Biology Theories: Cell, Gene, Evolution

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Questions and Answers

What does Cell Theory state about living organisms?

Cells are the basic unit of life. (correct)

Only eukaryotic cells exist in nature.

Cells can spontaneously generate.

All organisms are made of tissues.

Which of the following is a characteristic of all cells?

They have a nucleus.

They can perform photosynthesis.

They can move independently.

They contain a plasma membrane. (correct)

What is one key difference between prokaryotic and eukaryotic cells?

Prokaryotic cells contain membrane-bound organelles.

Prokaryotic cells lack a defined nucleus. (correct)

Eukaryotic cells have DNA, while prokaryotic cells do not.

Eukaryotic cells are smaller than prokaryotic cells.

Which principle explains the changes in living organisms over time?

Evolutionary Theory Signup and view all the answers

What role does DNA play in cells?

It acts as a store of genetic material. Signup and view all the answers

Which of the following is NOT one of the Five Principles of Biology?

Molecular Theory Signup and view all the answers

Which statement about gene theory is accurate?

It controls the characteristics of living organisms through genes. Signup and view all the answers

What is the significance of homeostasis in living organisms?

It helps maintain equilibrium within physiological systems. Signup and view all the answers

What is the primary role of DNA in cells?

To serve as hereditary information for cell division Signup and view all the answers

How do eukaryotic cells primarily reproduce?

Meiosis and Mitosis Signup and view all the answers

Which of the following is NOT a function requiring energy in cells?

Composition of lipids Signup and view all the answers

What does the genome refer to in living organisms?

The sum of all genetic material in an individual Signup and view all the answers

What is a key aspect of cell theory regarding the activities of cells?

All cells are similar in chemical composition and metabolic activities Signup and view all the answers

How is genetic information transmitted across generations?

By the storage and transmission of genes Signup and view all the answers

Which process allows cells to maintain homeostasis?

Energy transformation Signup and view all the answers

What role do sub-cellular structures play in the functionality of cells?

They facilitate the basic chemical and physiological functions of the cell Signup and view all the answers

What is a primary characteristic of prokaryotic cells?

DNA free in the cytoplasm Signup and view all the answers

Which process is essential for maintaining homeostasis in living organisms?

Equilibrium between interdependent elements Signup and view all the answers

Which of the following is a supporting field for evolutionary theory?

Developmental biology Signup and view all the answers

What is a key feature of eukaryotic cells that distinguishes them from prokaryotic cells?

Presence of a nuclear membrane Signup and view all the answers

In what way do eukaryotic cells differ in their replication compared to prokaryotic cells?

Eukaryotic cells reproduce by meiosis and mitosis. Signup and view all the answers

How does thermodynamics relate to biological systems?

Energy can be transferred but not created or destroyed. Signup and view all the answers

Which of the following processes is associated with maintaining oxygen levels on Earth?

Photosynthesis and respiration balance Signup and view all the answers

Which statement accurately describes prokaryotic cells?

They lack a nuclear membrane. Signup and view all the answers

What do we mean by the 'Central Dogma' in biology?

The flow of genetic information from DNA to RNA to protein. Signup and view all the answers

What phenomenon does entropy refer to in thermodynamics?

Disorder that always increases in a closed system. Signup and view all the answers

Which organelle is responsible for ATP production?

Mitochondria Signup and view all the answers

Which of the following is a function of the Golgi apparatus?

Protein processing and secretion Signup and view all the answers

What best describes the function of lysosomes?

Degrades internalized material Signup and view all the answers

Which structural component provides mechanical support and signaling in cell-to-cell contacts?

Desmosomes Signup and view all the answers

What characterizes prokaryotic cells?

Absence of membrane-bound organelles Signup and view all the answers

Which type of cell does NOT contain a cell wall?

Cardiac Myocytes Signup and view all the answers

What is the role of the smooth endoplasmic reticulum?

Lipid synthesis Signup and view all the answers

What aspect of cells allows compartmentalisation and the efficiency of specific processes?

Functional barriers Signup and view all the answers

In multicellular organisms, what is the advantage of cell specialization?

Perform specific functions efficiently Signup and view all the answers

Which of the following structures maintain low pH for enzymatic functions?

Lysosome Signup and view all the answers

What type of cells contain chloroplasts?

