Biological specificity

Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features.

The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera Homo (humans) and Pan and in standard usage excludes the genus Gorilla (gorillas).

Apolipoprotein E (Apo-E) is a protein involved in the metabolism of fats in the body of mammals. A subtype is implicated in the Alzheimer's disease and cardiovascular diseases. It is encoded in humans by the gene APOE.

Chromosome 19 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 19 spans more than 61.7 million base pairs, the building material of DNA. It is considered the most gene-rich chromosome containing roughly 1,500 genes, despite accounting for only 2 percent of the human genome.

Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation, mood swings, loss of motivation, self-neglect, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years.

In the fields of sociology, social ontology, and communication theory, social constructionism proposes that certain ideas about physical reality arise from collaborative consensus, instead of the pure observation of said physical reality. The theory of social constructionism proposes that people collectively develop the meanings of social constructs. Social constructionism has been characterised as neo-Marxian theory and as a neo-Kantian theory, proposing that social constructionism replaces the transcendental subject with a societal concept that is descriptive and normative.

Gender includes the social, psychological, cultural and behavioral aspects of being a man, woman, or other gender identity. Depending on the context, this may include sex-based social structures and gender expression. Most cultures use a gender binary, in which gender is divided into two categories, and people are considered part of one or the other ; those who are outside these groups may fall under the umbrella term non-binary. Some societies have specific genders besides "man" and "woman", such as the hijras of South Asia; these are often referred to as third genders. Most scholars agree that gender is a central characteristic for social organization. Gender can be thought of as biopsychosocial, as it includes social, psychological, biological, cultural and behavioral aspects.

Interspecific competition, in ecology, is a form of competition in which individuals of different species compete for the same resources in an ecosystem. This can be contrasted with mutualism, a type of symbiosis. Competition between members of the same species is called intraspecific competition.

In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species, or of different species. These effects may be short-term, or long-term, both often strongly influence the adaptation and evolution of the species involved. Biological interactions range from mutualism, beneficial to both partners, to competition, harmful to both partners. Interactions can be direct when physical contact is established or indirect, through intermediaries such as shared resources, territories, ecological services, metabolic waste, toxins or growth inhibitors. This type of relationship can be shown by net effect based on individual effects on both organisms arising out of relationship.

Intraspecific competition is an interaction in population ecology, whereby members of the same species compete for limited resources. This leads to a reduction in fitness for both individuals, but the more fit individual survives and is able to reproduce. By contrast, interspecific competition occurs when members of different species compete for a shared resource. Members of the same species have rather similar requirements for resources, whereas different species have a smaller contested resource overlap, resulting in intraspecific competition generally being a stronger force than interspecific competition.

In biology, an organism is any living system that functions as an individual entity. All organisms are composed of cells. The idea of organism is based on the concept of minimal functional unit of life. Three traits have been proposed to play the main role in qualification as an organism:noncompartmentability – structure that cannot be divided without its functionality loss, individuality – the entity has simultaneous holding of genetic uniqueness, genetic homogeneity and autonomy, distinctness – genetic information has to maintain open-system.

Sperm precedence, also known as sperm predominance, is tendency of a female who has been bred by multiple males to give birth to their offspring in unequal proportions. Sperm precedence is an important factor in the sperm competition.