Biology 102 Exam 1 Study Guide

Flashcards cover metric prefixes and base units, microevolution concepts, levels of biological organization, and key vocabulary from the Biology 102 notes.

What are the metric prefixes you must know?

kilo-, centi-, milli-, micro.

What base units are used in the metric system for length, volume, and mass?

Length: meter (m); Volume: liter (L); Mass: gram (g).

What type of metric conversion problems should you be able to calculate?

Conversions among metric units as practiced in lab (e.g., m to cm, L to mL).

What is microevolution?

Evolutionary changes within a population or species, reflected in changes in allele frequencies over generations.

What are genes?

Units of heredity made of DNA that encode instructions for traits.

What are alleles?

Alternative forms of a gene at a given locus.

Natural selection — define and give an example.

Differential survival and reproduction due to heritable variation; e.g., rock pocket mouse coat color matching lava rock reduces predation.

Gene flow — define and give an example.

Movement of alleles into or out of a population via migration; e.g., pollen transfer between plant populations.

Genetic drift (bottleneck effect) — define and give an example.

Random changes in allele frequencies, especially after a bottleneck; e.g., bottleneck reduces genetic diversity (as seen in cheetahs).

Mutation — define and give an example.

Change in DNA that creates new alleles; e.g., a mutation leading to lactase persistence (lactose tolerance) in humans.

Sexual selection — define and give an example.

Natural selection driven by mating success; e.g., male peacock tails attracting mates.

At what level of biological organization does microevolution occur?

Population.

Is natural selection random?

No.

Are mutations random?

Yes; mutations occur randomly with respect to the organism's needs.

Are mutations good, bad, neutral, or all of these?

Mutations can be beneficial, neutral, or deleterious; most are neutral or harmful; beneficial mutations are relatively rare.

Explain natural selection using the rock pocket mouse (a) what natural selection is, (b) what the selective pressure was, (c) why the trait provides a survival/reproductive advantage.

Natural selection is differential survival and reproduction due to heritable traits. In this example, predation creates selective pressure; mice with coat color matching lava rock blend in and suffer less predation, increasing survival and reproduction.

Explain natural selection using lactose tolerance in humans (a) what natural selection is, (b) what the selective pressure was, (c) why lactase persistence provides an advantage.

Natural selection is differential survival and reproduction due to heritable traits. The selective pressure is dairy consumption selecting for individuals with lactase persistence; those who can digest lactose in adulthood gain energy and nutrients, increasing survival and reproductive success.

subatomic particles

Particles smaller than atoms (protons, neutrons, electrons) that make up atoms.

atoms

Basic units of matter composed of protons, neutrons, and electrons; defined by the number of protons (atomic number).

molecules

Two or more atoms bonded together; can be elements or compounds.

organelles

Membrane-bound or specialized subunits inside cells (e.g., mitochondria, nucleus).

tissues

Groups of similar cells that perform a specific function.

organs

Structures made of two or more tissue types that perform a specific function.

organ systems

Groups of organs that cooperate to perform major body functions (e.g., circulatory, digestive).

species

Group of organisms that can interbreed and produce fertile offspring; a basic unit of classification.

population

Group of individuals of the same species living in the same area.

community

All populations of different species living and interacting in the same area.

ecosystem

A system formed by biotic and abiotic components in an area, including energy flow and nutrient cycles.

biotic

Living components of an ecosystem (plants, animals, microorganisms).

abiotic

Nonliving physical and chemical factors (temperature, water, sunlight, minerals).

biosphere

The global sum of all ecosystems; the zone of life on Earth.

What are some examples of abiotic factors in an ecosystem?

Examples include temperature, precipitation, sunlight, wind, soil moisture, pH, salinity.