1st Quarter General Biology 1

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Questions and Answers

Which statement accurately describes the cell theory?

Cells are the minimum unit of life.

All cells arise from spontaneously generated material.

All living organisms are made up of one or more cells. (correct)

All forms of life are composed of multiple cells only.

What is the primary function of ribosomes in a cell?

Breaking down waste materials.

Modifying and sorting proteins.

Synthesis of proteins. (correct)

Generating adenosine triphosphate (ATP).

How do lysosomes contribute to cellular health?

They produce energy through cellular respiration.

They contain enzymes that digest waste materials. (correct)

They absorb nutrients from the environment.

They synthesize proteins for cellular functions.

What role does the Golgi apparatus play in a cell?

It modifies, sorts, and packages proteins. Signup and view all the answers

In which cellular process are mitochondria primarily involved?

Cellular respiration. Signup and view all the answers

What would likely happen if lysosomes were non-functional due to a mutation?

The cell could not effectively break down waste materials. Signup and view all the answers

What does the presence of numerous mitochondria in a cell generally indicate?

Increased metabolic activity. Signup and view all the answers

Why is the cell considered the basic unit of structure and organization in organisms?

Cells are the structural and functional units that can perform all life processes. Signup and view all the answers

What typically occurs in metaphase during mitosis?

Sister chromatids line up single-file along the metaphase plate. Signup and view all the answers

Which statement accurately describes a difference between mitosis and meiosis?

Sister chromatids separate during mitosis; homologous chromosomes separate during meiosis I. Signup and view all the answers

An error during anaphase II of meiosis may lead to which condition?

Trisomy in some gametes. Signup and view all the answers

What happens if a gamete with an extra chromosome fuses with a normal gamete?

It creates a zygote with three copies of that chromosome. Signup and view all the answers

Which genetic disorder is caused by a genetic mutation and not an issue with chromosome number?

Huntington's disease. Signup and view all the answers

Which of the following statements about hemophilia and sickle cell anemia is true?

Hemophilia affects blood clotting, while sickle cell anemia affects red blood cells. Signup and view all the answers

What is the primary role of meiosis in sexually reproducing organisms?

To produce gametes with unique genetic combinations. Signup and view all the answers

What characterizes the G0 phase of the cell cycle?

Cells are metabolically active but not dividing. Signup and view all the answers

What is the primary function of root hairs in plants?

To absorb water and nutrients from the soil Signup and view all the answers

Which phase of the cell cycle includes DNA replication?

S Phase Signup and view all the answers

During which stage of mitosis does the nuclear envelope begin to disintegrate?

Prophase Signup and view all the answers

What does the G1 phase of interphase primarily focus on?

Cell growth and organelle production Signup and view all the answers

Which of the following describes a consequence of premature entry into the S phase?

Uncontrolled cell proliferation Signup and view all the answers

What role do flagella play in bacterial cells?

Facilitating locomotion Signup and view all the answers

What is the primary purpose of the G2 phase in the cell cycle?

To check for DNA replication errors and repair them Signup and view all the answers

How many stages are there in mitosis?

Five Signup and view all the answers

What is the primary function of the Rough Endoplasmic Reticulum (RER)?

Synthesis of proteins Signup and view all the answers

What is the main component of the cell walls in most prokaryotic cells?

Peptidoglycan Signup and view all the answers

Which of the following is not a function of the Smooth Endoplasmic Reticulum (SER)?

Folding and modification of proteins Signup and view all the answers

What do prokaryotic cells primarily use for reproduction?

Binary fission Signup and view all the answers

Which substance is primarily stored in the Smooth Endoplasmic Reticulum (SER)?

Calcium ions Signup and view all the answers

What provides structural support and helps to maintain cell shape in prokaryotic cells?

Cell wall Signup and view all the answers

Which of the following statements is true regarding eukaryotic plant cell walls?

They contain cellulose as a primary component. Signup and view all the answers

What role does the RER play in relation to lysosomes?

It synthesizes proteins that are sent to lysosomes. Signup and view all the answers

What occurs to a cell when it is in a hypertonic environment due to high NaCl concentration?

Water exits the cell, leading to cell shrinkage. Signup and view all the answers

Which of the following best describes phagocytosis?

Cell membrane extension to engulf large particles. Signup and view all the answers

How does endocytosis differ from exocytosis?

Endocytosis pulls the membrane inward, while exocytosis pushes it outward. Signup and view all the answers

What is the primary distinction between phagocytosis and pinocytosis?

