FB Unit 1 - Biochemistry 2024-2025

Midterm Study Notes for Ecology, Energetics, and Inheritance

Definition: A biological community of interacting organisms and their physical environment.
Components: Biotic (living) and abiotic (non-living) factors interact within ecosystems.
Examples: Forests, deserts, wetlands, and coral reefs.

Primary Producers: Organisms that produce their own food (autotrophs); primarily plants and algae.
- Photosynthesis: Process of converting light energy into chemical energy (glucose).
Consumers: Organisms that obtain energy by feeding on others (heterotrophs).
- Types: Herbivores (primary consumers), carnivores (secondary and tertiary consumers), omnivores.
Decomposers: Organisms that break down dead organic material, recycling nutrients (e.g., fungi and bacteria).

Food Chain: A linear sequence of organisms through which nutrients and energy pass.
Food Web: A complex network of multiple food chains interlinked in an ecosystem.
Trophic Levels: Levels in a food chain, including producers, primary consumers, secondary consumers, and apex predators.

Symbiosis: Close interactions between two different species; can be mutualistic (beneficial to both), commensalistic (beneficial to one, neutral to the other), or parasitic (beneficial to one, harmful to the other).
Competition: Occurs when two species compete for the same resources (e.g., food, territory).
Predation: The predator-prey relationship where one organism hunts another for food.

Definition: Large geographic biotic community characterized by specific climate, flora, and fauna.
Examples: Tundra, tropical rainforest, grassland, desert, aquatic.

First Law: Energy cannot be created or destroyed, only transformed (Conservation of Energy).
Second Law: Energy transformations are inefficient; energy tends to disperse (increased entropy).

Food Energy: Energy stored in food is measured in calories; energy decreases at each trophic level due to energy losses (e.g., metabolic processes, heat).
10% Rule: Only about 10% of energy is transferred from one trophic level to the next; the rest is lost in metabolic processes.

Primary Productivity: Rate at which primary producers create organic material; measured in light reactions of photosynthesis.
- Gross Primary Productivity (GPP): Total amount of organic material produced.
- Net Primary Productivity (NPP): GPP minus energy used in respiration (indicates available energy for consumers).

DNA: The molecule that carries genetic information; composed of nucleotides (A, T, C, G).
Gene: A segment of DNA that codes for a protein or functional RNA.

Laws of Segregation: Each organism carries two alleles for each trait, which segregate during gamete formation.
Laws of Independent Assortment: Genes for different traits are inherited independently from each other.

Dominant and Recessive Alleles: Dominant alleles mask the presence of recessive alleles in heterozygotes.
Codominance: Both alleles express equally in the phenotype (e.g., AB blood type).
Incomplete Dominance: Blending of traits in the phenotype (e.g., red and white flowers producing pink offspring).

Mutation: Changes in DNA sequence that can produce variations in traits.
Genetic Recombination: Occurs during meiosis, increasing variability in offspring.

Punnett Squares: A tool to predict the probability of genotypes from a cross.
Phenotypic Ratios: The observable traits resulting from genotypes in offspring, from controlled crosses.

Explain the role of primary producers in an ecosystem and the process through which they create energy.
Define and differentiate between GPP and NPP in the context of productivity.
How does the 10% rule explain energy transfer between trophic levels?
Describe Mendelian inheritance and provide an example using a Punnett square.
Discuss the significance of genetic recombination and mutation in populations.

Term	Definition
Ecosystem	A community of interacting organisms and their environment.
Trophic Level	The position an organism occupies in a food chain.
Primary Productivity	The rate at which primary producers create organic material.
Dominant Allele	An allele that masks the effect of a recessive allele in a heterozygote.
Codominance	A genetic scenario where both alleles express equally in the phenotype.