It’s actually bacterial DNA
Answer:
The correct answer is D. proliferation and differentiation.
Explanation:
Primary immune response occurs due to the first exposure of an antigen to the immune system. The primary immune response is generally delayed by many days because it takes time for B and T cells to become cloned and to proliferate and differentiate.
Then after several days of proliferation and differentiation of activated T and B cells, T cells become effector T cells and B cell becomes plasma cells which then eliminates the antigen. Memory B and T cells are also produced during this process which helps in generating a quick immune response during the second and subsequent exposure of that antigen.
So the correct answer is D. proliferation and differentiation.
Descending limb of loop of Henle
It helps to maintain the concentration of urine. It is highly permeable to water thus water is readily reabsorbed from the descending limb by osmosis. It is impermeable to sodium and chloride ions.
<h3>What is a Tubule system ?</h3>
The transverse tubular system is a network of interconnecting rings, each of which surrounds a myofibril
- The nephron uses four mechanisms to convert blood into urine: filtration, reabsorption, secretion, and excretion. These apply to numerous substances
- The distal convoluted tubule (DCT) and collecting duct (CD) are the final two segments of the kidney nephron. They have an important role in the absorption of many ions, and in water reabsorption.
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These genes could have arisen by gene duplication.
<h3>What is gene duplication?</h3>
Gene duplication is the process of copying a section of DNA that codes for a gene. A retro transposition event or a recombination mistake are both potential causes of gene duplication. As a result, the duplicate gene coding may experience a significant number of modifications throughout time. This might prevent the gene from functioning or, in other situations, give the creature a benefit.
Gene duplication is a phenomenon that can happen through a variety of ways:
- Ectopic Recombination: Uneven crossing-over between misaligned homologous chromosomes during meiosis might result in duplications. A duplication at the exchange site and a reciprocal deletion are the results of this recombination.
- Replication Slippage: Short genomic sequences can be duplicated as a result of the replication error known as replication slippage. DNA polymerase starts copying the DNA during replication, but eventually the polymerase separates from the DNA, causing replication to stall. The replicating strand is incorrectly aligned when the polymerase reattaches to the DNA strand, which accidentally results in several copies of the same portion.
- Aneuploidy: When a single chromosome's nondisjunction causes an abnormally high number of chromosomes, this condition is known as aneuploidy. Aneuploidy is frequently damaging and frequently causes spontaneous miscarriages in mammals. Some aneuploid people can survive. For instance, human trisomy 21 causes Down syndrome but is not lethal.
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CO2 molecules can vibrate in ways that simpler nitrogen and oxygen molecules cannot, which allows CO2 molecules to capture the IR photons. Greenhouse gases and the greenhouse effect play an important role in Earth's climate.