Bio Lab Practical 2

A flowering plant is called a(n)

Question options:

1. gymnosperm

2. angiosperm

3. coniferous

4. bryophyte

angiosperm

On which plant organ will you be labeling the reproductive structures of an angiosperm plant?

Question options:

1. Root

2. Leaf

3. Stem

4. Flower

Flower

Which of the items below best describes the organ systems of a plant?

Question options:

1. Root system and shoot system

2. Monocot and dicot

3. Ground, dermal, and vascular

4. Leaves, stems, and roots

Root system and shoot system

Xylem and phloem are considered what type of plant tissue?

Question options:

Dermal

Ground

Vascular

Vascular

You will observe three distinct regions where cells are developing: zone of division, zone of elongation and zone of differentiation/maturation. What plant organ will you be observing to study these zones?

Question options:

Flower

Stem

Root

Leaves

Root

Label this

a: Terminal bud

b: Flower

c: Blade

d: Fruit

e: Node

f: Stem

g: Petiole

h: Root

I: Root cap

Label this

You come across an unlabeled plant. It has parallel leaf venation, leaves attached vertically to the stem, six flower parts, and a fibrous root system. How many cotyledons would this plant have?

Question options:

one

two

three

four

one

Label the regions

A: Zone of maturation

B: Zone of elongation

C: Zone of cell division 

Xylem is the type of vascular tissue that distributes sugars around the plant.

Question options:

True

False

False

Which type of plant tissue is indicated by the letter A?

Cortex

Vascular

Ground

Dermal

Vascular

Which type of tissue is indicated by "Letter A" in this image? (Ground, vascular, or dermal)

Is this stem from a monocot or a dicot?

Ground

Dicot (Vascular bundles are located near the outer layer.)

What is the name of the dense mesophyll layer of tissue beneath the cuticle at the top portion of the dicot leaf?

Why would you not expect to find this dense layer of tissue in a monocot leaf?

Palisade Mesophyll

In monocot leaves both the upper and lower surfaces are exposed to similar, high levels of sunlight so there is no specialized upper palisade layer and a lower spongy layer, instead it is comprised of uniform, loosely arranged parenchyma cells.

How does the location of stomata differ between monocots and dicots?

Monocot -> Equal distribution of stomata on both the upper and lower epidermis organized in parallel rows
Dicot -> Have a higher concentration of stomata on the lower surface for water conservation

The site of gas exchange in a plant is the ________, these openings are surrounded by ______

which swell with water.

stoma, gaurd cells

Gymnosperms

“naked seeds”

– Seeds do not develop within an ovary

– Coniferous trees

Ex: Pine trees

Angiosperm

“One whose seed is carried in a vessel”
– Seeds develop within an ovary
– Flowering plants

Male flower parts (Anther, Filament)

Anther: Produces pollen

Filament: Supports the anther

Female flower parts (Stigma, Style, Ovary)

Stigma: Holds the pollen grains

Style: Connects the stigma with the ovary

• Supports the stigma so that it can be pollinated

Ovary: Produces ovules which develop into seeds

Monocot

1 cotyledon, paralel (long straight) veins on leaf, scattered vascular bundles in stem, fibrous roots, petals in threes

Dicot

2 cotoledyns, netted veins, vascular bundles in a ring, taproots, petals in 4s or 5s

Dermal tissue

Covers outer surface of herbaceous plants.
• Composed of epidermal cells that secrete the waxy cuticle.
• Waxy cuticle protects against water loss

Ground tissue

Bulk of the primary plant body.
• Composed of parenchyma, collenchyma, and sclerenchyma

Vasular tissue

Transports food, water, hormone, minerals.
• Composed of xylem, phloem, parenchyma, and cambium

Monocot stem

Monocot root

Dicot stem

Dicot root

Primary growth

Occurs at apical meristems
• Increase in length of plants
• Allows roots to push downward through the soil
• Allows shoots to grow upward toward the sun

Secondary growth

Increase in thickness of stems and roots
• Occurs at lateral meristems

Petiole

Leaf stalk or part that connects the leaf to the stem.
• Only seen in dicots!

Blade

The large, flat part of a leaf

Midrib

The large center vein on a leaf

Mesophyll

Palisade –

• Primary site of photosynthesis

• Seen in dicots only

Spongy -

• Contains air & chloroplasts

• Site of photosynthesis and gas exchange

True or False

Apical meristematic tissue is located at the tips of roots & shoots; characterized by amount of cell division occurring in the immediate area

True

During secondary growth, what tissue is responsible for producing new secondary xylem and phloem?

Vascular cambium

Before measuring absorbance, what must be done with the spectrophotometer?

Question options:

Set wavelength to 450 nm

Blank using distilled water

Add KMnO₄ to the blank

Shake the cuvette

Blank using distilled water

Why is a blank used in spectrophotometry?

