written possible questions botany practical exam 1 final

Why do you start with the lowest microscope magnification?

To locate the specimen easily and focus safely.

How do you calculate total magnification?

Eyepiece magnification × objective magnification.

What happens to the field of view when magnification increases?

The field of view becomes smaller.

What does Benedict's solution test for, and what indicates a positive result?

Simple sugars; blue to orange, after heating.

What does Biuret solution test for, and what indicates a positive result?

Proteins; purple or violet color.

What does iodine test for, and what indicates a positive result?

Starch; blue-black color.

What is the purpose of a positive control?

To confirm that the test works.

What is the purpose of a negative control?

To show what a negative result looks like.

What is the purpose of paper chromatography?

To separate different plant pigments.

Why do pigments travel different distances during chromatography?

Because they differ in solubility and attraction to the paper.

How do you calculate the Rf value?

Distance traveled by pigment ÷ distance traveled by solvent.

Why do most leaves appear green?

Chlorophyll reflects more green light than red or blue light.

What is the purpose of mitosis?

Growth, repair, and production of genetically identical cells.

What is the difference between mitosis and meiosis?

Mitosis produces two genetically identical cells; meiosis produces four genetically different haploid cells.

Why are root tips commonly used to observe mitosis?

They contain actively dividing cells.

Where does meiosis occur in a fern?

In the sporangia.

What is the first structure to emerge during seed germination?

The radicle (embryonic root).

Why do seeds need water to germinate?

To activate enzymes and restart growth.

How do you calculate the average seedling length?

Add all seedling lengths and divide by the number of seedlings.

How do you calculate the range of seedling lengths?

Largest measurement − smallest measurement.

What is the difference between parenchyma, collenchyma, and sclerenchyma?

Parenchyma: storage and metabolism. Collenchyma: flexible support. Sclerenchyma: rigid support.

What is the difference between primary and secondary growth?

Primary increases length; secondary increases thickness.

What are the three primary meristems and what do they produce?

Protoderm → epidermis; ground meristem → ground tissue; procambium → primary vascular tissue.

What is the purpose of lignin in plant cell walls?

Provides strength, rigidity, and water resistance.

What are the four main functions of roots?

Anchorage, water absorption, mineral absorption, and storage.

What is the function of the Casparian strip?

Controls movement of water and minerals into the stele.

What happens in the three root growth regions?

Division: new cells form. Elongation: cells lengthen. Maturation: cells differentiate.

What is the difference between a taproot and a fibrous root system?

Taproot: one main root. Fibrous: many similarly sized roots.

How do monocot and dicot stem vascular bundles differ?

Monocot: scattered bundles. Dicot: bundles arranged in a ring.

What is the difference between xylem and phloem?

Xylem transports water and minerals; phloem transports sugars.

What is the function of vascular cambium?

Produces secondary xylem inward and secondary phloem outward.

What is the difference between early wood and late wood?

Early wood: larger cells, thinner walls. Late wood: smaller cells, thicker walls.

What is the difference between heartwood and sapwood?

Heartwood: older, nonconducting xylem. Sapwood: younger, water-conducting xylem.

What is the difference between transverse, radial, and tangential wood sections?

Transverse: across the trunk. Radial: lengthwise through the center. Tangential: lengthwise, parallel to growth rings.

What is the function of cork cambium?

Produces protective periderm tissues, including cork.

What is the main function of root hairs?

Increase surface area to absorb water and minerals.

How does water enter root hairs?

By osmosis.

What is the pathway of water from soil into the root?

Soil → root hair → cortex → xylem.

What bacteria are found in legume root nodules?

Rhizobium (rhizobia).

What is the function of root nodules?

House bacteria that fix atmospheric nitrogen into ammonia.

What type of relationship exists between legumes and Rhizobium?

Mutualism — both benefit.

What is nitrogen fixation?

Conversion of atmospheric nitrogen (N₂) into ammonia (NH₃).

What is nitrification?

Conversion of ammonium into nitrite, then nitrate.

What is denitrification?

Conversion of nitrate into nitrogen gas (N₂), returning it to the atmosphere.

Why is nitrogen important to plants?

Plants need nitrogen to make proteins, nucleic acids, and chlorophyll.

Is chromatography paper polar or nonpolar?

Polar, because it contains cellulose.

Which pigments travel farther in paper chromatography

Less polar pigments because they dissolve better in the solvent and are less attracted to the polar paper.

Which pigments travel the shortest distance in chromatography ?

More polar pigments because they are more attracted to the polar paper.

Which plant pigment is the least polar?

Carotene (orange);

Which is more polar, chlorophyll a or chlorophyll b?

Chlorophyll b is more polar than chlorophyll a.

polar pigment travel ____ and have ___ Rf value

lower, smaller

non-polar pigment travel___ and have ____ Rf value

farther, larger

what is pinnate in a leaf

1 central vein w/ other major veins branching off from it— bird feather

what is palmate in a leaf

Has several major veins branching off from a common point.

simple leaves consists of what

only one leaf blade

compound leaves consist of what

2 or more leaflets in blade

pinnately are arrange ?

leaflets arranged along a central axis

palmately are arrange?

leaflets arise from a common point at end of petiole

in leaves monocot is

Parallel to each other