Answer:
Las hormonas pertenecen al grupo de los mensajeros químicos, que incluye también a los neurotransmisores y las feromonas. A veces es difícil clasificar a un mensajero químico como hormona o neurotransmisor.
Todos los organismos multicelulares producen hormonas, incluyendo las plantas (En este último caso se denominan fitohormonas).
Explanation:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
Answer:
stigma
Explanation:
Pollination occurs when pollen grains from the anther land on a stigma. After pollen grains land on the stigma, a pollen tube grows from the pollen grain, through the style, and into the ovary. Sperm cells inside the pollen grain travel down the pollen tube and into the ovary which contains the ovules.
The correct answer would be A. The number of neutrons present in Krypton-82 would be 46. The atomic number of an atom represents the number of protons present while the mass number is the sum of the neutrons and protons in the atom. The mass number for the given atom is 82. So, 82-36 = 46 neutrons present.
