the sound pulse from the bat.
Answer:
C3 plants would have faster growth rates; C4 plants would be minimally affected.
Explanation:
C3 and C4 pathways are the variations of dark reactions of photosynthesis present in green plants. The photosynthetic efficiency of C3 plants is reduced due to the affinity of RuBisCo enzyme for oxygen which in turn leads to the futile pathway of photorespiration. RuBisCo enzyme catalyzes the rate-limiting reaction of the C3 pathway. On the other hand, the C4 plants concentrate CO2 around RuBisCo in their bundle sheath cells of leaves to minimize photorespiration and exhibit higher rates of photosynthesis.
Increased levels of atmospheric CO2 would reduce the photorespiration in C3 plants and would allow them to fix CO2 efficiently due to the increased concentration of CO2 around the enzyme RuBisCo. The increased photosynthetic efficiency would help these plants to exhibit faster growth rates.
However, the photosynthetic rate of C4 plants is not limited by CO2 concentration as they themselves reduce photorespiration by spatial separation of primary carboxylation in mesophyll cell and CO2 fixation in bundle sheath cells. Hence, increased CO2 levels in the atmosphere would not have any impact on their photosynthetic rate and growth.
