Genetically Modified Organisms in Agriculture

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Questions and Answers

What characteristic of seedless vascular plants allows them to grow taller than bryophytes?

Vascular tissue (correct)

Moist environments

Dominant sporophytes

Flagellated sperm

What is the primary reason why plants with lignified vascular tissue had an evolutionary advantage?

Increased flagellated sperm production

Ability to grow in moist environments

Access to sunlight and spore dispersal (correct)

Development of well-rooted systems

What type of leaves do all lycophytes have?

Circinate leaves

Megaphylls

Fiddlehead tips

Microphylls (correct)

What is the likely origin of true roots in vascular plants?

Subterranean stems Signup and view all the answers

What is the trend among plants in terms of life cycles?

Increasing dominance of sporophytes Signup and view all the answers

What is the characteristic of ferns that is reminiscent of ancestral cycads?

Circinate vernation Signup and view all the answers

What is the function of the pollen tube in the fertilization process?

To dig through the megasporangium and reach the ovule Signup and view all the answers

What is the significance of the heat from natural wildfires in seed dispersal?

It loosens the structure of the cones to disperse seeds Signup and view all the answers

What characteristic of gymnosperms made them better adapted to arid climates?

Their thick cuticles and needle-like leaves Signup and view all the answers

What is the earliest evidence of seed plants dated to?

360 million years ago Signup and view all the answers

What was the dominant species at the end of the Cretaceous period?

Angiosperms Signup and view all the answers

What type of tree had a woody stem but did not bear seeds?

Archaeopteris Signup and view all the answers

What is the primary advantage of using transgenic organisms in agriculture?

Increasing world food supply without expanding farmlands Signup and view all the answers

What is the function of the Bt toxin in genetically engineered crops?

To produce a toxin that is deadly to insects but harmless to vertebrates Signup and view all the answers

What is the primary concern regarding the use of glyphosate-resistant crops?

They lead to the development of glyphosate-resistant weeds Signup and view all the answers

What is the purpose of genetically engineered 'Golden Rice'?

To address vitamin A deficiencies in poor communities Signup and view all the answers

What is the definition of biomass in the context of biofuels?

The total mass of organic matter in a group of organisms in a particular habitat Signup and view all the answers

What is the potential negative effect of glyphosate on human and livestock health?

It can interfere with beneficial gut bacteria Signup and view all the answers

What is the characteristic feature of the male gametophytes of cycads?

They are elongated cones Signup and view all the answers

Which of the following gymnosperms can thrive in air-polluted environments?

Ginkgophyta Signup and view all the answers

Which gymnosperm phylum is characterized by the presence of vessel elements in some of its species?

Gnetophyta Signup and view all the answers

Which of the following is NOT a characteristic of conifers?

They are deciduous trees Signup and view all the answers

What is the term for the 'fruits' of Ginkgo biloba?

Arils Signup and view all the answers

Which of the following is an example of a living fossil?

Wollemi pine Signup and view all the answers

What is the primary function of fruits in angiosperms?

To protect seeds and aid in their dispersal Signup and view all the answers

What is the estimated time period when angiosperms originated and diversified?

20-30 million years ago Signup and view all the answers

What is the characteristic of the earliest known angiosperm fossil, Archaefructus?

It was a herbaceous and aquatic plant Signup and view all the answers

What is the estimated time of divergence between angiosperms and gymnosperms?

305 million years ago Signup and view all the answers

Which of the following is NOT a characteristic of flowers in angiosperms?

Ability to synthesize nutrients and energy Signup and view all the answers

What is the location where some of the earliest extant angiosperms, such as Amborella trichopoda, can be found?

New Caledonia Signup and view all the answers

Study Notes

Flower and Fruit Adaptations

Flowers are variable in shape, size, color, odor, and symmetry.
Fruits are formed when the ovary wall thickens and matures, protecting seeds and aiding in their dispersal.
Mature fruits can be either fleshy or dry.
Various fruit adaptations help disperse seeds by wind, water, or animals to new locations.

Angiosperm Evolution

Angiosperms originated during the Cretaceous period, around 140 million years ago, and diversified over a 20-30 million year period.
The earliest pollen fossils with angiosperm characteristics are 130 million years old.
The earliest angiosperm fossil, Archaefructus, was herbaceous and aquatic.

Angiosperm Phylogeny

Angiosperms and gymnosperms diverged 305 million years ago.
Amborella trichopoda, water lilies, and star anise are some of the earliest extant angiosperms.

Ferns and Seedless Vascular Plants

Ferns were the first plants to grow tall.
Seedless vascular plants have flagellated sperm and are restricted to moist environments.
They have vascular tissue that allows them to transport water to greater heights, enabling them to grow taller.

Origins and Traits of Vascular Plants

Living vascular plants are characterized by life cycles with dominant sporophytes.
They have transport mechanisms in xylem and phloem.
They have well-developed roots and leaves.
Roots anchor the plant in soil and allow the shoot system to grow taller.

Early Seed Plants and the Rise of Gymnosperms

Characteristics of seed plants are found in the late Devonian period, 380 million years ago.
A fossil of the genus Elkinsia from 360 million years ago provides the earliest evidence of seed plants.
Gymnosperms are better adapted to arid climates due to having thick cuticles and needle-like leaves that reduce surface area.

Angiosperms and Gymnosperms

Angiosperms only began to replace gymnosperms as the dominant species at the end of the Cretaceous period.

Transgenic Organisms and Biotechnology

Transgenic organisms have been engineered to express a gene from another species.
Pros of transgenic organisms include reducing world hunger and malnutrition, and reducing fossil fuel dependency.

Gymnosperm Diversity

Cycadophyta (cycads) have large cones, palm-like leaves, and flagellated sperm.
Ginkgophyta (Ginkgo biloba) has flagellated sperm and a high tolerance to air pollution.
Gnetophyta (three genera: Gnetum, Ephedra, Welwitschia) have some species that are tropical, while others live in deserts.
Coniferophyta (conifers) have woody cones, and most species have needle-like leaves.

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Description

Learn about the pros and cons of transgenic organisms in agriculture, including their potential to increase food supply and reduce pesticide use.