Answer:
<em><u>D. The first flowering plants were introduced toward the end of the Mesozoic era.</u></em>
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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>
Each organism is unique because of genetic variation. Each set of genes we inherit from our parents codes for a specific trait. And our DNA is a blueprint for these traits. Not everybody contains the same genes and that is why we are all so beautifully unique.
A community refers to the total number of populations that inhabit a
specific location or area. This is part of the levels of organization of life. Arranged from the least complex to most
complex it falls 8th in the category. Below are the organization of life:<span>
a. Organelles - the basic part of a living
organism. It refers to the different structures of the cell, whether
prokaryotic or eukaryotic. (Ex. Mitochondria, nucleus)
b. Cells - building blocks of life that are
composed of different molecules responsible for the function of an organism.
(Example: prokaryotic, eukaryotic cells)
c. Tissues - combinations of cells that carry
out a specific function in an organism. (Example: Human skin)
d. Organs - collections of tissues that perform
specific functions. (Ex. heart, lungs)
e. Organ Systems - composed of interconnected
organs that function as a whole. Many organisms, particularly mamamals, are
composed of organ systems. (Ex. respiratory, circulatory systems)
f. Organisms – individual entities that
specifically make-up a population. (Ex. Each tree in the forest is an organism,
each animal in sea is an organism)</span>
g. Population – species living within a specific location. It could be
the same or different species that inhabit a place. (Ex. Birds are species in
the forest as well as bears)
h. Community – refers to the total number of populations that inhabit a
specific location. (Ex. All of the trees, insects, birds that inhabit the
forest are a community)
i. Ecosystem – consists of all living things that function together as a
group which also includes the non-living parts of the environment. (Ex. Rain
water, nitrogen in the soil)
<span>j. Biosphere – the highest organization of life that consist of all the
collection of ecosystems in the planet. It includes the land, air, water, even
the atmosphere of the planet. </span>
