Biology 2025 Spring Semester Final Study Guide

Biology 2025 Spring Semester Final Study Guide Flashcards

What are mutations?

Changes in the DNA sequence that can be spontaneous or induced by mutagens.

What are Mendel's Laws?

Law of Segregation and Law of Independent Assortment, which explain how traits are inherited.

What does homozygous mean?

Having two identical alleles for a particular gene.

What does heterozygous mean?

Having two different alleles for a particular gene.

Where are sex-linked genes located?

On the sex chromosomes (usually the X chromosome).

What is the difference between Incomplete and Codominance?

Incomplete dominance: phenotype is a blend of both alleles; Codominance: both alleles are fully expressed.

Human blood is an example of what?

Multiple alleles and codominance.

Define haploid.

Having a single set of chromosomes (n).

Define diploid.

Having two sets of chromosomes (2n).

What is meiosis?

A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes.

What process produces gametes?

Meiosis

What is nondisjunction?

The failure of chromosomes to separate properly during cell division.

What is cloning?

Producing a genetically identical copy of an organism; asexual reproduction.

What is a karyotype?

A display of the chromosome pairs of a cell arranged by size and shape. A normal human karyotype has 46 chromosomes.

Describe sickle cell disease.

A genetic disorder caused by a mutation in the hemoglobin gene, leading to abnormally shaped red blood cells and various symptoms.

What is a pedigree?

A chart that shows the inheritance of a trait in a family.

List the evidence for evolution.

Fossil record, comparative anatomy, comparative embryology, molecular biology. F, fossil, A, anatomical, M, molecular, E, embryological

What is the Theory of Evolution?

The process by which modern organisms have descended from ancient organisms.

How do homologous structures differ from analogous structures?

Homologous structures: share a common ancestry but may have different functions. Analogous structures: have similar functions but do not share a common ancestry.

What are vestigial structures?

Structures that have lost their original function and indicate evolutionary relationships.

What is natural selection?

The process by which organisms better adapted to their environment tend to survive and reproduce more successfully.

What were Darwin's contributions to the theory of evolution?

He proposed the mechanism of natural selection as the driving force behind evolution.

What is fitness?

The ability of an organism to survive and reproduce in its environment.

What defines a species?

A group of organisms that can interbreed and produce fertile offspring.

What is extinction?

The state or process of a species becoming extinct; mass extinction refers to a period of widespread extinction events.

What is speciation?

The process by which new species arise from existing species.

How is punctuated equilibrium different from phyletic gradualism?

Punctuated equilibrium: long periods of stasis interrupted by rapid bursts of evolutionary change. Phyletic gradualism: slow and steady evolutionary change.

What are superbugs?

Bacteria that are resistant to several types of antibiotics.

What is a cladogram?

A branching diagram showing the cladistic relationship between a number of species.

What is a phylogenetic tree?

A branching diagram showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics.

What is the Law of Superposition?

In undisturbed rock layers, the oldest layers are at the bottom and the youngest layers are at the top.

Define erosion.

The process by which soil and rock are removed from the Earth’s surface by wind, water, ice, or gravity.

Define weathering.

The breakdown of rocks at the Earth’s surface through mechanical and chemical processes.

What are the 4 types of fossils?

Original remains, mold fossils, cast fossils, and trace fossils.

What are ecosystem disturbances?

Events that disrupt the structure and function of an ecosystem. Examples include fires, floods, and human activities.

How is ecosystem stability linked to biodiversity?

Higher biodiversity generally leads to greater ecosystem stability.

Define albedo.

The reflectivity of a surface. High albedo: snow; Low albedo: asphalt.

What are invasive species?

Non-native species that cause harm to the environment, economy, or human health.

What is the difference between conduction, convection, and radiation?

Conduction: heat transfer through direct contact; Convection: heat transfer through the movement of fluids; Radiation: heat transfer through electromagnetic waves.

What is a feedback mechanism?

A process where the output of a system influences its input.

List possible climate change solutions.

Reducing greenhouse gas emissions, renewable energy, carbon sequestration.

What is the largest contributor to climate change?

Greenhouse Gas Emissions

What is a keystone species?

A species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

What is the AMOC?

Atlantic Meridional Overturning Circulation - a system of ocean currents

What is the Gulf Stream?

A warm and swift Atlantic ocean current that originates in the Gulf of Mexico, flows up the eastern coastline of the United States

What is the Coriolis effect?

The effect of Earth's rotation on the direction of wind and currents.

Explain the Greenhouse effect and why it is important

The process by which certain gases in the atmosphere trap heat, warming the Earth. It's important because it keeps the Earth warm enough to support life.

What are climate models and what can we learn from them?

Computer simulations of the Earth's climate system. They can help us understand past climate, predict future climate, and assess the impacts of climate change.

What are the effects of climate change?

Rising temperatures, changes in precipitation patterns, sea level rise, and shifts in organism distribution.