Plant Vascular System

Plant Structure and Function

• Plants have complex features and structures, including vascular tissues (xylem and phloem) that transport dissolved food substances, mineral salts, and water.
• Not all plants have vascular tissues; they are primarily found in higher plants such as ferns, angiosperms, and gymnosperms.
• Vascular tissues are essential for plant functionality, including respiration and translocation.

Onions

• Onions make us cry because they release enzymes that convert amino acid sulfoxides into a sulfenic acid, which reacts with water in our eyes to form sulfuric acid, an irritant.

Asters

• There are over 180 species of aster flowers.
• Asters are perennial plants that come back every year.
• They have lanceolate-shaped leaves that vary in size and color.
• Asters are relatively easy to care for and can thrive in various environments.

Citrus Greening

• Citrus greening, also known as Huanglongbing, is a devastating disease that affects all citrus plants.
• It is spread by tiny insects called psyllids and by grafting pieces of different plants together.
• There is no cure for citrus greening, but researchers are working on developing HLB-resistant citrus plants.

Plant Life Cycle

• All plants have a life cycle that includes a change between two different forms, or stages: the sporophyte (diploid) and the gametophyte (haploid).
• The sporophyte produces haploid spores through meiosis, which grow into gametophytes.
• The gametophyte grows into a mature plant, which produces sporophytes.

Mosses

• Mosses are non-vascular plants that belong to Phylum Bryophyta.
• They do not have flowers, roots, or seeds and are seedless.
• Mosses have a haploid stage and a diploid stage, and they reproduce sexually.

Ferns

• Ferns are a group of seedless, vascular plants that reproduce through spores.
• They undergo two distinct life cycles before becoming a mature fern.
• Ferns have a haploid stage and a diploid stage, and they reproduce sexually.

Angiosperms

• Angiosperms are a group of flowering vascular plants that make up approximately 80% of plant species.
• They have two distinct life stages: the haploid stage and the diploid stage.
• Angiosperms can produce perfect (bisexual) flowers, imperfect (unisexual) flowers, or both.

Tropism

• Tropism is an involuntary response of an organism associated with growth rather than movement.
• There are many forms of tropisms, including gravitropism, phototropism, hydrotropism, thigmotropism, and chemotropism.
• Auxin is a hormone that controls the expression of genes involved in tropism.

Photoperiodicity

• Photoperiodicity is the response of plants to the 24-hour light/dark cycle.
• Plants sense light with photoreceptors and can be influenced by the length of daylight.
• There are three types of plants: short-day, long-day, and day-neutral plants.

Plant Life Cycles

• The growing season is the time frame in which plants can grow.
• There are three types of plant life cycles: annual, biennial, and perennial.
• Annual plants complete their life cycle in one growing season.
• Biennial plants produce leaves and roots in the first growing season and flower and seed in the second.
• Perennial plants can live for multiple growing seasons.

Plant Hormones

• Plant hormones are chemicals that carry messages from one location in the body to another.
• There are five main plant hormone groups: auxins, cytokinins, gibberellins, ethylene, and abscisic acid.
• These hormones are categorized into two groups: plant growth promotion and plant growth inhibition.

Ovary of a Flower

• The ovary of a flower is the location where fertilization and seed development occur.
• The ovary is composed of an ovary wall, locule, placenta, funiculus, and ovule.
• There are five basic ovule placentations: parietal, free central, axile, basal, and marginal.

Flowers

• Flowers are composed of four whorls containing different parts: sepals, petals, stamen, stigma, style, and ovary.
• The ovary of a flower is the location where fertilization and seed development occur.
• Flowers are highly diverse and specialized, and they produce a seed-bearing fruit to continue the species.

Stigma

• The stigma is part of the female reproductive system of a flower.
• It is found in the center of a flower and helps to collect pollen.
• The stigma is waxy or sticky to collect the dry pollen.