Photosynthetic eukaryotic cells Signup and view all the answers

What is the primary function of the cytoskeleton?

Provides structure and enables movement Signup and view all the answers

Which organelle is involved in RNA transcription?

Nucleus Signup and view all the answers

What mechanism allows selective transport in and out of the nucleus?

Nuclear pores Signup and view all the answers

Study Notes

Cell Theory

All living organisms are composed of cells.
Cells are the fundamental units of life.
Cells arise from pre-existing cells.
Cells share similar chemical composition and metabolic activities.
Energy transfer within cells occurs.
All basic chemical and physiological functions are carried out inside cells.
Cell activity depends on the activities of sub-cellular structures.

Gene Theory

Characteristics of living organisms are controlled by genes passed on from one generation to the next.
Genetic information is stored, expressed, and utilized by the genome.
Gene expression mediates the growth and behavior of organisms.
DNA is passed on from one generation to the next.

Evolutionary Theory

Characteristics of living organisms change over time due to natural selection and adaptation.
Diversity of life has evolved over time through mutation, selection, genetic change, and inheritance.
This theory is supported by various fields including molecular genetics, developmental biology, biochemistry, and paleontology.

Homeostasis

Homeostasis is the tendency to maintain equilibrium between interdependent elements of processes and systems.
Positive and negative feedback mechanisms are essential for maintaining homeostasis.

Laws of Thermodynamics

Energy can neither be created nor destroyed, but can be transferred from one form to another.
Within an isolated system, entropy always increases.

Prokaryotic Cells

Lack a nucleus and other membrane-bound organelles.
DNA is a single circular chromosome without histones.
The only organelle present is the ribosome.
Cell division occurs through binary fission.
They have a cell wall and a plasma membrane.
They are usually single-celled.
Examples include bacteria and archaea.

Eukaryotic Cells

Have a nucleus and other membrane-bound organelles.
DNA is organized in multiple linear chromosomes with histones.
Have a complex cytoplasm and cytoskeleton.
Cell division occurs through mitosis and meiosis.
They have a cell wall in some cases (plants and fungi).
They have a plasma membrane.
They can be single-celled or multicellular.
Examples include protists, fungi, plants, and animals.

Unicellular vs. Multicellular Organisms

Unicellular organisms carry out all functions of life within one cell.
Multicellular organisms have specialized cells that perform different functions and are organized into tissues.

Cell Specialisation

Cells in multicellular organisms specialize in performing particular jobs.
This specialization allows for efficient and complex functioning.
Compartmentalization within cells creates specialized microenvironments.

Functional Barriers: Membranes

Membranes are semi-permeable barriers that enable compartmentalization.
They regulate the transport of molecules entering and exiting compartments.

Nucleus

The nucleus contains DNA.
It is enclosed by the nuclear membrane.
Nuclear pores control transport into and out of the nucleus.
It is the site of DNA replication and RNA transcription.

Cytoskeleton

Provides structural support, enables movement, and facilitates organization within the cell.
It is composed of microtubules, actin filaments, and intermediate filaments.

Protein Synthesis and Trafficking

Protein synthesis occurs on ribosomes attached to the rough endoplasmic reticulum (RER).
Proteins are processed and secreted by the Golgi apparatus.
Lipid synthesis occurs in the smooth endoplasmic reticulum (SER).

Mitochondria and Chloroplasts

Mitochondria are the sites of ATP production (energy).
Chloroplasts are involved in photosynthesis and energy production.
Both are double-membraned organelles.

Lysosome and Proteosome

Lysosomes degrade internalized material and endogenous proteins.
Proteosomes degrade proteins.

Cell-to-Cell Contacts

Adhesive molecules enable cells to maintain contact and interact with the extracellular matrix.
Integrins link the cytoskeleton to the extracellular matrix.
Adherins junctions and desmosomes provide mechanical support and signaling.
Gap junctions allow communication between cells through small molecule passage.
Tight junctions form junctions that prevent even ion passage.

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Description

Test your knowledge on three fundamental biological theories: Cell Theory, Gene Theory, and Evolutionary Theory. Explore how cells function, how traits are inherited, and how species evolve over time. This quiz covers key concepts and principles that are foundational to understanding biology.