Question options:

To increase absorbance readings

To measure soil color

To account for absorbance of the solvent and cuvette

To dilute the sample

To account for absorbance of the solvent and cuvette

What is the purpose of creating a standard curve?

Question options:

To measure soil pH

To determine the relationship between absorbance and concentration

To mix solutions evenly

To identify soil color

To determine the relationship between absorbance and concentration

A soil sample has a very light purple color after reacting with KMnO₄. What does this indicate?

Question options:

High KMnO₄ remaining and low active carbon

Low KMnO₄ remaining and high active carbon

High nitrogen levels in the soil

The spectrophotometer was not blanked

Low KMnO₄ remaining and high active carbon

KMnO4 will oxidize active carbon in the soil samples and the KMnO4 will be reduced. In this scenario, KMnO4 is

Question options:

gaining electrons.

losing electrons.

continually losing and gaining electrons.

remaining unchanged.

gaining electrons. 

As KMnO4 is reduced the color of the solution gets darker.

Question options:

True

False

False

A student forgets to blank the spectrophotometer. How will this most likely affect the results?

Question options:

Absorbance readings will be artificially low.

There will be no effect.

The KMnO4 concentration will increase.

Absorbance readings will be inaccurate due to background interference.

Absorbance readings will be inaccurate due to background interference.

The standard curve is used to determine unknown concentrations from absorbance values.

Question options:

True

False

True

A soil sample produced a very dark purple solution after reacting with KMnO₄. What does this indicate?

Question options:

High active carbon

Low active carbon

High nitrogen levels

High phosphorus levels

Low active carbon

Two samples have the same absorbance, but one used twice as much soil mass. What is the likely outcome? (Hint: Think about the equation for the POXC equation).

Question options:

Both will have identical POXC values.

The sample with more soil will have lower calculated POXC per kg.

The sample with more soil will have higher absorbance.

Soil mass does not affect calculations.

The sample with more soil will have lower calculated POXC per kg.

You are a flower farmer. Despite optimal temperatures and rainfall, you notice your flowers are not producing as many blooms as in years past. What nutrient could your flowers be deficient in?

Question options:

Nitrogen

Phosphorus

Potassium

Phosphorus 

Relationship between KMnO₄ concentration, color intensity, absorbance, and active carbon in this lab.

KMnO4 is a deep purple solution, it reacts with active carbon and gets reduced and loses its color

So, soils with higher active carbon cause a greater decrease in color intensity

Higher absorbance on a spectrophotometer means a darker KMnO4 solution (less reaction with carbon) while lower absorbance means that more KMnO4 has reacted meaning there must have been higher active carbon in the soil.

A farmer tests two soils:

• Soil A: High POXC, medium nitrogen

• Soil B: Low POXC, high nitrogen

A. Which soil is likely to support long-term soil health better? Explain.
B. Suggest one management practice to improve the weaker soil.

A. Soil A is likely to support long-term soil health better. High POXC (active carbon) shows a greater amount of available carbon that increases microbial activity, improves soil structure, and enhances nutrient cycling over time. Even though its nitrogen is only medium, the strong biological activity helps sustain fertility long-term, whereas Soil B's low POXC suggests weaker microbial support and poorer long-term soil function despite its current high nitrogen.

B. To improve the weaker soil (Soil B), the farmer could add organic matter, such as compost to increase active carbon and support microbial activity.

Permanganate oxidizable carbon (POXC)

The carbon in the that is oxidized by potassium permanganate

**An indicator of soil health

As POXC increases, often so does plant productivity

Essential elements of fertilizer

Nitrogen→ Vegetative growth

Phosphorus→ Growth of roots and flowers

Potassium→ Disease resistance and fruit quality

You are a famer growing corn. Despite optimal temperatures and rainfall, you notice your plants have poor growth and a yellowing. Which nutrient are they most likely deficient in (N, P, or K)?

Nitrogen

You are a flower farmer. Despite optimal temperatures and rainfall, you notice your flowers are not producing as many blooms as in years past. What nutrient could your flowers be deficient in (N, P, or K)?

Phosphorus

You are a pumpkin farmer. Despite optimal temperatures and rainfall, you notice your pumpkins are not growing as large in previous years. What nutrient could your pumpkins be deficient in (N, P, or K)?

Potassium

What does K represent in the logistic growth model?

Question options:

Time

Population size

Carrying capacity

Intrinsic rate of growth

Carrying capacity

It is impractical to directly count every individual in a wild population for all of the following reasons except

Question options:

it may not be possible.

it is too expensive.

it is the most inaccurate method.

it is too time consuming.

it is the most inaccurate method.