Monocots and Dicots

• Angiosperms are further divided into monocotyledons (monocots) and dicotyledons (dicots).
• Monocots are defined as plants that have one cotyledon or seed leaf after germination.
• Dicots have two cotyledons or seed leaves.

Environmental Pollution

• Environmental pollution is anything released into the environment that can cause harm.

• Examples of environmental pollution include air, land, and water pollution.

• Types of pollution include physical, chemical, and biological pollution.### Biological Pollutants

• Biological pollutants are substances that can cause human harm and are derived from the environment.

• An example of a biological pollutant is pollen, which can cause allergies in humans.

• Biological pollutants can adapt to their surroundings due to their biological origins.

Air Pollution

• Air pollution is the presence of materials or forms of energy in the atmosphere that can pose a risk, damage, or nuisance to living beings.
• Air pollutants can come from natural or human sources, and can be single (point) or multiple (non-point) sources.
• Air pollutants can be primary (causing direct damage) or secondary (formed from reactions with other atmospheric components).

Clean Air Act and EPA

• The US Congress established the Clean Air Act of 1970 to detect, decrease, and regulate air pollution.
• The Clean Air Act created the EPA, which monitors and enforces air pollution regulations.
• The EPA identifies and establishes limits for six hazardous air pollutants: carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), particulate matter (PM), and lead.
• The EPA also established the Air Quality Index (AQI) to inform the public about current air quality.

Global Warming

• Global warming refers to the earth's atmospheric temperature warming due to natural or manmade causes, resulting in changes to weather patterns.
• The greenhouse effect is the trapping of heat by gases in the atmosphere, which is enhanced by an increase in greenhouse gases.
• Greenhouse gases, such as carbon dioxide, methane, nitrous oxide, and water vapor, hold extra heat near the earth's surface.
• The concentration of carbon dioxide is increasing, leading to a warming trend in the earth's average temperature.
• The increase in greenhouse gases may have natural and/or manmade causes, including volcanoes, livestock, and fossil fuel combustion.

Plant Structure and Function

• Plants have complex features and structures, including vascular tissues (xylem and phloem) that transport dissolved food substances, mineral salts, and water.
• Not all plants have vascular tissues; they are primarily found in higher plants such as ferns, angiosperms, and gymnosperms.
• Vascular tissues are essential for plant functionality, including respiration and translocation.

Onions

• Onions make us cry because they release enzymes that convert amino acid sulfoxides into a sulfenic acid, which reacts with water in our eyes to form sulfuric acid, an irritant.

Asters

• There are over 180 species of aster flowers.
• Asters are perennial plants that come back every year.
• They have lanceolate-shaped leaves that vary in size and color.
• Asters are relatively easy to care for and can thrive in various environments.

Citrus Greening

• Citrus greening, also known as Huanglongbing, is a devastating disease that affects all citrus plants.
• It is spread by tiny insects called psyllids and by grafting pieces of different plants together.
• There is no cure for citrus greening, but researchers are working on developing HLB-resistant citrus plants.

Plant Life Cycle

• All plants have a life cycle that includes a change between two different forms, or stages: the sporophyte (diploid) and the gametophyte (haploid).
• The sporophyte produces haploid spores through meiosis, which grow into gametophytes.
• The gametophyte grows into a mature plant, which produces sporophytes.

Mosses

• Mosses are non-vascular plants that belong to Phylum Bryophyta.
• They do not have flowers, roots, or seeds and are seedless.
• Mosses have a haploid stage and a diploid stage, and they reproduce sexually.

Ferns

• Ferns are a group of seedless, vascular plants that reproduce through spores.
• They undergo two distinct life cycles before becoming a mature fern.
• Ferns have a haploid stage and a diploid stage, and they reproduce sexually.

Angiosperms

• Angiosperms are a group of flowering vascular plants that make up approximately 80% of plant species.
• They have two distinct life stages: the haploid stage and the diploid stage.
• Angiosperms can produce perfect (bisexual) flowers, imperfect (unisexual) flowers, or both.

