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This photo shows Drosophila that has normal antennae on its head, and a mutant that has legs on its head.
As seen in comparing the wild-type Drosophila (left) and the Antennapedia mutant (right), the Antennapedia mutant has legs on its head in place of antennae.

Evolution connection

Multiple alleles confer drug resistance in the malaria parasite

Malaria is a parasitic disease in humans that is transmitted by infected female mosquitoes, including Anopheles gambiae ( [link] a ), and is characterized by cyclic high fevers, chills, flu-like symptoms, and severe anemia. Plasmodium falciparum and P. vivax are the most common causative agents of malaria, and P. falciparum is the most deadly ( [link] b ) . When promptly and correctly treated, P. falciparum malaria has a mortality rate of 0.1 percent. However, in some parts of the world, the parasite has evolved resistance to commonly used malaria treatments, so the most effective malarial treatments can vary by geographic region.

Photo a shows the Anopheles gambiae mosquito, which carries malaria. Photo b shows a micrograph of sickle-shaped Plasmodium falciparum, the parasite that causes malaria. The Plasmodium is about 0.75 microns across.
The (a) Anopheles gambiae , or African malaria mosquito, acts as a vector in the transmission to humans of the malaria-causing parasite (b) Plasmodium falciparum , here visualized using false-color transmission electron microscopy. (credit a: James D. Gathany; credit b: Ute Frevert; false color by Margaret Shear; scale-bar data from Matt Russell)

In Southeast Asia, Africa, and South America, P. falciparum has developed resistance to the anti-malarial drugs chloroquine, mefloquine, and sulfadoxine-pyrimethamine. P. falciparum , which is haploid during the life stage in which it is infectious to humans, has evolved multiple drug-resistant mutant alleles of the dhps gene. Varying degrees of sulfadoxine resistance are associated with each of these alleles. Being haploid, P. falciparum needs only one drug-resistant allele to express this trait.

In Southeast Asia, different sulfadoxine-resistant alleles of the dhps gene are localized to different geographic regions. This is a common evolutionary phenomenon that occurs because drug-resistant mutants arise in a population and interbreed with other P. falciparum isolates in close proximity. Sulfadoxine-resistant parasites cause considerable human hardship in regions where this drug is widely used as an over-the-counter malaria remedy. As is common with pathogens that multiply to large numbers within an infection cycle, P. falciparum evolves relatively rapidly (over a decade or so) in response to the selective pressure of commonly used anti-malarial drugs. For this reason, scientists must constantly work to develop new drugs or drug combinations to combat the worldwide malaria burden.

Sumiti Vinayak, et al., “Origin and Evolution of Sulfadoxine Resistant Plasmodium falciparum ,” Public Library of Science Pathogens 6, no. 3 (2010): e1000830, doi:10.1371/journal.ppat.1000830.

X-linked traits

In humans, as well as in many other animals and some plants, the sex of the individual is determined by sex chromosomes. The sex chromosomes are one pair of non-homologous chromosomes. Until now, we have only considered inheritance patterns among non-sex chromosomes, or autosomes    . In addition to 22 homologous pairs of autosomes, human females have a homologous pair of X chromosomes, whereas human males have an XY chromosome pair. Although the Y chromosome contains a small region of similarity to the X chromosome so that they can pair during meiosis, the Y chromosome is much shorter and contains many fewer genes. When a gene being examined is present on the X chromosome, but not on the Y chromosome, it is said to be X-linked    .

Questions & Answers

what is ecology
Adeyemo Reply
what is zoology
zoology branch of biology that study animals
A plant is a living thing that grows in the earth and has a stem, leaves, and roots
Bello Reply
what is a plant
dalitso Reply
A plant is a living thing that grows in the earth and has a stem, leaves, and roots
a plant is an is a living thing that is classified under autothrops because it makes its own food through the process of photosynthesis .
what is plant
Odion Reply
Plants are autotrophic
Then animal are heterotrophic
what are organisms
Godfred Reply
Living structures
the diagram below show how the blood of a human embryo flows close to the mothers blood in the placenta . which substances are represent at x in higher concentrations than at y
Joyce Reply
what is ecology
Odion Reply
what is cell
what is cell
Is the basic unit of life
What is a cell
Awal Reply
What are tissues
A cell is the smallest unit of living organisms.
Tissues are group of similar cells performing a particular function.
how to pronounce the word cyanobacteria
siva Reply
Cyano then bacteria. look that "cyano" is just like "ciyano".
explain the term transpiration pull
Tank Reply
water is mainly " pulled" through the plant and that the driving force for this process is transpiration from the leaves .This is also referred to as the cohesion- tension -transpiration pull model transport.
what Is corona
My brother go and ask GOOGLE😷😷😷
Google it for the right answer. Corona is a virus which causes Novel Covid-19 disease that has been declared by WHO as a global or world pandemic.
Why is it called Covid-19?
jjwhat is. condinative system
condinative system is the system that harmonize all the. different. part. of. the. body and make. them function as a. specific unit
Describe the process of protein sythesis?
Kizito Reply
Ribosomes are responsible for protein synthesis in animals.
What is a ploidy level
Francis Reply
Ploidy refers to the number of chromosomes. We have 23 pairs of chromosomes in somatic cells. Sex cells are haploid thus 23 chromosomes vs. 46 Chromosomes.
Evolution is evolvement according to one's environment. Let's use humidity as an example. A person from a very cold environment would not be used to hot humid weather. But over time their body would slowly, slowly adapt.
Give me (3) types of biodiversity
Hi guys 🇧🇪
hello boy
what do you guys understand about evolution?
Kiana Reply
it's a process or analayzing some program
but am not sure if some know plz let share
is a study of
unfolding or unrolling hence the process of development of growth
is the periodic change of the structural features of an organism
I think
process of developing
hi guiz
hello guys
Evolution ~ Is the gradual change of development over time in which a new species are formed
Evolution is the sum total of adaptive changes that has existed before.
why are diagrams not available
Evans Reply

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