Answer:
Weeks.
Explanation:
Selective serotonin reuptake inhibitors are common antidepressants prescribed for patients with depression and anxiety disorders. However, these medications do not have an immediate effect. They usually have full effect within weeks, depending on the patient.
This delay, can be explained by the mechanism of action of these drugs. Selective serotonin reuptake inhibitors act by blocking the serotonin transporter which transports serotonin into the brain cells.This results in more being available outside the cells where it has it effects.
SSRIs don't work instantaneously because they do not target the transporter directly. They rather, bind to the DNAs that produce the transporter and therefore makes them less active and this leads to lower amount of transporters available. This process takes time.
Answer:
The complementary base pair is ATG TTT GTG ATA TGG CGC ATT TAC TAA
Explanation:
As per the complementary base pairing rule of DNA
C pairs with G and vice versa
A pairs with T (in DNA) or U (in RNA)
Breaking the given strand into triplets, we get -
TAC AAA CAC TAT ACC GCG TAA ATG ATT
ATG TTT GTG ATA TGG CGC ATT TAC TAA
Answer:
See explanations
Explanation:
Gregor Mendel developed the model of heredity that now bears his name by experiments on various charactersitics of pea plants: height (tall vs. Short); seed color (yellow vs. Green); seat coat (smooth vs. wrinkled), etc. The following explanation uses the tall/short trait. The other traits Mendel studied can be substituted for tall and short.
Mendel started out with plants that "bred true". That is, when tall plants were self-pollinated (or cross-pollinated with others like them), plants in following generations were all tall; when the short plants were self-pollinated (or cross- pollinated with others like them) the plants in following generations were all short.
Mendel found that if true breeding Tall [T] plants are crossed (bred) with true breeding short [t] plants, all the next generation of plants, called F1, are all tall.
Next, he showed that self-pollinated F1 plants (or cross- pollinated with other F1 plants) produce an F2 generation with 3/4 of the plants tall and 1/4 short.
A. 1/4 of the F2 generation are short plants, which produce only short plants in the F3 generation, if they are self- pollinated (or crossed with other short F2 plants;) these F2 plants breed true.
B, 1/4 of the F2 generation (1/3 of the tall plants) are tall plants that produce only tall plants in the F3 generation, if they are self-pollinated; these tall F2 plants breed true.
C. 1/2 of the F2 generation (2/3 of the tall plants) are tall plants that produce 1/4 short plants and 3/4 tall plants in the next [F3] generation, if they are self-pollinated. This is the same proportion of tall to short that F1 plants produce.
Answer:
Post reproductive isolation → Hybrid sterility
Explanation:
The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.
There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.
Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.
Postzygotic mechanisms or barriers include
- Hybrid inviability,
- Hybrid sterility,
- Hybrid decreased viability or fertility,
- Cytoplasmic interactions.
In the exposed example, it seems that the mountains separating the frogs´ populations made a place for the development of postzygotic barriers, specifically hybrid sterility. Frogs from one population get to mate and produce offspring with the frogs of the other population, but their progeny is sterile.
On day one the levels of oestrogen and progesterone are low, having dropped quickly at the end of the last cycle. Low oestrogen level causes FSH release from the pituitary gland.
