Botanica exam V

1. What are the requirements for seed germination?

• a. Temperature

• b. Water

• c. Oxygen

2. Are all genes expressed in every plant cell?

• No.
  Explanation: Cells specialize by expressing only the genes needed for their function.

3. Why is Virchow’s generalization related to Darwin’s theory of evolution?

• Because Darwin's theory depends on inheritance, and Virchow's idea ("all cells come from pre-existing cells") explains how traits pass from generation to generation.

4. Comparing Parenchyma (P) and Sclerenchyma (S):

• a. Chemical difference: Sclerenchyma cells have lignin in their walls; Parenchyma does not.

• b. Why is Parenchyma considered ancestral to Sclerenchyma?: Parenchyma is simpler and undifferentiated, so it evolved earlier.

5. The endosymbiotic theory states:

• a. Eukaryotic cells originated from prokaryotic cells engulfing other prokaryotic cells.

• b. Evidence: Mitochondria and chloroplasts have their own DNA and reproduce independently.

6. Describe an experiment for: "Auxin (IAA) causes cells to elongate in the dark."

• Materials: Corn seeds, agar blocks, IAA, petri dishes, water, laboratory tools, razor blades.

• Control: No IAA.

• Experimental: With IAA applied.

• Variable: Presence of IAA.

7. Name five plant hormones:

• Ethylene

• Gibberellins

• ABA (Abscisic Acid)

• Cytokinin

• Auxin

8. What is a seed?

• A plant embryo packaged with a food supply inside a protective coat.

9. What is a fruit?

• A mature ovary that protects and helps disperse seeds.

  1. Table of beneficial and negative aspects of Eubacteria:

• Benefits:
  a. Nitrogen fixation for plants.
  b. Production of antibiotics (e.g., streptomycin).

• Negatives:
  a. Cause diseases (e.g., tuberculosis).
  b. Food spoilage.

2. Exchange of genetic material for bacteria:

• a. Transformation: Uptake of free DNA from the environment.

• b. Transduction: DNA transfer via a virus (bacteriophage).

• c. Conjugation: Direct transfer of DNA between bacteria through a pilus.

Are spores a form of reproduction?

• Yes.
  Explanation: They allow organisms to reproduce and survive in harsh conditions.

3. What is the function of a heterocyst for cyanobacteria?

• To fix atmospheric nitrogen into a usable form for the cell.

4. Why should a virus be considered a living organism?

• Because it can reproduce and evolve, even though it needs a host cell.

5. What is the function (purpose) of the streak plate method?

• To isolate a pure colony of bacteria from a mixture.

6. Geological record:

• a. Cyanobacteria changed Earth's rocks by producing oxygen, forming stromatolites.

• b. The oxygen they produced enabled the evolution of aerobic (oxygen-using) organisms.

7. Fungi body structure:
(Skipping drawings as you asked.)

8. Gamete types drawings:
(Skipping drawings as you asked.)

9. Two reasons for recognizing a separate Kingdom for Fungi:

• a. First: Fungi have cell walls made of chitin, not cellulose like plants.

• b. Second: Fungi obtain nutrients by absorption, not photosynthesis.
  
  

Unit II

1. What are two reasons that clay particles are essential for soils? (1)

• a. Small particles increase surface area.

• b. Retain more water and nutrients.

2. Why are anions easily lost from soils and not cations? (1)

• Because anions are repelled by the negatively charged soil particles and easily leach away with water, unlike cations which are attracted.

3. What is totipotency? (1)

• The potential of a single cell to develop into an entire organism.

4. Definition of hydroponics and what botanists learn from it: (1)

• Hydroponics: Growing plants without soil, using nutrient-rich water solutions.

• Botanists learn about plant nutrition, growth requirements, and effects of specific nutrients.

5. Carnivorous plants capture insects for what purpose? (1)

• For nutrient absorption, especially nitrogen and phosphorus.

6. In the absence of transpiration, roots can generate positive pressure. Root pressure results from four steps: (2)

• a. Ions are actively secreted into the xylem.

• b. Water follows the ions osmotically, creating pressure.

