If the comet were to strike the planet, the impact energy would be about 300 times that of the asteroid collision that was thought to have caused the Cretaceous-Tertiary extinction that killed the dinosaurs about 65 million years ago.
Answer:
Is the benefit worth the cost?
Explanation:
Environmental policies application has to lead to some economic cost.
When coming up with this policies, the effect that this policies shall have towards environmental protection shall be considered.
The cost and economic effect that this policies shall cause should also be looked at.
If a policy causes insignificant change towards environmental protection and at the same time the costs are too high, then the policy should be dropped.
If a policy has got significant impact and costs less, the it should be taken.
Answer: SECONDARY CELL WALL.
Explanation: When cell wall grow,it becomes thickened,then it further deposits new layers of a different material (different from that of the primary cell wall) from where secondary cell wall is formed.
This secondary cell wall is made up of cellulose,hemicellulose,and lignin.
They function in providing additional strength,support, rigidity to cells and the larger plant.
Answer:
unicellular - both prokaryotes and eukaryotes
contain mitochondrion - eukaryotes only
are generally less than 2 pm - Prokaryotes only
multicellular - eukaryotes only
lack membrane-bound organelles - prokaryotes only
Explanation:
Prokaryotes are generally unicellular, that is, they are made up of single cells only. However, there are unicellular and multicellular eukaryotes with some eukaryotes like humans and advanced plants having as many as millions of cells.
Prokaryotes generally lack nucleus and other membrane-bound organelles such as chloroplast and mitochondrion. Eukaryotes on the other hand have nucleus and membrane-bound organelles such as mitochondrion and chloroplast.
When it comes to size, prokaryotes are generally small and microscopic while eukaryotes consist of both microscopic and macroscopic cells or organisms. However, prokaryotes are generally smaller than microscopic eukaryotes.
Answer:
The correct answer will be option-D.
Explanation:
In eukaryotes, the process of transcription takes place inside the nucleus whereas translation takes place in the cytosol. So, mRNA has to export to the cytosol from the nucleus.
Before export, the post-transcriptional modification takes place like 5' capping, 3' tailing and splicing mechanism.
The capping is done at 5' end by adding modified guanine (G) nucleotide which protects the mRNA from exonuclease activity and tailing is done at 3' end by adding adenine nucleotides which provides stability to the mRNA.Splicing removes the junk DNA called introns and joins the exons before export.
Thus, option-D is the correct answer.