Answer:
A. the heterozygote advantage
Explanation:
Heterozygote advantage is the condition where the heterozygous individual has higher relative fitness than both homozygous dominant and homozygous recessive individual. This means that the heterozygote individual has higher chances of surviving than both the homozygous counterparts. Sickle cell anemia is a recessive inherited disorder in which oxygen carrying hemoglobin has an abnormal structure. Hence, the resultant RBCs are not spherical but have crescent sickle shape. The oxygen carrying capacity of such RBCs is drastically reduced but they are unaffected by malarial parasite due to their abnormal structure.
- A person with both the recessive genes for sickle cell would not be able to survive due to insufficient oxygen transport in body.
- A person with both the dominant genes would be free of sickle cell anemia but in case of malaria would not be able to survive as the normal RBCs would be hijacked by the parasite.
- A hetrerozygote would survive both in malaria and sickle cell condition since he has enough normal RBCs for oxygen transport but also has sickle cell RBCs which are unaffected by malarial parasite.
Answer:
Prokaryotes do not have introns, eukaryotes have introns
Explanation:
Prokaryotes do not have introns, eukaryotes do. Introns are regions of DNA that are transcribed but not part of the final protein. They interrupt exons, which are the coding parts of the gene. These are only present in eukaryotes.
Introns need to be removed before the mRNA can be translated into the protein sequence. This occurs by a process called splicing. The splicing machinery binds the junction between introns and exons and excises the intron. The exons are then fused together to create the mRNA.
Other processing steps occur to the eukaryotic pre mRNA to prevent it from being degraded in the cell. This includes adding a cap to the 5' end of the protein, and adding a poly A tail to the 3' end. One these steps are complete, the eukaryotic mRNA is complete.
The prokaryotic mRNA undergoes transcription and translation simultaneously because it doesn't require these processing steps.
Answer:
Option a) higher the average sea levels.
Explanation: Carbondioxide is also known as greenhouse gas. When carbondioxide concentration is higher in the atmosphere, it prevents the reflected sunlight from going into the atmosphere which increases the temperature of the surrounding air. This phenomenon is called global warming. This increase in temperature starts melting of ice which are present on mountains and thus, increases sea level.
