Bio Lab Midterm

Question 1

Define the scientific method.

Answer 1

A systematic process used to answer questions and test hypotheses through observation, experimentation, and analysis.

Question 2

Define cause and effect.

Answer 2

A relationship where one event (cause) directly produces another event (effect).

Question 3

Define experimental group.

Answer 3

The group in an experiment that receives the treatment or variable being tested.

Question 4

Define control group.

Answer 4

The group that does not receive the experimental treatment; used for comparison.

Question 5

Define independent variable.

Answer 5

The factor manipulated by the researcher.

Question 6

Define dependent variable.

Answer 6

The factor measured in response to changes in the independent variable.

Question 7

Define controlled variables.

Answer 7

Factors kept constant to ensure only the independent variable affects the results.

Question 8

Define correlation.

Answer 8

A relationship between two variables, not necessarily cause and effect.

Question 9

Define theory.

Answer 9

A well-supported explanation of natural phenomena based on evidence.

Question 10

Define principle.

Answer 10

A widely accepted truth or rule based on repeated experimental evidence.

Question 11

Explain the nature of scientific knowledge.

Answer 11

It is testable, based on evidence, subject to change, and self-correcting.

Question 12

Describe the basic steps of the scientific method.

Answer 12

Observation → Question → Hypothesis → Experiment → Data collection → Conclusion → Communication.

Question 13

State the purpose of an experiment.

Answer 13

To test a hypothesis by examining cause-and-effect relationships.

Question 14

Difference between cause/effect and correlation?

Answer 14

Cause/effect = one directly produces the other. Correlation = they occur together but one doesn’t necessarily cause the other.

Question 15

Describe the design of a typical research article in biology.

Answer 15

Abstract, Introduction, Methods, Results, Discussion, References.

Question 16

Plant adaptations in wet environments?

Answer 16

Large leaves, thin cuticles, shallow roots, drip tips.

Question 17

Plant adaptations in dry environments?

Answer 17

Thick cuticles, small/spiny leaves, deep roots, water storage tissues.

Question 18

Define convergent evolution.

Answer 18

Independent evolution of similar traits in unrelated species due to similar environments.

Question 19

Define epiphytes.

Answer 19

Plants that grow on other plants but are not parasitic.

Question 20

Define pollination.

Answer 20

Transfer of pollen from anther to stigma for fertilization.

Question 21

Define insectivorous plants.

Answer 21

Plants that trap and digest insects to obtain nutrients.

Question 22

Pollination in wet vs. dry environments?

Answer 22

Wet = often animal/insect pollination; Dry = often wind pollination or adaptations for fewer pollinators.

Question 23

Define magnification.

Answer 23

Enlargement of an object’s image.

Question 24

Define resolving power.

Answer 24

Ability to distinguish two objects as separate.

Question 25

Define contrast.

Answer 25

Difference in light intensity between an object and its background.

Question 26

Define field of view.

Answer 26

The visible area seen through the microscope.

Question 27

Define parfocal.

Answer 27

Ability to stay in focus when changing magnification.

Question 28

Define depth of field.

Answer 28

Thickness of the specimen that remains in focus at one time.

Question 29

Define working distance.

Answer 29

Space between the objective lens and specimen.

Question 30

How to correctly use/care for a microscope?

Answer 30

Carry with two hands, start on low power, use fine focus carefully, clean lenses with lens paper, cover after use.

Question 31

Function of parts of compound microscope?

Answer 31

Ocular lens: magnifies Objective lenses: primary magnification Stage: holds slide Light source: illumination Condenser: focuses light Coarse/fine knobs: focus

Question 32

How to make a wet mount?

Answer 32

Place specimen on slide, add drop of water, place coverslip at angle to avoid bubbles.

Question 33

Define cell.

Answer 33

Basic unit of life.

Question 34

Define cell theory.

Answer 34

All living things are made of cells, cells are the basic unit of life, and all cells come from pre-existing cells.

Question 35

Define prokaryotic.

Answer 35

Cells without nucleus or membrane-bound organelles (bacteria, archaea).

Question 36

Define eukaryotic.

Answer 36

Cells with nucleus and membrane-bound organelles.

Question 37

Define nucleus.

Answer 37

Organelle that stores DNA and controls activities.

Question 38

Define organelle.

Answer 38

Specialized structure within a cell with a specific function.

Question 39

Shared features of all cells?

Answer 39

Plasma membrane, cytoplasm, DNA, ribosomes.

Question 40

Prokaryotic vs. eukaryotic?

Answer 40

Prokaryotic: smaller, no nucleus/organelles. Eukaryotic: larger, nucleus, organelles.

Question 41

Plant vs. animal cells?

Answer 41

Plant: cell wall, chloroplasts, large vacuole. Animal: no cell wall, no chloroplasts, small vacuoles.

Question 42

Define solvent.

Answer 42

Substance that dissolves other substances.

Question 43

Define solute.

Answer 43

Substance dissolved in a solvent.

Question 44

Define selective permeability.

Answer 44

Membrane allows some substances to pass, blocks others.

Question 45

Define diffusion.

Answer 45

Movement of molecules from high to low concentration.

Question 46

Define osmosis.

Answer 46

Diffusion of water across a selectively permeable membrane.

Question 47

Define concentration gradient.

Answer 47

Difference in concentration between two regions.

Question 48

Define equilibrium.

Answer 48

Equal distribution of molecules across space.

Question 49

Structure of cellular membranes?

Answer 49

Phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.

Question 50

Difference between diffusion and osmosis?

Answer 50

Diffusion = all molecules. Osmosis = water only.

Question 51

Effect of molecular weight on diffusion?

Answer 51

Lighter molecules diffuse faster than heavier ones.

Question 52

Effect of temperature on diffusion?

Answer 52

Higher temperature increases diffusion rate.