Answer:
The mass number of an atom is its total number of protons and neutrons. Atoms of different elements usually have different mass numbers , but they can be the same. For example, the mass number of argon atoms and calcium atoms can both be 40.
Explanation:
Answer: The great molecular biologist and Nobel laureate Francois Jacob has stated that the human brain has a built-in need for order. From earliest times, human beings looked out and recognized cycles, repetitive patterns in nature—day following night, the seasons, tides, lunar cycles, plant succession, animal migration—that conferred the ability to predict their recurrence, and thus people acquired a semblance of understanding of and control over the cosmic forces impinging on their lives.
Explanation: can i have brainliest pls
Answer:
<em><u>D. The first flowering plants were introduced toward the end of the Mesozoic era.</u></em>
<em><u /></em>
Explanation:
Following the Paleozoic Era, the Mesozoic Era or <em>Age of Conifers</em> began approximately 250 million years ago. This major geological era brought about the ancestors of many of the plant and animal groups still in existence today.
The Mesozoic era is marked by 3 divisions:
- the Triassic Period,
- the Jurassic Period,
- and the Cretaceous Period.
Animals and plants slowly recovered after the mass extinction in the Permian-Triassic extinction that led to the eradication of most aquatic marine species. They evolved to exploit varying niches in their environment, leading to a boom in terrestrial animals. Over time the planet's increasingly warm climate, abundant in atmospheric oxygen and carbon dioxide, contributed to the growth of diverse megaflora, that rapidly dominated the planet's terrestrial biosphere.
By the end of the <em>Mesozoic Era</em>, in the Cretaceous period, flowering plants (angiosperms) largely replaced the dominant seed ferns of the <em>Triassic</em>, and the conifers, cycads and gymnosperms of the <em>Jurassic</em>.
<em>Varied dispersal mechanisms in angiosperms co-evolved with the evolution of certain types of fauna. Plants used animal life, including herbivorous reptiles and early mammal-like species to disperse large seeds.</em>