Biology Basics: Homeostasis & Cell Theory

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Questions and Answers

What is the primary goal of homeostasis in living organisms?

To maintain relatively constant internal conditions (correct)

To promote cell division and growth

To eliminate waste from the body

To increase metabolic rates

Which of the following is NOT an example of a condition maintained through homeostasis?

Nutrient absorption (correct)

Blood glucose levels

Body temperature

Heart rate

How does the body primarily respond to an increase in internal temperature?

By increasing heart rate to distribute heat

By inducing sweating to cool the skin (correct)

By increasing blood glucose levels

By dilating blood vessels to retain heat

What characterizes a failure in homeostatic regulation?

Dysregulation leading to diseases or disorders Signup and view all the answers

Which mechanism is primarily associated with maintaining blood glucose levels?

Hormonal regulation through insulin and glucagon Signup and view all the answers

What is the main purpose of the control group in an experiment?

To provide a standard for comparison Signup and view all the answers

Which variable is manipulated by the researcher in an experiment?

Independent Variable Signup and view all the answers

Which of the following is considered a characteristic of living organisms?

Internal constancy or homeostasis Signup and view all the answers

What describes the role of producers in an ecosystem?

They absorb sunlight or chemicals to create their own food Signup and view all the answers

How does homeostasis relate to internal conditions in living organisms?

It maintains stable internal environments despite external changes Signup and view all the answers

Which of the following best represents a detritivore's role in an ecosystem?

Feeding on dead organisms and organic matter Signup and view all the answers

What is a defining feature of the dependent variable in an experiment?

It is the factor that is measured and affected Signup and view all the answers

In a vaccination trial, which group receives the treatment being tested?

Experimental Group Signup and view all the answers

What is the primary function of cohesion in water molecules?

To move water from roots to leaves. Signup and view all the answers

Why is water considered a good solvent?

It is a polar molecule, allowing it to dissolve many substances. Signup and view all the answers

What characteristic of water contributes to ice floating?

Water becomes less dense when frozen. Signup and view all the answers

What is the main source of energy provided by carbohydrates?

Providing immediate energy for cells. Signup and view all the answers

Which biological molecules are primarily responsible for controlling chemical reactions?

Proteins. Signup and view all the answers

What type of reaction do enzymes that are classified as catabolic perform?

Break down larger molecules into smaller ones. Signup and view all the answers

Which of the following is NOT a function of proteins?

Cell wall formation. Signup and view all the answers

Which macromolecule is primarily responsible for storing genetic information?

Nucleic acids. Signup and view all the answers

Study Notes

Homeostasis

Maintains relatively constant internal conditions
Examples include body temperature, blood glucose levels, heart rate

Hierarchy of Life

Atom
Molecule
Organelle
Cell
Tissue
Organ
Organ System
Organism
Population
Community
Ecosystem
Biosphere

Original Cell Theory

All organisms are made up of one or more cells
The cell is the fundamental unit of life
All cells come from preexisting cells

Atomic Structure

Atoms consist of protons, electrons, and neutrons.
Protons have a positive charge and are located in the nucleus.
Electrons have a negative charge and are located in shells surrounding the nucleus.
Neutrons have no charge and are located in the nucleus.
First electron shell holds up to 2 electrons
Second electron shell holds up to 8 electrons
Third electron shell holds up to 8 electrons

Periodic Table of Elements

The number of protons in an element is its atomic number.
The atomic number defines the element.
Atomic mass is the atomic number plus the number of neutrons.

Bulk Elements in Living Organisms

Oxygen
Nitrogen
Carbon
Hydrogen

Acids and Bases

Acids have a high concentration of hydrogen ions (H+) and a low concentration of hydroxide ions (OH-).
Bases have a low concentration of hydrogen ions (H+) and a high concentration of hydroxide ions (OH-).
Neutral solutions have equal concentrations of hydrogen and hydroxide ions.
The pH scale measures the acidity or alkalinity of a solution.
A pH of 1-6 is acidic, 7 is neutral, and 8-14 is basic.

Chemical Bonds

Atoms form chemical bonds to fill their outer electron shell.
Covalent bonds involve the sharing of electrons between atoms.
Ionic bonds involve the transfer of electrons between atoms.
Hydrogen bonds are weak attractions between a hydrogen atom and an electronegative atom, such as oxygen or nitrogen.

Properties of Water

Cohesion: Water molecules are attracted to each other due to hydrogen bonding. This property helps water move from plant roots to leaves.
Adhesion: Water molecules are attracted to non-water substances. This property helps water adhere to surfaces.
Temperature Regulation: Water can absorb and release a lot of heat without changing temperature drastically. This helps organisms maintain a stable body temperature.
Solvent: Water is a good solvent because it is a polar molecule. This allows it to dissolve many substances, which is important for transporting solutes in the bloodstream.
Density: Water is less dense as a solid than as a liquid. This is why ice floats, which allows life to exist in water even during cold temperatures.

Organic Molecules

Carbohydrates
Proteins
Lipids
Nucleic Acids

Carbohydrates

The monomer of carbohydrates is a monosaccharide.
Carbohydrates are the main source of energy for living organisms.
Examples include sugars, starches, and cellulose.

Proteins

The monomer of proteins is an amino acid.
Proteins have a variety of functions in living organisms, including:
- Structural support
- Enzyme catalysis
- Hormone regulation
- Storage
- Transport
- Cell signaling

Lipids

Contain fats, oils, waxes, and steroids.
Important for energy storage.
Phospholipids are a major component of cell membranes.

Nucleic Acids

The monomers of nucleic acids are nucleotides.
DNA and RNA are examples of nucleic acids.
Nucleic acids store and transmit genetic information.

Enzymes

Enzymes are proteins that speed up chemical reactions.
Anabolic reactions join smaller molecules to create larger molecules.
Catabolic reactions break down larger molecules into smaller molecules.
Enzymes have a specific shape that only fits the substrate it acts on, called enzyme-substrate specificity.

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Description

Test your knowledge on fundamental biological concepts including homeostasis, the hierarchy of life, and the original cell theory. This quiz covers essential topics such as atomic structure and the periodic table of elements, providing a comprehensive overview of biology fundamentals.