26.4 The Role of Seed Plants

By the end of this section, you will be able to explain how angiosperm diversity is due to multiple complex interactions with animals.

Plants play a key role in the stabilization of soils, cycling of carbon, and climate moderation.
Seed plants provide shelter to many life forms, as well as food for herbivores.
The secondary metabolites of the plant are used for various purposes.
Plants are the most important part of animal life.

The evolution of flowering plants and insects is a hypothesis that has received a lot of attention and support.

The driving force of pollination is believed to be herbivory.

In nature,evolution of plant defenses and herbivores is easy to observe.
Most plants can't outrun animals and can't use mimicry to hide from them.
There is an arms race between plants and animals.
Some plant seeds, such as acorn and unripened persimmon, are high in alkaloids and therefore undesirable to some animals.
Other plants are protected by bark and some animals have specialized mouth pieces.
Most animals, except for mammals with thick fur and birds with specialized beaks, are deterred by spine and thorns.

Seed plants have been exploiting herbivory for their own benefit.

The dispersal of fruits by animals is an example of mutualistic relationships.
In return for spreading the plant's genetic material to a wider area, the plant gives the herbivore a source of food.

An extreme example of coevolution between an animal and a plant is exemplified by Mexican acacia trees.

The ants nest in the hollows of large thorns produced by the tree and feed on the sugars produced at the ends of the leaves.
The sugar pellet helps keep the ants out of the hive.
In return, ants discourage herbivores by stinging and attacking leaf-eaters and insects.
The ants help to remove plant pathogens.
The bracken fern (Pteridium aquinilum) is an insect-plant coevolution that is found throughout the world.
There are a number of "adapted plant compounds" in the adult fronds of bane ferns that serve as defensive compounds against non insect attack.
During the "fiddlehead" stage of the plant's development, bracken releases compounds from special "nectaries" that attract ants and even species of jumping spiders, all of which defend the plant's croziers until they are fully unfolded.
These groups of arthropods help reduce the damage that would occur during the early stages of growth.

The flowers pollinated by wind are small and feathery.

Grasses are flowering plants that are wind pollinated.
They produce large amounts of pollen that is carried by the wind.
Oak, maple, and Birches are some of the large trees that are wind pollinated.

Plants have adapted to attract pollinators.

With over 200,000 different plants dependent on animal pollination, the plant needs to advertise to its pollinators with some specificity.
Plants that target animals can be very specific.
It is possible to determine the general type of pollinators favored by a plant by looking at the flower's physical characteristics.
Many bird or insect-pollinated flowers have a liquid in them.
They produce both fertile and sterile pollen for birds and insects.
Many butterflies and bees can detect ultraviolet light, and flowers that attract them usually display a pattern of ultraviolet reflectance that helps them locate the flower's center.
Pollinating insects collect nectar while at the same time are dusted with pollen.
Large, red flowers with little smell and a long funnel shape are preferred by hummingbirds, who have good color perception, a poor sense of smell, and need a strong perch.
White flowers open at night.
Bats, lemurs, and lizards can act as pollinating agents.
Any disruption to these interactions, such as the disappearance of bees, can lead to disaster for agricultural industries that depend heavily on pollinated crops.

When a bee collects a flower's honey, it is dusted by pollen, which it then distributes to other flowers.

The flies like rotting flesh and carrion.

The odor seems to be the main attraction.
The smell of decaying meat is caused by the polyamines putrescine and cadaverine.
Some plants attract flies by producing polyamines similar to those produced by decaying flesh.

The flies look for dead animals because they lay their eggs on them.

A forensic entomologist can determine the time of death by looking at the stages and types of dead animals.

Some flowers are pollinated by bees.

White petunia is a good choice.

While wearing eye protection and gloves, spray one group of flowers with a solution of either putrescine or cadaverine.

The flowers should be placed in a location where flies are present.

Use a table similar to Table 26.2 to record the number of visits to the flowers.

It is possible to record the fly-flower interaction with a video camera.

To get an accurate record of the number of fly visits to the flowers, replay the video in slow motion.

The experiment should be repeated four more times with the same species of flower.

The experiment should be repeated with a different flower that is pollinated by bees.

Compare and contrast the number of visits that flies made to the sprayed flowers with the number of visits that flies made to the un sprayed flowers during the five trials.

For the second flower type used, average the number of visits that flies made to sprayed flowers over the course of the five trials and compare them to the average number of visits that flies made to the un sprayed flowers.

The average number of visits that flies made to the two flower types is compared.

The foundation of human diet is seed plants.

Many societies only eat seed plants for their nutrition.
Rice, wheat, and potatoes dominate the landscape.
During the agricultural revolution, many crops were developed.
The staple of many human diet is cereals.
Fats are derived from crushed seeds, as is the case for peanut and rapeseed oils.
Large quantities of crop plants are consumed by animal husbandry.

Staple crops aren't the only food that comes from seed plants.

Sugar is made from the monocot sugarcane and the eudicot sugar beets.

Coffee beans, tea leaves, and powdered cocoa beans are used to make drinks.

saffron, cloves, black pepper, cinnamon, and the herbs that flavor many dishes come from dried leaves and fruit, such as the red chili pepper.
The scent of perfumes is provided by the volatile oils of flowers and bark.

No discussion of seed plant contribution to human diet would be complete without the mention of alcohol.

Alcoholic beverages are made from plant-derived sugars and starches.

