|How do animals help plant reproduction?|
|Question Date: 2012-09-25|
Animals can be very important to plant
reproduction in two ways—spreading pollen and
spreading seeds. Pollen contains a plant’s
sperm. Some pollen just blows around in the
wind, but this is very wasteful because a lot of
that pollen will never fall on the female part
of another plant of the same species. Many
plants “pay” animals to deliver their pollen.
They may provide sugar (nectar) to coax animals
into visiting their flowers and pick up pollen.
They only give the animal a little, so the
animal has to go to another flower, where the
pollen can fertilize another plant. Honeybees,
hummingbirds, and some bats do this. Other
plants attract pollinators in different ways.
One plant attracts flies by smelling like dead
animals. Another looks like a female insect and
attracts male insects.
Fruit is another type of payment. An animal
may eat a fruit in one area, by defecate (poop)
in another place, so that seeds get carried to
new areas with the bonus of a dab of fertilizer
and moisture. A large animal may carry a larger
fruit far away to eat it, the drop the seed.
Some animals, like squirrels, collect nuts and
hide them. They don’t find every nut they hide,
so some will sprout in new places.
Relationships where individuals of both species
benefit are called mutualisms.
Most fruit only becomes edible when the seed
inside is mature. Why would this benefit the
Thanks for asking,
Animals help plants by pollinating them, and
be helping to disperse seeds.The droppings of
animals also fertilize plants.
Plants have different reproductive manners.
For instance, flowering plants rely on insects
to harvest pollen. One bee will travel to many
different flowers in one day. When the bee
collects the pollen in the flower from the
stamen, it gets some of the pollen on it's body
and legs; this pollen will be transferred to the
next flower it visits, as the bee must pass by
the pistil. This movement of pollen from one
flower to another allows the plant to reproduce.
Another example are fruit bearing plants -
anything from apples to berries to cucumbers -
essentially any food with a seed inside. When an
animal eats these seeds, they are not processed
in the body, so when they excrete them, the
seeds are then in a new location, and can start
growing. The transport of seeds from one
location to another allows new plants to start
without taking away resources from the original
plant. Conifer trees (pine, spruce, fur, etc.)
use their pinecones - there are seeds in there
that can be eaten or distributed by mice and
other animals. On a whole different note, there
are some carnivorous plants, such as the Venus
fly trap, or the Pitcher plant. These plants
actually eat insects and small animals! It is
important to understand as well that some plants
are dependent on one animal to pollenate it each
year, and if that animal goes extinct or has to
move because of environmental conditions, the
plant will die.
Animals help plant reproduction by helping
spread plant pollen and seeds. For example, bees
pollinate flowers, which is vital to spreading
genes and reproducing. As a point of interest,
insects actually co-evolved with flowering
plants, which means that they evolved together
over time, in a relationship that benefitted
both the plants and the insects, and with a
speed and success that would likely not have
been possible without the relationship. As
another example, many animals eat fruits, and
then travel a long distance before they poop out
the seeds. The travelling animal helps spread
the seeds to far off places, and the manure acts
as a fertilizer to help the seeds grow.
One way animals can help plant reproduction
is by directly fertilizing them. This can be
seen with insects that pollinate flowers. As
they go from plant to plant, pollen grains stick
to them and are deposited into the next flower.
Animals can also help plant reproduction by
dispersing seeds around in different areas.
Seeds can stick to fur or be intentionally
moved, such as when squirrels or birds pick them
up and drop or bury them. Animals that eat seeds
also disperse the seeds when the poop them out.
Some plants have even evolved to where they can
only propagate with the help of animals. A
unique example of this is in the rainforests of
Australia. There is a tree that produces egg-
sized, purple fruit with a pit (seed) in the
center. The seed cannot germinate unless it
passes through the digestive tract of a large,
primitive bird called a Cassowary.
Animals spread seeds around. This is called
seed dispersal. By helping seeds get away from
the parent plant and into new, uncolonized
habitats, they increase not only the seeds'
propensity to survive, but also allow plants to
colonize new areas. In addition, the caching
behavior of many rodents and some birds (caching
seeds to eat them later) plants seeds so that
they have an easier time sprouting.
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