Metabolism
Metabolism is a body function which enables a cell to process and create needed organic compounds that will be used for cell processes like repairing, rejuvenating and energy.
Ecology, genetics and evolution are themes, subdisciplines and subtopics of biology -the study of life.
Explanation:
How Does Sensory Memory Work?
During every moment of your existence, your senses are constantly taking in an enormous amount of information about what you see, feel, smell, hear, and taste. While this information is important, there is simply no way to remember each and every detail about what you experience at every moment. Instead, your sensory memory creates something of a quick "snapshot" of the world around you, allowing you to briefly focus your attention on relevant details.
Types of Sensory Memory
Experts also believe that different senses have different types of sensory memory. The different types of sensory memory have also been shown to have slightly different durations.
Iconic memory, also known as visual sensory memory, involves a very brief image. This type of sensory memory typically lasts for about one-quarter to one-half of a second.
Echoic memory, also known as auditory sensory memory, involves a very brief memory of sound a bit like an echo. This type of sensory memory can last for up to three to four seconds.
Haptic memory, also known as tactile memory, involves the very brief memory of a touch. This type of sensory memory lasts for approximately two seconds.
Ans.
Sickle-cell disorder shows defected red blood cells, due to mutation in gene that code for hemoglobin. The mutated genes for sickle-cell disease are found in higher percentage of sub-Saharan African population as it provides protection against malaria as compared to population of United States.
Malaria is common in sub-Saharan Africa region and there, natural selection favored gene for sickle cells, because it might be beneficial to people having sickle cell disease that makes them able to survive in such condition and transmit their genes to offspring.
On the other hand, in those Africans, who moved to United States, where malaria is uncommon or absent, natural selection favored normal, wild type genes, resulting in fewer people with defected sickle cell.
Thus, the evolutionary process behind this is 'natural selection.'