Ecology and field Biology Exam 1

What 8 things defines something as alive?

1. ability to assimilate/use energy

2. ability to respond to their environment

3. ability to maintain a relatively stable internal tempt

4. ability to reproduce

5. ability to grow and develop

6. have evolved from other living things

7. are highly organized

8. are composed of one or more cells who's information is encoded in DNA

***What are the steps of the scientific method?***

1. observe a phenomena

2. narrow focus to a specific question

3. formulate a TESTABLE hypothesis

4. design an experiment to TEST the hypothesis

5. analyze data and display results in figures/tables

6. conclude how the findings relate to the big picture

Does an investigator have to finish ALL the steps of the scientific method before starting over?

no

What is a variable?

an adjustable condition in an experiment, may be biotic or abiotic

what is the difference between biotic and abiotic variables

Biotic factors are living things; such as plants, animals, and bacteria

Abiotic factors are non-living components; such as water, soil and tempt.

What makes a good hypothesis?

It is specific, testable and falsifiable.

What is the difference between and independent and dependent variable?

the independent variable is the variable that is changed/manipulated (x axis)

the dependent variable is the variable being measured, its outcome depends on the independent variable (y axis)

When should you use bar graphs or histograms?

when comparing groups

when should you use line graphs or scatter plots?

to show trends across time, tempt, or to show relationship between 2 variables

what is the difference between a scientific theory and a non-scientific theory?

non-scientific theories are typically ideas or hypotheses

a scientific theory is a general set of principles supported by evidence that explains some aspect of nature

What is the chief unifying principle of biology?

evolution

What is ecology?

The study of interactions between organisms and their environment

What are the four different levels of study in ecology and how are they defined?

1. INDIVIDUAL: study of individual organisms in an environment

2. POPULATION: all members of a species in the same geographic area at the same time

3. COMMUNITY: populations of all species in the same geographic area

4. ECOSYSTEM: community of organisms and the physical environment they interact with (abiotic and biotic factors)

What is the difference between a food chain and a food web?

a FOOD CHAIN is a linear transfer of energy between organisms in an ecosystem from producers to consumers

a FOOD WEB is the interconnection of all food chains in a particular ecosystem

What are the different trophic levels?

PRIMARY PRODUCERS: autotrophs convert solar energy to chemical energy (plants)

PRIMARY CONSUMERS: herbivores

SECONDARY CONSUMERS: carnivores that eat herbivores

TERTIARY CONSUMERS: carnivores that eat other carnivores

What trophic level are humans typically found in?

secondary or tertiary consumers

What are the four main elements that make up the human body?

C arbon

H ydrogen

O xygen

N itrogen

_____ elements make up _____ % of the human body.

10

99%

What are the 8 properties of water?

POLARITY: water has different charges within the molecule (pulls apart ions)

COHESION: water clings to each other because of attractive forces (allows water to travel up plant stems/trunks)

SURFACE TENSION: water molecules pack tightly at the surface because they are not attracted to air (allows organisms to "walk" on water)

UNIVERSAL SOLVENT: water can dissolve more substances that any other liquid (can pull compounds apart)

DENSER in liquid form (organisms can survive under the ice of frozen water since ice floats)

HIGH HEAT OF VAPORIZATION (organisms cool by sweating)

HIGH SPECIFIC HEAT means more energy required to raise tempt 1°C (water acts as a buffer to tempt changes)

MOLECULAR ATTRACTION: hydrophobic (molecules contain water) vs hydrophillic

What is cell theory?

all living organisms are made up of one or more cells

cells come from existing cells

What are the 3 modern additions to cell theory?

1. cells use energy and have metabolism

2. all cells have similar chemical composition

3. most cells have genetic information in the form of DNA

Which domains are made up of prokaryotic cells and which one has eukaryotic cells?

bacteria and archaea are prokaryotic

plants, animals, fungi, and protists are eukaryotic

Why are cells so small and what is the benefit of having greater surface area to volume ratio?

cells are small because it increases their surface area to volume ratio, meaning they are more efficient in transporting stuff in and out of the cell

What is a virus and why are they considered nonlivng?

a virus is an infectious particle consisting of an RNA/DNA genome enclosed in a protein coat (capsid), it must HIJACK cells to reproduce

it is considered nonliving because it CANNOT REPRODUCE or CARRY OUT METABOLIC PROCESSES outside the host cell

What domain of life contains extremophiles?

archaea

What are the 5 main differences between prokaryotic and eukaryotic cells?

PROKARYOTIC

small

always single celled

no nucleus

no membrane bound organelles

single, circular chromosome

EUKARYOTIC

large

often multicellular

nucleus

membrane bound organelles

multiple, linear chromosomes

Identify and define the two theories for the origin of organelles.

AUTOGENESIS: infoldings of prokaryote plasma led to compartmentalization

ENDOSYMBIOSIS: one organism engulfed the other, which then became an organelle

What are the 3 differences between plant and animal cells?

Animal cells do not contain a cell wall, vacuoles, or chloroplasts

What are the first two laws of thermodynamics?

1. Energy can neither be created nor destroyed, only transformed into different forms.

2. As energy moves from order to disorder, entropy increases and heat is lost

What is the difference between an exergonic and endergonic reaction? What type of reaction are cellular respiration and photosynthesis considered?

EXERGONIC: reactants contain more energy than products (cellular respiration)

ENDERGONIC: products contain more energy than reactants (photosynthesis)

What is the purpose of cellular respiration? What are the reactants? The products?

PURPOSE: to produce energy (ATP)

REACTANTS: glucose and oxygen

PRODUCTS: carbon dioxide, water, ATP, and heat

What are the four thermoregulatory strategies animals employ?

ENDOTHERMIC: body tempt maintained by metabolic heat

ECTOTHERMIC: body tempt controlled by external sources

POIKILOTHERM: animals who's body tempt fluctuates with the environment

HOMEOTHERM: animals with relatively constant body tempt

What is the difference between vasodialation and vasoconstriction?

VASODIALATION: widening of superficial blood vessels

VASOCONSTRICTION: constricting of superficial blood vessels

What is the difference between conduction and convection?

CONDUCTION: the direct transfer of heat

CONVECTION: transfer of heat via movement of air/water across a surface

What are some MORPHOLOGICAL adaptations to thermoregulation?

hair

feathers

fat (blubber)

What are some BEHAVIORAL adaptations to thermoregulation?

basking

burrowing

huddling

What are some PHYSIOLOGICAL adaptations to thermoregulation?

sweating