<span>Organism's habitat (where a species live) can be described as all of the biotic and abiotic factors in the area where an organism lives.
b. Ecological niche (how species live) is composed of all of the physical, chemical, and biological factors that a species needs to survive, stay healthy and reproduce. The niche includes food, abiotic conditions, and behavior.</span>
Lethal alleles cause the death of an organism prenatal or after the birth. Lethal alleles are usually a consequence of a mutation and they can be recessive, dominant or conditional. Since the lethal dominant alleles are harmful whether they are carried in homozygous (e.g.AA) or heterozygous (e.g.Aa) form, a strong selection against them is present and thus these alleles are much more rare.
They are specialised cells.
Osler's nodes are split pea–sized, erythematous, tender nodules located principally on the pads of the fingers and toes. They are few in number at any given time and occur in about 15% of patients with subacute bacterial endocarditis.
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