Answer:
The body has two lines of natural defense to protect against infection. The first are physical barriers, such as the skin, body secretions and mucous membranes. The second line of defense is the immune system. Specialized immune cells coordinate and execute attacks to kill germs that make it past the body's physical barriers.
The correct option is this: TWO DRAGONFLY SPECIES REGULARLY MATE BUT THEIR GAMETES ARE INCOMPATIBLE.
In biology, there are different types of reproductive barriers, one of these is prezygotic barrier. A prezygotic barrier is a kind of mechanism that prevent reproduction from occurring by blocking fertilization. In this case, the concerned species will be mating together, but their gametes will not be compatible and thus, zygote will not be formed.
A postzygotic barrier on the other hand is said to occur when the reproduction process is blocked after the formation of zygote or after fertilization has taken place. A good example of this is an hybrid mule that is sterile and can not reproduce.
Answer:
letter c po
Explanation:
sana po makatulong po sa inyo
Explanation:
Because meiosis creates cells that are destined to become gametes (or reproductive cells), this reduction in chromosome number is critical — without it, the union of two gametes during fertilization would result in offspring with twice the normal number of chromosomes.
Answer: D: When roots grow into cracks of rocks and expand the rock breaks.
