Final Exam

Question 1

Why are plants poisonous or otherwise harmful?

Answer 1

• To avoid predators (herbivores)
• Developed weapons like thorns and hairs
• Lethal chemical arsenal (secondary metabolites)

Plants are intentionally trying to hurt herbivores while remaining rooted.

Question 2

Why don’t poisonous plants kill themselves?

Answer 2

• Poisonous chemicals are stored in the vacuole
• The vacuole is a large water-filled sac

As long as the chemicals are tucked away in the vacuole, the remainder of the cell is safe.

Question 3

What is allelopathy?

Answer 3

• Chemical warfare between plants
• Example: Juglone from walnut trees inhibits growth of other plants

Good gardeners avoid planting walnut trees near their gardens.

Question 4

List some reasons why people accidentally ingest poisonous plants.

Answer 4

• Didn’t confirm plant identity
• Mistakenly identified edible plants
• Relied on erroneous folktales
• Ate the wrong part of an edible plant
• Ate during the wrong season
• Poisonous to some but not others
• Didn’t know better (especially children)
• Ate too much of an edible plant

Many people are poisoned by plants due to these misunderstandings.

Question 5

Name a plant that contains alkaloids and is toxic.

Answer 5

Henbane/Mandrake (Mandragora officinale)

Used in witches brews and contains rather toxic alkaloids.

Question 6

What is Jimson Weed and its significance?

Answer 6

• Deadly toxic
• Hallucinogenic in low doses
• Named after Jamestown

Some British sailors died from ingesting it.

Question 7

What is Strychnine used for?

Answer 7

• Nerve toxin
• Previously used medicinally
• Now primarily a rodent poison

Strychnine is highly toxic and not used much anymore.

Question 8

What is the active ingredient in Milkweed that makes it toxic?

Answer 8

Cardiac glycosides (steroids)

Milkweed can be eaten by monarch larvae, making them toxic to birds.

Question 9

What is the Rosary Pea known for?

Answer 9

• Made necklaces
• Children ate it; now illegal

Rosary Pea (Abrus precatorius) is part of the Fabaceae family.

Question 10

True or false: Lily of the Valley is extremely poisonous.

Answer 10

TRUE

All parts of the Lily of the Valley (Convallaria majalis) are toxic.

Question 11

What is the mechanism of injury caused by Cactus thorns?

Answer 11

• Thorns are harmful
• Tiny hairs (glochids) are worse

Glochids can cause severe irritation.

Question 12

What are pyrethrins and their source?

Answer 12

• Nerve toxin to insects
• Found in Chrysanthemum sp.

Extracted from dried flowers, used as an insecticide.

Question 13

What causes hay-fever?

Answer 13

• Wind pollinated species
• Examples: Ragweed, pines, oaks, grasses

Mast cells release histamine upon exposure to allergens.

Question 14

What is urushiol and its effect?

Answer 14

• Produced by poison ivy
• Causes contact dermatitis

Urushiol triggers allergic reactions upon contact.

Question 15

What are the characteristics of algae?

Answer 15

• Diverse group of photosynthetic organisms
• Occur in fresh water, oceans, and moist terrestrial environments
• Base of the food chain
• Range from unicells to huge multicellular organisms
• Lack extensive tissue differentiation
• Do not retain an embryo after sexual reproduction

Algae differ from plants in several key features.

Question 16

How many species of algae are known?

Answer 16

Approximately 28,500

Algae are classified into 10 divisions within two kingdoms: Eubacteria and Protista.

Question 17

Name the major groups of algae.

Answer 17

• Cyanobacteria
• Dinoflagellates
• Diatoms
• Euglenoids
• Green Algae
• Red Algae
• Brown Algae

These groups represent the diversity of algae.

Question 18

What are cyanobacteria also known as?

Answer 18

Blue-green algae

Cyanobacteria are the only group of algae with prokaryotic cells and can carry out nitrogen fixation.

Question 19

Which algae are typically unicellular organisms?

Answer 19

• Diatoms
• Dinoflagellates

They play a vital role in marine and freshwater food chains.

Question 20

Which algae group is most closely related to land plants?