Quadrat sampling is an appropriate sampling method for plants because

Question options:

plants only cover a small portion of habitats.

plants are motile.

plants always have uniform dispersions.

plants are non-motile.

plants are non-motile.

In order to obtain an accurate population estimate through quadrat sampling, you must select the coordinates

Question options:

of an area that is the easiest to sample.

at random.

of an area with the lowest population of the organism of interest.

of an area with the highest population of the organism of interest

at random.

(Actual population - Population Estimate)/Actual population X 100 represents the equation for

Question options:

logistic growth.

the lincoln index.

percent error.

a quadrat population estimate.

percent error.

The Lincoln Index allows us to make a mathematical estimate of the population size based on

Question options:

only the number of individuals caught during the capture phase that are marked.

only the number of individuals caught during the capture phase that are unmarked.

the ratio between marked and unmarked individuals captured.

the ratio between counted and uncounted individuals in a quadrat.

the ratio between marked and unmarked individuals captured

In lab this week we will use the Lincoln Index to estimate populations through mark and recapture. In the equation for the Lincoln Index, which of the following letters represents the number of marked organisms recaptured

Question options:

R

N

M

C

R

A population ecologist is most likely to study

Question options:

all of the abiotic factors of an ecosystem.

all of the individuals of one species in a given place at a given time.

how communities interact with the abiotic factors of the environment.

all the different populations in a given place at a given time.

all of the individuals of one species in a given place at a given time. 

Which of the following is not a likely outcome of high population density?

Question options:

increased competition

mortality decrease

reproduction decrease

excessive waste accumulation

mortality decrease

If a genetic defect impacted the waterbuck population by limiting the number of offspring the waterbucks could produce, which simulator setting below would change?

Time

Maximum per capita growth rate

Initial population size

Carrying capacity

Maximum per capita growth rate

Imagine more land is added to the park, allowing it to support up to 500 waterbucks. Which parameter would this change for your model?

Growth rate

Time

Population size

Carrying capacity

Carrying capacity

Quadrat sampling is most appropriate for

Question options:

Flying birds

Small, motile (moving) animals

Non-motile (non-moving) animals and plants

Large mammals

Non-motile (non-moving) animals and plants

You want to determine the population size of a snail population in your neighborhood. You catch 20, and mark them. A week later, after they have had a chance to disperse into the population, you catch 15, and 6 have marks on them, what is the estimated size of the population?

N = (M*C) / R

N = estimated Number of individuals in the population

M = number of individuals captured and Marked

C = total number Captured the second time (with and without a mark) in second capture

R= number of individuals Recaptured (those with a mark)

Question options:

20

15

50

26

50

You are marking snails in your neighborhood, but the marks on half of your marked individuals wash off in the rain. How will your estimate of population size be affected by the snails losing their marks?

Question options:

The estimate will be too high

The estimate will be too low

No impact

The estimate will be too high 

Population

All the individuals of a single species that live together in a given area at a given time

Population ecology

The study of populations in relation to their environment

3 key features of populations:

Size- Number of individuals in an area

Density- Measurement of population per unit area or unit volume

Dispersion- The pattern of spacing among individuals within the boundaries of the population

Variables in a logistic growth curve (t, N0, r, K, N, dN/dt)

t = time

N0 = initial population size

r = max per capita growth rate

K = carrying capacity

N = population size.

dN/dt = population growth rate.

Density-dependent factors

Biotic factors that have an increasing effect as population size increases
• Predation
• Disease
• Competition

Density-independent factors

Abiotic factors in the environment that affect populations regardless of their density

• Weather/climate

• Fire

• Storms and flooding

Lincoln index for mark recapture

Formula: N = MC/R

N = total population size
C = total number of captured organisms in second capture
M = total number of organisms marked
R = number of marked individuals recaptured

If the herbivore population is regulated by the producers, this is called:

bottom-up regulation

If the herbivore population is regulated by the predators, this is called:

top-down regulation

If you were sampling a wild population of fish and the marked individuals were more visible to

predators than the unmarked individuals:

Would your population estimate would be too high or too low? (Think about the

equation!)

Too high → R(marked recaptured) is denominator and will decrease making N increase

Below (I - III) are three examples of population sampling techniques. For a-c below, select the

best sampling method for each scenario.

I. Quadrat sampling

II. Mark and Recapture Sampling (Lincoln Index)

III. Aerial Observations

a. Which of the sampling methods listed above (I – III) would be most appropriate for

monitoring a population of large -mouth bass (a type of fish) in a pond?

b. Which of the sampling methods listed above (I – III) would be most appropriate for

monitoring a population clover (a plant) in a field?

c. Which of the sampling methods listed above (I – III) would be most appropriate for

monitoring a population of elephants migrating across the savannah in Africa?

a) Mark and Recapture Sampling (Lincoln Index)

b) Quadrat sampling

c) Aerial Observations

The beneficial results that come from successful ecosystem interactions are defined as

Question options:

Food webs

Food chains

Ecosystem services

Biodiversity

Ecosystem Services

Which of the following statements best describes heterotrophs?

