The genes in a population give forth the genetic variability across a population (genotypes). In addition, occasional mutations of these genes in a population increase this genetic variability. Hovever, natural selection only favours reproduction of individuals with genes that are favourable in the environment/habitat. Therefore, natural selection has no foresight but is rather pegged on being an ‘opportunistic’ process.
Innate: keratinized epithelium
stratified squamous epithelium hypodermal areolar connective tissue antigen presenting cells major histocompatibility complexes complement (antibody -dependent pathway )
Innate or non-specific response is the first defense against invaders. Components of this response include physical (e.g. skin . mucosa) and chemical barriers against pathogens and cells such as Natural Killer cells, macrophages, neutrophils, dendritic cells, mast cells, basophils, eosinophils. Innate response reacts immediately.
Adaptive: immunoglobulin plasma cells agglutinin
helper t cells memory t cells cytotoxic t cells cd4+cells
t lymphocytes
Adaptive immune response or specific response is specific to the pathogen presented and mediated by lymphocytes, B and T cells. Adaptive immune response creates immunological memory after the first, initial l response to a specific pathogen which leads to enhanced response.
Answer:
Plant Reproduction and Life Cycle. The life cycle of a plant is very different from the life cycle of an animal. Humans are made entirely of diploid cells (cells with two sets of chromosomes, referred to as ''2n''). ... Plants, however, can live when they are at the stage of having haploid cells or diploid cells.
Explanation:
In an animal life cycle, male and female parents each create sex cells (sperm and eggs) that unite to form a fertilized egg and develop into an offspring organism. Plants, likewise, have sperm and eggs in their life cycles, but these are produced by an intermediate stage between the adult and the offspring.
<span>A mirror neuron is a neuron that fires both when an animal acts and when the animal observes the same action performed by another. Thus, the neuron "mirrors" the behavior of the other, as though the observer were itself acting. Such neurons have been directly observed in primate species.</span>
