General Biology 1: Cell Theory, Cell Structure, Tissues, and Cell Division

A comprehensive set of Q&A flashcards covering the key concepts from the notes on cell theory, cell structure, plant and animal tissues, and cell division (mitosis and meiosis).

What is the ascending order of the Organization of Life?

Atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms.

Name the three classical postulates of the Cell Theory.

1) All living things are made of cells. 2) Cells are the basic unit of life. 3) Cells arise from pre-existing cells.

In what year was the Cell Theory formally established?

1839.

Who contributed the third postulate to the Cell Theory?

Robert Virchow.

Approximately how many cells are in the human body?

About 37.2 trillion cells.

What is the main difference between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a true nucleus and membrane-bound organelles; eukaryotic cells have a true nucleus and membrane-bound organelles.

What is the region containing genetic material in prokaryotic cells called?

Nucleoid.

What type of ribosomes do prokaryotes have?

70S ribosomes (50S and 30S subunits).

Name two external structures commonly found on prokaryotic cells.

Capsule and flagellum (also pili/fimbriae).

What is the function of the capsule in prokaryotes?

Protection and adhesion to surfaces.

What is the function of flagella in prokaryotes?

Locomotion (movement).

What are the three main components of the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules.

What is the function of a cell membrane?

Separates the cell from the external environment and regulates movement of substances in and out.

What is the nucleus and its main roles?

A prominent organelle that houses DNA and controls growth and reproduction.

What is the function of mitochondria?

Powerhouse; produces ATP through cellular respiration.

What is the Rough Endoplasmic Reticulum (RER) responsible for?

Synthesis and modification of proteins destined for secretion or the plasma membrane.

What is the function of the Smooth Endoplasmic Reticulum (SER)?

Synthesis of lipids and steroids; major components of the cell membrane.

What is the Golgi apparatus’ role?

Packages proteins from the RER into vesicles and sorts/secretes them.

What is the function of lysosomes?

Break down cellular debris and transport waste within the cell.

Which organelle is responsible for photosynthesis in plants?

Chloroplast.

What is the function of the cytoplasm?

Jelly-like fluid where many metabolic activities occur (not explicitly required, but commonly taught).

Name three major plant organelle structures unique to plant cells.

Cell wall, chloroplasts, and large central vacuole.

What is the function of the cell wall in plants?

Provides structure and protection; prevents bursting under pressure (composed of cellulose in plants).

What is the function of a vacuole in plant cells?

Maintains water pressure and stores nutrients.

What is the function of xylem in plants?

Transports water and dissolved minerals from roots to all parts of the plant; hollow at maturity.

What are the two main types of xylem cells?

Tracheids and vessel elements.

What is the function of phloem in plants?

Transports sugars from the leaves to other parts of the plant.

Name the three major plant tissue systems.

Dermal, Ground, and Vascular tissues.

What is the function of parenchyma cells?

Carry out most metabolic processes and store organic products; typical plant cells with large vacuoles.

Which plant tissue provides structural support for growing parts?

Collenchyma.

Which plant tissue provides structural support with lignin and cutin?

Sclerenchyma.

What are the primary functions of xylem and phloem tissues?

Xylem transports water/minerals; Phloem transports sugars.

What is the function of guard cells in leaves?

Regulate stomatal openings to control gas exchange and transpiration.

Name the four main animal tissue types.

Epithelial, Muscle, Nervous, Connective.

What is the primary function of epithelial tissue?

Protects the body, lines cavities, and can secrete fluids and prevent water loss; includes simple/stratified and shapes squamous/cuboidal/columnar.

What are the three muscle tissue types?

Cardiac, Skeletal, and Smooth muscle.

What is the role of nervous tissue?

Neurons transmit electrical impulses to control body responses.

What is connective tissue’s main purpose?

To support, anchor, and connect various parts of the body.

What is a neuron?

A nerve cell that transmits electrical impulses; composed of dendrites, a nucleus, and an axon.

What is cell differentiation?

A process where cells with the same genes acquire different structures and functions through gene expression.

Name examples of specialized cells listed in the notes.

Root hair cell, Red blood cells, Xylem vessel, Sperm cells, Guard cells, Neurons.

What is a root hair cell specialized for and why?

Elongated to increase surface area for nutrient and water absorption.

What is the role of red blood cells (RBCs)?

Carry oxygen from the lungs to body tissues; have a biconcave, flexible shape to maximize hemoglobin delivery.

What are the components of a sperm cell’s structure and function?

Head (nucleus and acrosome) for fertilization; Midpiece contains mitochondria for energy; Tail (flagellum) for movement.

What are the stages of mitosis?

Prophase, Metaphase, Anaphase, Telophase (PMAT).

What happens during cytokinesis?

Division of the cytoplasm to form two genetically identical daughter cells; cells then return to interphase.

How many cell divisions occur in meiosis, and how many daughter cells are produced?

Two divisions (Meiosis I and Meiosis II) producing four haploid daughter cells.

What is the key difference between meiosis I and meiosis II?

Meiosis I reduces chromosome number by separating homologous chromosomes; Meiosis II is mitosis-like and separates sister chromatids.

List the stages of Meiosis I.

Prophase I, Metaphase I, Anaphase I, Telophase I (with sub-stages Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis during Prophase I).

What occurs during crossing over and in which stage does it happen?

Exchange of chromosome material between non-sister chromatids during Prophase I (Pachytene stage).