The right answer is B.
Cholera vaccination is only recommended for staff who have to intervene with patients in an epidemic situation. In all other cases, effective prevention is provided by good personal hygiene (washing hands) and food.
It is also important to know that this vaccine does not protect permanently: It protects only about 90% within 6 months, then to 50% within 3 years.
<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
The population of cactus dwelling birds will decrease and that of the animal they eat will increase.
Explanation:
When cacti is removed from the desert ecosystem, the birds that have their nest on the cacti will no longer have a home so they will migrate to other areas with favorable ecosystem.This will reduce the number of birds in this ecosystem.In turn, the animals that were feed by the birds will have the chance to multiply in numbers because a predator has been removed in the ecosystem.
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Keywords : Ecosystem, population
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