Question options:

Heterotrophs convert inorganic materials into organic materials.

Heterotrophs feed on organic materials and convert it into different organic materials.

Heterotrophs feed on organic materials from consumers only.

Heterotrophs convert organic materials into inorganic materials.

Heterotrophs feed on organic materials and convert it into different organic materials

A group of individuals of the same species occupying a given area at a given time is most commonly known as

Question options:

a community.

an ecosystem.

a biome.

a population.

a population.

Which of the following is a biotic factor?

Question options:

disease-causing bacteria

temperature

wind

soil-particle size

disease-causing bacteria

Less energy is available at each successive trophic level of the pyramid of energy because __________.

Question options:

only a fraction of the available food is captured by the next trophic level

some of the food that is eaten cannot be digested

only a portion of the food that is digested becomes part of the organism's body

all of the above

all of the above

Which of the following trophic levels in not paired with its corresponding definition?

Question options:

Decomposer - an organism that is responsible for breaking down organic "waste" from other organisms

Primary consumer - carnivore; organism that converts organic material (through the consumption of animals) into different organic material

Teritary consumer - carnivore; organism that converts organic material (through the consumption of other animals) into different organic material

Producer - organism that convert inorganic material into organic material

Primary consumer - carnivore; organism that converts organic material (through the consumption of animals) into different organic material

The three levels of biodiversity are

Question options:

Producer, consumer, and decomposer.

plant, animal, and microbe.

community, population, and ecosystem.

ecological, species, and genetic

ecological, species, and genetic

Which of the following best represents the concept of the "tragedy of the commons"?

Question options:

A conservation area where wildlife protection is the top priority.

A shared grazing land where individual farmers place as many cows as possible.

A privately-owned farm where the owner maximizes crop yield to benefit the community.

A public park where visitors responsibly dispose of their trash.

A shared grazing land where individual farmers place as many cows as possible.

Explain how commercial fishing can be an example of "tragedy of the commons".  In your explanation, be sure to define "tragedy of the commons"

The Tragedy of the Commons occurs when individuals overexploit a shared, unregulated resource for short-term gain, ultimately depleting it for everyone. Commercial fishing is a "tragedy of the commons" because individual fishers are incentivized to harvest as many fish as possible for immediate profit, eventually depleting the shared population faster than it can reproduce and leaving the entire industry with nothing

In Ecosystem Jenga (Activity # 6), card # 18 states, "Lots of clear sunny days. More sunlight reaches the ocean surface. Insert one green block back into matching color level." Why did this action result in the addition of a single green block to the Jenga tower?

Question options:

It is the result of abiotic factors decreasing the biomass of producers.

It is the result of biotic factors increasing the biomass of primary consumers.

It is the result of biotic factors increasing the biomass of producers.

It is the result of abiotic factors increasing the biomass of producers.

It is the result of abiotic factors increasing the biomass of producers.

Laws of thermodynamics

1st law: energy is neither created nor destroyed but only changed in form.

2nd law: usable energy is reduced with each energy transfer.

Species Diversity

# of species
– how many species are present
– how abundant is each species

Genetic Diversity

variety of genotypes
– e.g. corn/maize - different versions of genes in individual species

Ecological diversity

community complexity
– how many niches, trophic levels, etc.

Pollution

The introduction of harmful substances or energy (like heat, light, or noise) into the natural environment at a rate faster than they can be dispersed or safely stored

Examples: Acid, organic, thermal, pharmaceutical, salt

Acid pollution

Sulfur and nitrogen oxides react with air in the atmosphere (and potentially the terrestrially via run-off) to form sulfuric and nitric acids which will reenter the environment via rain.
***Side effect of air pollution from industry

Organic Pollution

Organic compounds that are resistant to environmental degradation
Examples: Pesticides, fertilizers (nutrient) , detergents, sewage, farm run-off

Can persist and accumulate causing biomagnification

Eutrophication

The process by which a body of water acquires a high concentration of nutrients, especially phosphates and nitrates

Promote excessive growth of algae.

– Algae die, decompose, increase organic material...therefore resulting in oxygen depletion

Bioaccumulation

Accumulation of a chemical at a rate greater than that at which the substance is lost

• obtained from external environment or food

Thermal pollution

Degradation of water quality by any process that changes the ambient water temperature

Cause: use of water as a coolant by power plants and industrial manufacturers

Pharmaceutical pollution

Refers to the presence of medications—like antibiotics, hormones, painkillers, and antidepressants—in the environment, especially in water systems.