The correct answer would be D. Mollusca.
The question is basically describing a snail.
Arthropoda have segmented bodies.
Echinodermata(starfishes, sand dollars etc.) are radially symmetrical.
Also none of them have shells except phylum Mollusca :)
The frequency of the recessive allele for the Hbs gene when there is an outbreak of malaria will increase.
The sickle hemoglobin is produced by the HbS gene, a variation of the B-globin gene. A person who possesses two recessive alleles is said to have the genetic condition known as sickle cell anemia.
People who are heterozygous have the advantage of having normal and sickle hemoglobin, so they are more resistant to malaria because malaria will only act on normal hemoglobin, increasing the prevalence of the recessive allele of the HbS gene.
However, the malarial parasite only affects hemoglobin which is normal, making heterozygous people more resistant to the disease. Hence, the frequency of the recessive allele for the Hbs gene when there is an outbreak of malaria will increase.
To learn more about malaria refer to:
brainly.com/question/3895081
#SPJ4
The secondary survey or assessment is performed once the primary survey is done and non-life threatening injuries can be evaluated. While performing this kind of assessment it is essential for the clinician to obtain as much information as possible so that one can properly diagnose the injured person.
In the secondary assessment, the healthcare expert goes via step by step from head to toe to determine what has happened. This can involve and is not restricted to inspection, soft tissue and bony palpation, circulation, special tests, and neurological. Secondary assessment is done to find out the cause of injury, how the injury took place, and how severe is the injury.
Answer: Soil moisture and fertility
Cheat grass is likely to decrease the soil moisture of the region, thus rendering the soil infertile and unfit for other plants growth.
Explanation:
Cheatgrass is an exotic weed native to Europe, West Asia and Northern Africa. Cheatgrasses outcompeted native vegetation as a result of large number of livestocks like cattle and sheep into sagebrush region. The livestocks overgrazed on native vegetation, which resulted to a void filled rapidly by Cheatgrass.
Cheatgrass grows on pastures, hills, and ranges. Wildfires promote more Cheatgrass but destroy native plants vegetation. Cheatgrass can survive drought due to deep root system they possess. The deep root system make the plant to grow and flourish with even small amount of water. Its deep root system reduce soil moisture and deplete soil fertility, preventing the growth of other plants. Also, Cheatgrass is self germinating and require les soil to grow. All these attributes that favor Cheatgrass have threatened native plants such as sagebrush plants and woodlands.
