2) Cross-fertilization makes for more variation in the traits of plants, giving them immunities and resistances to weather, pests, and disease.
C. The Bering Land Bridge once connected what would be Russia and North America but the the movement of these continents separated the land bridge
The term for blue skin caused by lack of oxygen is cyanosis. One is said to be cyanotic when presenting with this discoloration.
Answer:
Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species
Explanation:
The competitive exclusion describes relationship between two species that compete for the limiting sources, and cannot coexist. It is enough for one species to have slightly advantage to be dominant over the other. As a consequence, other species (the weaker one) will be extincted (shift to a different ecological niche).
Answer:
<u>3) Uncontrolled cell division occurred as a result of gene mutations</u>
<u />
Explanation:
Spontaneous modifications within the genome may occur during the process of cell division. When copies of the DNA inside the cell are made, these mutations cause errors; and can include small single nucleotide polymorphisms, and large scale additions or deletions across multiple genes.
Some, like somatic mutations, exist only inside vegetative (body) cells, that cannot be passed onto offspring. This is caused by several factors like
- UV radiation,
- chemical mutagens,
- infective agents
UV radiation damages strands of DNA, by causing dimers to form; here, consecutive nucleotide bases covalently bond instead of those on the complementary strand. This conformational change causes errors in DNA proofreading and repair mechanisms where bases are not well-incorporated into the strand- tumors (clumps of uncontrolled cell growth) may form, resulting in melanoma, a type of skin cancer.