Botanica exam V

UPR Cayey

Requirements for seed germination

Temperature, Water, Oxygen.

Gene expression in plant cells

Not all genes are expressed in every plant cell; cells specialize by expressing only the necessary genes.

Virchow's generalization connection to Darwin's theory

Virchow's idea that all cells come from pre-existing cells explains how traits pass from generation to generation.

Difference between Parenchyma and Sclerenchyma

Sclerenchyma cells have lignin; Parenchyma does not.

Endosymbiotic theory

Eukaryotic cells originated from prokaryotic cells engulfing other prokaryotic cells; evidence includes mitochondria and chloroplasts having their own DNA.

Experiment design for Auxin (IAA) effect

• Independent: Auxin concentration

• Dependent: Amount of bending/growth

• Control group: No auxin

• Control variables: Same plant, same light, same water, same time

Plant hormones

Ethylene, Gibberellins, ABA (Abscisic Acid), Cytokinin, Auxin(IAA).

Definition of a seed

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

Definition of a fruit

A mature ovary that protects and helps disperse seeds.

Benefits of Eubacteria

Nitrogen fixation and production of antibiotics.

Negatives of Eubacteria

Cause diseases and food spoilage.

Bacterial exchange of genetic material: Transformation

Uptake of free DNA from the environment.

Bacterial exchange of genetic material: Transduction

DNA transfer via a virus (bacteriophage).

Bacterial exchange of genetic material: Conjugation

Direct transfer of DNA between bacteria through a pilus.

Function of heterocyst in cyanobacteria

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

Why virus is considered living

It can reproduce and evolve, needs a host cell.

Function of streak plate method

To isolate a pure colony of bacteria from a mixture.

Cyanobacteria's impact on Earth

They produced oxygen, forming stromatolites and enabling evolution of aerobic organisms.

Reasons for recognizing Fungi as a separate kingdom

Fungi have chitin in cell walls; they obtain nutrients by absorption.

Reasons clay particles are essential for soils

Increase surface area and retain more water and nutrients.

Why are anions easily lost from soils

Because anions are repelled by negatively charged soil particles and leach away.

Definition of totipotency

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

Definition of hydroponics

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

Purpose of carnivorous plants capturing insects

For nutrient absorption, especially nitrogen and phosphorus.

Root pressure process

• Active transport of ions into the xylem.

• Decrease in water potential inside the xylem (because of the ion buildup).

• Water enters xylem by osmosis from surrounding root cells.

• Positive pressure builds up in the xylem, pushing water upward.

Two reasons tropical rainforest soils are bad for agriculture

Heavy rainfall leaches nutrients; soils are highly weathered and low in minerals.

Differences between red and blue light

Blue light has higher energy; red light has a longer wavelength.

What is C3 photosynthesis

C3 refers to the first stable product of carbon fixation being a 3-carbon molecule.

What is thigmonastic movement

A rapid plant movement in response to touch.

Why is photosynthesis more in the palisade layer

More chloroplasts per cell, tightly packed to maximize light absorption.

Evidence linking photosynthesis to glycolysis

Both use electron carriers and ATP suggesting a common origin.

Vascular tissue differences: Xylem

Cell types are tracheids and vessel elements, dead at maturity.

Vascular tissue differences: Phloem

Cell types are sieve tube elements and companion cells, living at maturity.

General equation for photosynthesis

CO₂ + H₂O → C₆H₁₂O₆ + O₂.

Advantages of secondary growth

Provides structural support and increases water/nutrient transport capacity.

Name and geological era for CAT (what does it stand for)

cohesion-adhesion-transpiration; evolved in Paleozoic Era.

Process of food transport to storage regions

Translocation; major energy source is ATP.

Theory explaining food transport in plants

Pressure-flow hypothesis.

Liquid pressure in xylem cells

Negative pressure.

Liquid pressure in phloem cells

Positive pressure.

Sequence of tissues producing secondary tissues

Apical meristem → Procambium → underefitated cambrium (primary sylem and phloem) → Vascular cambium → Secondary phloem → Secondary xylem

Six plant organs

Roots, Stem, Leaf, Seed, Flower, Fruit.

Micropyle

The opening into the ovule.

Origin of seed coat (testa)

From the integument of the ovule.

Four types of Microtechniques

Whole mount, Cross section, Longitudinal section, Squashed.

Six types of Microscopy

Light microscopy, dark microscopy, Fluorescence microscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Confocal microscopy, phase constart