Phagocytosis targets large particles, whereas pinocytosis targets extracellular fluid. Signup and view all the answers

What is the consequence of dehydration in a cell due to osmotic stress?

The cell volume decreases leading to shrinkage. Signup and view all the answers

Which process is significantly more efficient for nutrient uptake?

Endocytosis is more efficient as it specializes in internalizing nutrients. Signup and view all the answers

In the process of plasmolysis, which one of the following is observed?

The plasma membrane detaches from the cell wall due to water loss. Signup and view all the answers

What is the outcome of water loss in animal cells under high salt conditions?

They shrink (crenate) and lose physiological function. Signup and view all the answers

Study Notes

Cell Theory

All living organisms consist of one or more cells, making cells the fundamental unit of life.
Cells serve as the smallest living units that perform life processes and form the structural and functional organization of organisms.
New cells arise from the division of pre-existing cells, highlighting cell division as vital for growth and reproduction.

Cellular Organelles

Ribosomes: Sites of protein synthesis, translating mRNA into protein by linking amino acids.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids from the endoplasmic reticulum (ER) for various cellular destinations.
Mitochondria: Known as the "powerhouses" of the cell, generate ATP through cellular respiration and regulate metabolism and apoptosis.
Lysosomes: Contain digestive enzymes for breaking down waste and cellular debris; important for recycling cell components.
Rough Endoplasmic Reticulum (RER): Studded with ribosomes for protein synthesis and modification, crucial for proteins secreted or sent to organelles.
Smooth Endoplasmic Reticulum (SER): Lacks ribosomes; synthesizes lipids, detoxifies drugs, metabolizes carbohydrates, and stores calcium ions.

Cell Wall Composition

Prokaryotic Cells: Most cell walls are made of peptidoglycan; archaea may consist of pseudopeptidoglycan or unique polysaccharides.
Eukaryotic Plant Cells: Primarily composed of cellulose, with additional components like hemicelluloses and pectin for rigidity and strength.

Cell Functions

Prokaryotic Cell Wall: Provides structural support, maintains shape, and protects against environmental stresses.
Eukaryotic Plant Cell Wall: Responsible for structural support, protection, shape maintenance, and regulates cell growth.

Reproductive Methods

Prokaryotic cells reproduce through binary fission, where one cell divides into two identical daughter cells.

Root Hairs and Flagella

Root Hairs: Extensions that increase surface area for water and nutrient absorption in plants.
Flagella: Whip-like structures aiding movement; propel animal cells and assist bacteria in locomotion.

Cell Cycle

Phases: Comprises Interphase (G1, S, G2) and Mitotic Phase (M Phase).
- Interphase: Cell grows and prepares for division; longest phase, includes G1, S, and G2 stages.
- Mitotic Phase: Divides into two daughter cells; includes mitosis and cytokinesis.

Mitosis vs. Meiosis

Mitosis aligns sister chromatids in a single row during metaphase, while meiosis aligns homologous chromosomes in pairs.
Mitosis promotes growth; meiosis ensures genetic diversity through unique gene combinations.

Errors in Meiosis

Errors during anaphase II can lead to gametes with abnormal chromosome numbers, potentially causing genetic disorders such as Down syndrome or Turner syndrome.

Genetic Disorders

Huntington's Disease: A genetic mutation causing neurodegenerative problems.
Hemophilia: Affects blood clotting mechanisms.
Sickle Cell Anemia: Impairs red blood cell morphology and function.

Osmotic Stress

High NaCl concentrations can cause water loss from cells, leading to crenation in animal cells and plasmolysis in plant cells, affecting cell function and structure.

Endocytosis and Exocytosis

Phagocytosis: Cell "eats" large particles or microorganisms; common in immune cells.
Pinocytosis: Cell "drinks" extracellular fluid and small molecules; important for nutrient absorption.
Exocytosis: Vesicles fuse with the membrane to release substances outside the cell.
Endocytosis: Membrane invaginates to internalize substances, reducing membrane surface area.

Nutrient Uptake Efficiency

Endocytosis is generally more efficient for nutrient uptake as it allows cells to selectively absorb necessary substances.

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Description

Explore the fundamental concepts of cell theory in this quiz, focusing on the three main postulates that define all living organisms. Understand the significance of cells as the basic units of life and their role in biological structure and function. Test your knowledge on cell theory and its implications for biology.