<span>I'm assuming this in plants.
Brief-ish answer:
"Fertilization in plants occurs when pollen grains are transported from anthers to stigma. When ripe pollen from an anther catches on the stigma of the same kind of flower, each pollen grain sends out a small thread-like tube."
Here's a fuller answer:
"</span>Fertilization occurs after pollination, when pollen grains land on the stigma of a flower of the same species. During this time, a series of events take place leading to the formation of seeds. A pollen grain on the stigma develops a tiny tube that runs down the style of the ovary. The pollen tube contains a male gamete which meets the female gamete in the ovule. Fertilization occurs when the two gametes combine and their chromosomes join. The resulting product is a normal complement of chromosomes, with some from either parent flower. The fertilized ovule forms a seed, which consists of a food reservoir and an embryo that later develops into a new plant. In gymnosperms (conifers) male gametes are enclosed in pollen grains and are transmitted by wind or insects to the female reproductive organs. Fertilization in angiosperms (flowering plants) occurs when insects or other animals transport the pollen to the female reproductive organ (pistil).<span>
</span><span>Fertilization is the fusion of gametes to launch the development of a new individual organism. In animals, the process entails the combination of ovum with a sperm, leading to the development of an embryo. Fertilization in plants occurs when haploid gametes meet to create a diploid zygote, which eventually forms an embryo.</span><span>"
source: </span>https://www.reference.com/science/plant-fertilization-occur-ccf48c80e72fc410
Answer:
synapse
Explanation:
We know that nerve impulses, signals, must pass from cell to cell for a response to a given signal to occur. For this to happen, the presence of a specialized region called the synapse is required. Synapse is the structure that allows signals to be transmitted from one nerve cell to another.
Synapse can be defined as the region of proximity between the end of a neuron and a neighboring cell, where nerve impulses are transformed into chemical impulses due to the presence of chemical mediators.
Answer:
Several 2',3'-dideoxy-3'-thiapyrimidine nucleosides were studied for their ability to inhibit hepatitis B virus (HBV) DNA replication in a HBV-transfected cell line (2.2.15). 2',3'-Dideoxy-3'-thiacytidine (SddC) and 5-fluoro-2',3'-dideoxy-3'-thiacytidine(5-FSddC) were found to be the most potent anti-HBV compounds of those examined. Both compounds resulted in nearly complete cessation of viral DNA replication at 0.5 microM, as monitored by the absence of both intracellular episomal and secreted viral DNAs. The HBV-specific RNAs were not reduced at concentrations that completely blocked HBV DNA replication, suggesting that the inhibitory target is HBV DNA synthesis. The antiviral action of SddC and 5-FSddC was reversible. The concentration of SddC and 5-FSddC required to inhibit 50% of 4-day cell growth in culture was 37 microM and more than 200 microM, respectively. Unlike 2',3'-dideoxycytidine, these two compounds do not affect mitochondrial DNA synthesis in cells at concentrations lower than that required to inhibit cell growth. In view of the potent and selective antiviral activity, both SddC and 5-FSddC should be further evaluated for the treatment of human HBV infection.
Explanation:
Alcohol can pass directly into the bloodstream from the mouth or stomach is a true statement.
On consumption of alcohol it travels from mouth to stomach, then into the circulatory system, kidney, liver, lungs and brain. Alcohol being a small molecule does not need any digestion in stomach and passes to the bloodstream directly in an empty stomach. When food is present in stomach, the absorption rate is reduced but is not stopped.
Once the alcohol is in the bloodstream, it gets evenly distributed throughout the body.
