Answer: Organ systems:
they work together to carry out a particular function for the organism.
Explanation:
Answer:
in the wall of the right atrium of the heart.
Explanation:
The sinoatrial node (SA), consisting of spindle-shaped cells, initiates the electrical activity of the heart. From its location in the right atrium in proximity to the superior vena cava, the electrical activity spreads to the atria, whose cells are larger than those of the SA.
Answer: Option (1)
Explanation:
The extinction event played an important role in the creation of new diverse life forms on earth. After an extinction event, both globally and locally, more than 75% of animal species gets vanish and the only those highly resistant life supporting organisms survive and with due course of time, they undergoes evolution, thereby bringing changes to the existing life forms. This is how they initiates and helps in the increasing species diversity.
Thus, the correct answer is option (1).
It eliminates certain genetic diseases or bad traits for the flock.