Answer 20

Green Algae

Green algae exhibit the greatest diversity of form.

Question 21

What are red and brown algae commonly known as?

Answer 21

Seaweeds

They include large multicellular marine organisms with complex life cycles.

Question 22

What is Spirulina known for?

Answer 22

Rich source of protein, vitamins, and minerals

It is consumed in the United States.

Question 23

Which brown algae is used in soup, salads, and noodles?

Answer 23

Undaria

This is an example of seaweed used directly as food.

Question 24

What are Dulse and Nori used for?

Answer 24

Confection, relish, or in soup and salads

These are products derived from red seaweeds.

Question 25

What are some **industrial applications** of seaweeds?

Answer 25

* Alginic acid * Carrageenan * Agar ## Footnote Carrageenan is commonly found in ice cream, pudding, toothpaste, and lotions.

Question 26

What are **algal blooms**?

Answer 26

Sudden population explosions of certain algal species ## Footnote They can lead to environmental damage.

Question 27

What happens after an **algal bloom**?

Answer 27

* Nutrients and oxygen levels drop * Algae and other organisms begin to die * The whole ecosystem may die ## Footnote Algal blooms are especially hazardous when producing toxins.

Question 28

What are **Red Tides**?

Answer 28

Blooms of dinoflagellates ## Footnote Dinoflagellates are known toxin producers.

Question 29

What are the **characteristics of fungi**?

Answer 29

* Diverse organisms (yeasts, molds, mushrooms) * Composed of mycelium and hyphae * Reproduce by spores (sexual or asexual) * Absorptive nutrition through enzyme secretion * Chitin in cell walls as a distinguishing feature * Classification based on sexual reproduction methods * Many are asexual fungi ## Footnote Fungi play various roles in the environment, including decomposition and forming symbiotic relationships.

Question 30

What role do fungi play in the **environment**?

Answer 30

* Saprobes recycling nutrients * Mycorrhizal fungi in symbiotic relationships * Pathogens causing plant diseases * Major impact on crops (e.g., rust and smut fungi) * Sudden oak death affecting California forests ## Footnote Fungi are crucial for nutrient cycling and can have devastating effects on agriculture and ecosystems.

Question 31

What is the process of **wine making**?

Answer 31

* Begins with wine grapes (Vitis vinifera) * Types: red or white grapes * White wine: crushed, pressed, fermented * Red wine: crushed, fermented, pressed * Aged in oak barrels, then bottled ## Footnote The fermentation of sugar to alcohol by yeast is essential for wine production.

Question 32

What is the difference between **table wines** and **fortified wines**?

Answer 32

* Table wines: 9% to 14% alcohol * Fortified wines: 15% to 21% alcohol (brandy added) ## Footnote Fortified wines have a higher alcohol concentration due to the addition of brandy.

Question 33

What is the average **alcoholic content** of beer?

Answer 33

4% to 6% ## Footnote Beer is produced from fermented grains, starting with starch preparation.

Question 34

How are **distilled spirits** produced?

Answer 34

* Beer or wine is boiled * Alcoholic vapors are collected and condensed * Alcohol concentration raised to 40% to 50% ## Footnote Distilled spirits include brandy, whiskey, gin, and vodka.

Question 35

What are the effects of **moderate alcohol consumption**?

Answer 35

* Reduces coronary heart disease risk * Raises HDL levels * Inhibits blood clots ## Footnote However, drinking alcohol during pregnancy is not recommended due to fetal alcohol syndrome risks.

Question 36

What is **Quorn mycoprotein**?

Answer 36

High quality protein food from the mycelium of Fusarium venenatum ## Footnote It has a meat-like texture and is used for various meat substitutes.

Question 37

True or false: Many fungi are **edible** and can be cultivated to avoid poisoning.

Answer 37

TRUE ## Footnote Cultivating edible mushrooms reduces the risk of mistaking poisonous varieties for safe ones.

Question 38

What is the role of fungi in **food modification**?

Answer 38

* Enhance nutritional value * Improve flavor and appearance through fermentation ## Footnote Fungi release enzymes during fermentation that modify foods.