General Biology

Nucleic acids

macromolecules essential for the storage and transmission of genetic information in living organisms. Made up of simple unit of nucleotides.

Cholesterol

fatty substance that is essential for building cells and producing certain hormones in the body.

Carbohydrates

organic compounds that contain carbon, hydrogen, and oxygen.

Haemoglobin

a molecule in the blood that helps distribute oxygen to the tissues in the body.

Hydrolysis

when polymers can also be broken down into monomers.

Monosaccharides

the simplest form of carbohydrate, consisting of a single sugar molecule..

DNA

a molecule that carries genetic instructions. It has a double helix structure made of nucleotides containing adenine, thymine, cytosine, and guanine..

Monomers

the individual building blocks of a polymer.

Electrons

negatively charged (-) particles.

RNA

A molecule similar to DNA that plays a role in protein synthesis and carries genetic information. It is single-stranded and contains uracil instead of thymine.

Protons

positively charged (+) particles.

Neutrons

neutral particles as they do not carry any electric charge.

Phospholipids

contain two fatty acid "tails "and one negatively charged phosphate "head.

Polymers

chains of building blocks in macromolecules.

Glucose

an important part of the food we eat, and it is the product made by plants during photosynthesis.

Amino acids

building blocks of proteins.

Side chain polarity

affects whether an amino acid is more hydrophobic or more hydrophilic.

Polysaccharides

a complex carbohydrate composed of multiple monosaccharide (simple sugar) units linked together.

Acidic solution

contains a lot of hydrogen ions (H+).

Atoms

the unit of life and are the building blocks of the physical world.

pH scale

logarithmic and represents a tenfold change in hydrogen ion concentration.

alpha helix

a common secondary structure in proteins, characterized by a tightly coiled, helical shape.

fatty acid

type of molecule that serves as a building block of lipids, which are a class of biological molecules that include fats, oils, and phospholipids.

disaccharide

type of carbohydrate composed of two monosaccharide molecules joined together through a chemical bond known as a glycosidic bond.

polypeptide

a chain of amino acids linked together by peptide bonds.

triglyceride

type of lipid (fat) and is composed of three fatty acid molecules chemically linked to a glycerol molecule.

Proteins

large molecules made of amino acids, serving various roles such as enzymes for chemical reactions, structural support, and signaling in the body.

Lipids

diverse group of organic molecules that are insoluble in water but soluble in nonpolar solvents.

ph scale

a numeric scale ranging from 0 to 14 that measures the acidity or alkalinity of a solution

covalent bond

formed when electrons are shared between atoms.

Adhesion

the attraction between different types of molecules or surfaces.

Elements

pure substances that consist of only one type of atom.

What process breaks a disaccharide into two monosaccharides by adding water?

Hydrolysis

How does lipid saturation affect its structure and function

• Saturated fats: No double bonds, straight structure, solid at room temperature (e.g., butter).

• Unsaturated fats: One or more double bonds, bent structure, liquid at room temperature (e.g., olive oil).

Cohesion

when molecules of the same substance stick together.

Surface Tension

the force that makes the surface of a liquid like a 'skin'( invisible layer that resists external forces) due to the attraction between the liquid's molecules.

beta-plated sheet

a protein secondary structure where adjacent amino acid chains align in a sheet-like formation, held together by hydrogen bonds.

Neutrons

uncharged particles.

Phospholipids

type of lipid molecule composed of two fatty acid chains, a glycerol backbone, and a phosphate group.

What theory did Charles Darwin formulate?

the Theory of Evoltuion

What is a scientific theory?

a well-supported explanation of a natural phenomena backed independently by extensive research and evidence.

Why are theories accepted as facts

it has strong empirical support.

Empirical

based on observation and experience rather than theory or pure logic.

Falsifiable

An idea that can be tested and potentially proven wrong based on evidence.

Extensive

a large area

Exponentially

more and more rapidly

Components of a Scientific Theory

Observations, inference, hypothesis

Who formulated the Theory of Evolution?

Charles Darwin.

Why is the Theory of Evolution important?

It explains how species change over time through natural selection.

What is a scientific theory?

A well-supported explanation of natural phenomena, Backed by extensive data Verified by scientists.

Why is a scientific theory accepted as fact?

It has strong empirical support from repeated experiments and observations.

