Biology: Genetics, Water Cycle, Ecosystems, and Evolution Key Concepts

Which compound is transcribed into protein?

DNA is transcribed into mRNA, which is then translated into protein.

What are the different types of mutation?

Substitution, insertion, deletion, and frameshift mutations.

What are the phases of the water cycle?

Evaporation, condensation, precipitation, and collection/runoff.

What happens during evaporation?

Liquid water changes into water vapor because of heat from the sun.

What happens during condensation?

Water vapor cools and forms clouds.

What happens after water vapor condenses in the sky?

Precipitation occurs as rain, snow, sleet, or hail.

What is ammonification in the nitrogen cycle?

Decomposers convert dead organisms and waste into ammonia.

What is primary succession?

The development of an ecosystem in an area with no soil, like after lava flow.

What is secondary succession?

The rebuilding of an ecosystem where soil already exists after a disturbance.

How does energy flow in an ecosystem?

Energy flows from the sun to producers and then to consumers and decomposers.

What is the direction of energy flow in an ecosystem?

Sun → producers → primary consumers → secondary consumers → tertiary consumers.

What are trophic levels?

The feeding levels in a food chain or food web.

What are the main trophic levels?

Producers, primary consumers, secondary consumers, and tertiary consumers.

How much energy is transferred between trophic levels?

About 10% is transferred to the next level.

How much energy is lost between trophic levels?

About 90% is lost as heat and metabolism.

What happens if biodiversity is lost in an ecosystem?

Ecosystems become less stable and more vulnerable to collapse.

What is water contamination?

Pollution of water by harmful substances.

What is eutrophication?

Excess nutrients cause algae growth that lowers oxygen in water.

What are the stages of the demographic transition model?

Pre-industrial, transitional, industrial, and post-industrial stages.

What was the Green Revolution?

A period of increased agricultural production using technology and improved crops.

What are stem cells?

Unspecialized cells that can develop into different cell types.

What is the most common source of adult stem cells?

Bone marrow.

What is cell specialization?

The process where cells develop specific structures and functions.

What is natural selection?

The process where organisms with beneficial traits survive and reproduce more.

How did Darwin's finches demonstrate natural selection?

Different beak sizes and shapes helped finches survive on different foods.

What are homologies?

Similar structures in different species that show common ancestry.

What is a gene?

A segment of DNA that codes for a trait or protein.

What is the process where genes are exchanged between chromosomes called?

Crossing over.

What is the difference between genotype and phenotype?

Genotype is genetic makeup; phenotype is physical appearance.

What is pedigree analysis?

The study of inherited traits using family charts.

How can you tell if a trait is dominant in a pedigree?

The trait usually appears in every generation.

How can you tell if a trait is recessive in a pedigree?

The trait can skip generations.

How can you tell if a trait is sex-linked in a pedigree?

The trait is often more common in one sex, especially males.