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Unit 1 Spores and Seeds
Reading Comprehension
There are several ways to categorize the many types of plants on Earth, but when it
comes to reproduction, plants can generally be divided into two basic categories: those
which reproduce by means of seeds, and those which reproduce through the use of
spores. Though they serve the same basic functions, the differences between these
two reproductive units and the methods of reproduction they represent are many.
The more familiar of the two categories is the seed-bearing plant. Seeds are basically
small, enclosed units that contain an embryo of the parent plant. The embryo, an
undeveloped version of the parent plant, is the most important component, as it will
eventually grow into a new plant. All seeds feature certain protective structures to ensure
the health of the embryo. For instance, it is usually protected by an outer covering
known as a seed coat, a layer of material that helps both to retain moisture in the seed
and to keep it from becoming damaged by environmental factors. Seeds also contain a
source of food for the embryo to feed on as it develops. This food is usually a
combination of oils, starches, and proteins, and occupies the space between the embryo
and the seed coat.
Seeds are considered the end stage in the process of reproduction in seed plants,
having been preceded by other familiar processes such as pollination and flowering. All
that remains is for the seeds to be spread, which may be accomplished with the help of
wind, water, or even animals. Seed plants are the most advanced form of plant in
evolutionary terms. For this reason, they often dominate their respective ecological
niches, like forests and grasslands. Those few plants that still reproduce entirely
asexually — without a partner — represent the most basic form. Between them lies an
intermediate stage in the evolution of plants, the spore plant.
Spores are much simpler in their make-up than seeds, and are a common
reproductive unit of bacteria and fungi in addition to plants. One of the key differences
between seeds and spores is that spores do not have the same support mechanisms,
such as stored food resources or defensive coverings. So, spores from plants are less
able to survive in unfavorable conditions for long periods of time before growing into a
full plant. As a rule, spores are released in large numbers as a way of giving more of
them a better chance of growing to maturity.
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Reading Comprehension
There are several ways to categorize the many types of plants on Earth, but when it
comes to reproduction, plants can generally be divided into two basic categories: those
which reproduce by means of seeds, and those which reproduce through the use of
spores. Though they serve the same basic functions, the differences between these
two reproductive units and the methods of reproduction they represent are many.
The more familiar of the two categories is the seed-bearing plant. Seeds are basically
small, enclosed units that contain an embryo of the parent plant. The embryo, an
undeveloped version of the parent plant, is the most important component, as it will
eventually grow into a new plant. All seeds feature certain protective structures to ensure
the health of the embryo. For instance, it is usually protected by an outer covering
known as a seed coat, a layer of material that helps both to retain moisture in the seed
and to keep it from becoming damaged by environmental factors. Seeds also contain a
source of food for the embryo to feed on as it develops. This food is usually a
combination of oils, starches, and proteins, and occupies the space between the embryo
and the seed coat.
Seeds are considered the end stage in the process of reproduction in seed plants,
having been preceded by other familiar processes such as pollination and flowering. All
that remains is for the seeds to be spread, which may be accomplished with the help of
wind, water, or even animals. Seed plants are the most advanced form of plant in
evolutionary terms. For this reason, they often dominate their respective ecological
niches, like forests and grasslands. Those few plants that still reproduce entirely
asexually — without a partner — represent the most basic form. Between them lies an
intermediate stage in the evolution of plants, the spore plant.
Spores are much simpler in their make-up than seeds, and are a common
reproductive unit of bacteria and fungi in addition to plants. One of the key differences
between seeds and spores is that spores do not have the same support mechanisms,
such as stored food resources or defensive coverings. So, spores from plants are less
able to survive in unfavorable conditions for long periods of time before growing into a
full plant. As a rule, spores are released in large numbers as a way of giving more of
them a better chance of growing to maturity.
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