In some cases, the beverages are derived from the fermentation of sugars from fruit, as with wines, and in other cases from the fermentation of sugars from seeds, as with beers.
Sharing of food and beverages contributes to social ritual.

Wood can be used as a source of timber for construction, fuel, and material to build furniture.

The paper is derived from trees.
Woven into cloth are the fibers of seed plants.
Until the advent of synthetic chemical dyes, textile dyes were mostly of plant origin.

It is difficult to quantify the benefits of ornamental seed plants.

These grace private and public spaces, adding beauty and serenity to human lives and inspiring painters and poets alike.

Plants are used for a variety of reasons.

Chocolate is a popular food.

Plants have been used for medicine since ancient times.

There are references to the use of plants in ancient Egyptian, Babylonian, and Chinese writings.
Synthetic therapeutic drugs are derived from plants.
It is important to note that the same plant extract can be a therapeutic remedy at low concentrations, become an addictive drug at higher concentrations, and potentially kill at high concentrations.

The influence of seed plants on human life is large.

Plants are the major source of food and medicine, but they also influence many other aspects of society, from clothing to industry.
The human cultures recognized the benefits of plants early on.
Synthetic chemicals replaced plant-based remedies in the late 19th century.

Drugs derived from natural sources are referred to as pharmacognosy.

With globalization and industrialization, it is possible that knowledge of plants and their uses will be lost to the cultures that fostered them.
This is where ethnobotanists come in.
An ethnobotanist needs to have knowledge of plant life and an appreciation of diverse cultures and traditions to learn about and understand the use of plants in a particular culture.
The Amazon forest is home to an incredible diversity of vegetation and is considered an undiscovered resource of medicine.

A person needs a broad knowledge of plant biology, ecology, and sociology to become an ethnobotanist.

Plants are seen as an important part of human culture by ethnobotanists.

The field of ethnobotany is made up of many disciplines, including biology, anthropology, and ecology.

There is a resource for new food crops and medicines.

Plants provide shelter for many animal species and balance the environment.
There are many threats to plant diversity.
The explosion of the human population, especially in tropical countries where birth rates are highest and economic development is in full swing, is leading to devastating human encroachment into forested areas.
To feed the growing population, humans need arable land so there has been and continues to be massive clearing of trees.
The need for more energy to power larger cities leads to the construction of dams and increased emissions of pollutants.
Poachers log trees for their wood, posing a threat to tropical forests.
There are two tree species on the list that are driven almost to extinction by indiscriminate logging.
Today's unfortunate practice continues due to lack of population control and political will.

At an alarming rate, the number of plant species becoming extinct is increasing.

The extinction of connected animal species can be caused by the disappearance of a single plant.
A real and pressing issue is that many plant species have not been catalogued, and so their place in the system is unknown.
These species are threatened by logging and habitat destruction.
They might become extinct before we have a chance to understand the impact of their disappearance.
Efforts to preserve biodiversity include preserving heirloom seeds and barcoding species.

A lot of crops and ornamental plants are angiosperms.

The structures that protect reproduction from variability in the Carboniferous period were the reason why seed plants appeared 350 million years ago.

The flower and fruit were two of the major innovations.
The flowers were derived.
The embryo is protected from desiccation and from modified leaves by seeds; their color and scent encourages provide it with a store of nutrition to support the early species-specific pollination.
The sporophyte is the main part of a flower.
The reproductive parts of the embryo are protected by the petals and the sepals of the seeds.
The male allows plants to reproduce in the absence of water.
The female gametophytes of seed plants shrank, while the sporophytes gametes, which are within the became prominent structures and the diploid stage became ovary of a carpel.

During the dry wind, water, or animals, the gymnosperms appeared.

The life cycle of the angiosperms is dominated by the sporophyte Triassic.

Double fertilization is unique to the strobilus.
The egg is fertilized by one sperm in the pollen.
There are two ways to form a diploid zygote, the other is by insects who have coevolved two polar nuclei, forming a triploid cell that develops into a flowering plant.
The endosperm is a tissue that protects food storage.
Flowering plants to the embryo are divided into two main groups, the monocots and seed dispersal.
According to the number of cotyledons in the era, angiosperms have become the dominant plant life in seedlings.
Basal angiosperms are older than habitats.

Gymnosperms are Heterosporous seed plants that have multiple interactions naked seeds.

They were with animals.
The development of the dominant plant life has been favored by herbivory.
Plants have defense mechanisms and avoidance of gymnosperms.
Coniferophyta is represented by conifers and can be aided by animals that eat plant fruits.
The angiosperm fruits and seeds have evolved climates and have been carried out by wind.
There are many different ways to capture the wind or attract specific species of Ginkgo biloba.
Gnetophyta is a class of animals.

Plants play an important role in the environment.

They provide raw materials for many industries and are a source of food.
The dominant form of plant life in most of the world is angiosperms.
About 90 percent of the ecosystems are threatened by this.

Plants are seed plants.

The plants have seeds on their leaves.

It's most likely: b.

There are reproductive structures in a flower.

1n, 2n, 2n b. flies.

Plants are a source of food.

There are some cycads that are considered to be extinct.

The trade of insects is very restricted.
Customs officials stopped diversified during the same period.
Is it possible that the plants in question are palm trees, not cycads?

There are pines and cypresses along the sea shore.

The trees grow at sea level because of the cold.
Plants adapted to conifers can funnel large amounts of energy into animal pollination.