Tropism

• Tropism is an involuntary response of an organism associated with growth rather than movement.
• There are many forms of tropisms, including gravitropism, phototropism, hydrotropism, thigmotropism, and chemotropism.
• Auxin is a hormone that controls the expression of genes involved in tropism.

Photoperiodicity

• Photoperiodicity is the response of plants to the 24-hour light/dark cycle.
• Plants sense light with photoreceptors and can be influenced by the length of daylight.
• There are three types of plants: short-day, long-day, and day-neutral plants.

Plant Life Cycles

• The growing season is the time frame in which plants can grow.
• There are three types of plant life cycles: annual, biennial, and perennial.
• Annual plants complete their life cycle in one growing season.
• Biennial plants produce leaves and roots in the first growing season and flower and seed in the second.
• Perennial plants can live for multiple growing seasons.

Plant Hormones

• Plant hormones are chemicals that carry messages from one location in the body to another.
• There are five main plant hormone groups: auxins, cytokinins, gibberellins, ethylene, and abscisic acid.
• These hormones are categorized into two groups: plant growth promotion and plant growth inhibition.

Ovary of a Flower

• The ovary of a flower is the location where fertilization and seed development occur.
• The ovary is composed of an ovary wall, locule, placenta, funiculus, and ovule.
• There are five basic ovule placentations: parietal, free central, axile, basal, and marginal.

Flowers

• Flowers are composed of four whorls containing different parts: sepals, petals, stamen, stigma, style, and ovary.
• The ovary of a flower is the location where fertilization and seed development occur.
• Flowers are highly diverse and specialized, and they produce a seed-bearing fruit to continue the species.

Stigma

• The stigma is part of the female reproductive system of a flower.
• It is found in the center of a flower and helps to collect pollen.
• The stigma is waxy or sticky to collect the dry pollen.

Monocots and Dicots

• Angiosperms are further divided into monocotyledons (monocots) and dicotyledons (dicots).
• Monocots are defined as plants that have one cotyledon or seed leaf after germination.
• Dicots have two cotyledons or seed leaves.

Environmental Pollution

• Environmental pollution is anything released into the environment that can cause harm.

• Examples of environmental pollution include air, land, and water pollution.

• Types of pollution include physical, chemical, and biological pollution.### Biological Pollutants

• Biological pollutants are substances that can cause human harm and are derived from the environment.

• An example of a biological pollutant is pollen, which can cause allergies in humans.

• Biological pollutants can adapt to their surroundings due to their biological origins.

Air Pollution

• Air pollution is the presence of materials or forms of energy in the atmosphere that can pose a risk, damage, or nuisance to living beings.
• Air pollutants can come from natural or human sources, and can be single (point) or multiple (non-point) sources.
• Air pollutants can be primary (causing direct damage) or secondary (formed from reactions with other atmospheric components).

Clean Air Act and EPA

• The US Congress established the Clean Air Act of 1970 to detect, decrease, and regulate air pollution.
• The Clean Air Act created the EPA, which monitors and enforces air pollution regulations.
• The EPA identifies and establishes limits for six hazardous air pollutants: carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), particulate matter (PM), and lead.
• The EPA also established the Air Quality Index (AQI) to inform the public about current air quality.

Global Warming

• Global warming refers to the earth's atmospheric temperature warming due to natural or manmade causes, resulting in changes to weather patterns.
• The greenhouse effect is the trapping of heat by gases in the atmosphere, which is enhanced by an increase in greenhouse gases.
• Greenhouse gases, such as carbon dioxide, methane, nitrous oxide, and water vapor, hold extra heat near the earth's surface.
• The concentration of carbon dioxide is increasing, leading to a warming trend in the earth's average temperature.
• The increase in greenhouse gases may have natural and/or manmade causes, including volcanoes, livestock, and fossil fuel combustion.