"What does ""empirical"" mean?"

Based on observation or experience rather than theory or logic.

"What does ""falsifiable"" mean?"

An idea that can be tested and potentially proven wrong based on evidence.

"What does ""extensive"" mean?"

Covering a large area or range.

"What does ""exponentially"" mean?"

Increasing more and more rapidly.

What is an observation in science?

Using the senses to describe a phenomenon.

What would happen if all individuals in a species successfully reproduced?

Populations would grow exponentially.

What happens to population sizes over time?

They remain stable, except for seasonal changes.

How do limited resources affect populations?

They restrict population growth.

What did Darwin notice about variation within populations?

Individuals show extensive variation, most of which is inherited.

What is an inference in science?

A conclusion or opinion drawn from observed facts or evidence.

What did Darwin infer about survival?

Survival is not randomIndividuals with advantageous traits are more likely to survive and reproduce.

What is “survival of the fittest”?

The principle that individuals with traits best suited to their environment reproduce more successfully. Also called differential reproductive success.

What is a hypothesis?

A testable and falsifiable explanation for an observation.

What was Darwin’s hypothesis about evolution?

Natural selection is the driving mechanism behind evolutionary change.

How does natural selection lead to evolution?

Individuals with advantageous traits pass them on, causing changes in species over generations.

What are the three main stages of early development in animals?

Zygote → Embryo → Fetus

Why do embryos provide evidence for evolution?

Many species have similar-looking embryos, suggesting they share a common ancestor.

Why do embryos provide evidence for evolution?

Many species have similar-looking embryos, suggesting they share a common ancestor.

What features do embryos of different species share?

Features like gill slits and tails, even in species that do not have them as adults.

What features do embryos of different species share?

Features like gill slits and tails, even in species that do not have them as adults.

What are fossils?

Remnants or traces of past organisms preserved in Earth's crust. The deeper you dig, the simpler and fewer fossils are found.

What is an artifact?

An object that gives clues about past life but is not a fossil.

What is biogeography?

The study of how and why species are distributed across different geographic locations.

What are homologous structures?

Similar structures inherited from a common ancestor that may have different functions.

What is a vestigial structure?

A structure inherited from an ancestor that has lost its original function but still exists in the organism.

What are embryological structures?

Developmental features that show conservation of homeotic genes, indicating common ancestry.

What are molecular homologies?

Similarities in genes, proteins, and protein products inherited from a common ancestor.

Descent with Modification

The concept that evolution explains the unity and diversity of life.

Evolution

The change in genetic makeup of a population over time.

Adaptation

A trait, structure, function, or behavior that gives the organism an evolutionary advantage.

Phenotype

Physical expression of traits.What you can see or measure in an organism.Physical or observable.

Hardy-Weinberg Theorem

A scientific rule assuming no evolution, predicting allele frequencies stay the same unless acted on by certain factors.Assumes no evolution and predicts allele frequencies stay the same unless affected by certain factors.

Hardy & Weinberg

Named after G.H. Hardy (mathematician) Wilhelm Weinberg (physician), Both developed the theorem.

Theorem

A scientific principle that explains a pattern based on logical reasoning and evidence.

Null

Assumes nothing changes, meaning no evolution.

Null Hypothesis

Describes what would happen if evolution wasn’t happening.

Alleles make up genotypes

Genotypes are made up of alleles that interact to form an organism’s traits.

Hardy-Weinberg Postulates (Conditions for Equilibrium)

Conditions needed for a population to stay in equilibrium without evolving.

Large Population

Reduces the impact of random changes (genetic drift).

No Mutations

No new alleles are introduced.

Random Mating

No sexual selection; all individuals have an equal chance to pass on genes.

No Gene Flow

No migration that introduces or removes alleles.

No Natural Selection

No traits are favored; survival is random.

Genetic Drift

Random changes in allele frequencies, especially in small populations.

Mutation

Introduces new alleles into the gene pool.

Sexual Selection

Some traits are more attractive, causing certain alleles to be passed on more.

Gene Flow

Immigration/emigration brings in or removes alleles.

Natural Selection

Environment favors beneficial traits for survival.

Types of Genetic Drift

• Bottleneck Effect: when a small group survives a disaster, leading to limited genetic diversity.

• Founder Effect: Small group breaks off from larger population, forming a new population with different allele frequencies.