7. (Drawing skipped as you requested.)
(You would need to label: Pericycle, Cortex, Plasmodesmata, Xylem Parenchyma, Endodermis, Epidermis, and Phloem.)

8. What are two reasons tropical rainforest soils (e.g., Guavate, El Yunque, Cayey) are bad for agriculture? (2)

• a. Heavy rainfall leaches nutrients from the soil.

• b. Soils are highly weathered and low in essential minerals.

Unit III

1. What are two differences between red and blue light (not color)?

• Blue light has higher energy than red light.

• Red light has a longer wavelength than blue light.

2. One type of Photosynthesis is called C3. Explain why C3: (1)

• Because the first stable product formed during carbon fixation is a 3-carbon molecule (3-phosphoglyceric acid or 3-PGA).

3. What is thigmonastic movement? (1)

• A rapid plant movement in response to touch (e.g., Venus flytrap closing).

4. (Drawing skipped.)
(You would need to draw 3-Phosphoglyceric Acid and Ribulose Diphosphate showing C, H, and O atoms.)

5. Why is there more photosynthesis in the palisade layer than in the spongy layer?

• The palisade layer has more chloroplasts per cell.

• Cells are more tightly packed to maximize light absorption.

6. Photosynthesis evolved 3 billion years ago:

• a. Evidence linking photosynthesis to glycolysis: Both use electron carriers and ATP, suggesting a common origin.

• b. Evidence it evolved in an anaerobic environment: Early photosynthetic organisms did not produce oxygen (anoxygenic photosynthesis), consistent with the low oxygen levels in Earth's early atmosphere.

Vascular tissue differences table:

Unit IV

2. Write a general equation for photosynthesis (names and formulas):

• Equation:
  Carbon dioxide (CO₂) + Water (H₂O) → Glucose (C₆H₁₂O₆) + Oxygen (O₂)

3. What are some advantages of secondary growth?

• a. Provides structural support (thicker stems/trunks).

• b. Increases water and nutrient transport capacity.

4. The process transporting water and minerals to photosynthetic tissues:

• Name: Transpiration-cohesion-tension mechanism

• Geological Era it evolved: Paleozoic Era (specifically, Silurian period)

5. Transporting food (sucrose) from photosynthetic tissue to storage regions:

• Name of process: Translocation

• Major energy source: ATP

6. Name of the theory explaining food transport:

• Pressure-flow hypothesis

7. In xylem cells, is the liquid under positive or negative pressure?

• Negative pressure

8. In phloem cells, is the liquid under positive or negative pressure?

• Positive pressure

9. Sequence of tissues starting from the apical meristem producing secondary tissues:

• Apical meristem → Procambium → Vascular cambium → Secondary phloem → Secondary xylem → Phellogen (cork cambium) → Phellem (cork)

10. Six plant organs:

• Roots

• Stem

• Leaf

• Seed

• Flower

• Fruit

11. Dichotomous key for the six plant organs:
(Example)

1. a. Organ absorbs water — go to 2

2. b. Organ produces food or reproductive structures — go to 3

3. a. Underground — Root

4. b. Above ground — Stem

5. a. Green, flat — Leaf

6. b. Not green, involved in reproduction — go to 4

7. a. Contains seeds — Fruit

8. b. Produces seeds — Flower

9. a. Dormant plant embryo — Seed

Permian and Seed Plants Questions

1. Describe the climate in the Permian that would benefit Coniferophyta: (1)

• The Permian climate was dry and seasonal, which favored the evolution of seed plants like Coniferophyta because they are adapted to survive with less water compared to ferns and mosses.

2. Why are plants like Psilotum, Lycopodium, Equisetum, Polypodium, and most ferns more widely distributed than seed plants? (0.5)

• Because they produce many lightweight spores that are easily dispersed by wind over long distances.

3. The opening into the ovule is called the: (0.5)

• Micropyle

4. The testa (seed coat) originates from the: (0.5)

• Integument of the ovule

Photomicrography Section

5. Name the four types of Microtechniques and how to recognize them: (4)

26. Name the six types of Microscopy and how to recognize them: (6)