[G12] GENBIO Q1

Spontaneous Generation Theory (Abiogenesis)

The idea that living organisms can arise from non-living matter.

Zacharias Janssen and Hans Lippershey

Who created the first compound microscopes?

Robert Hooke

He observed box-like structures he calls “cells” in his work Micrographia.

Antonie van Leeuwenhoek

He describes “animalcules” (microorganisms) in pond water, marking the first observation of living cells.

Matthias Schleiden

He concludes that all plant tissues are composed of cells, laying the groundwork for a unified cellular concept in biology.

Theodor Schwann

He states that all living things consist of cells and that cells are the basic units of structure and function in organisms

Louis Pasteur

He contributed to the cell theory by proving that living things are products of cells, which are living things

Rudolph Virchow

Completed the third statement prominent in the Cell Theory, believing that all cells arise from other cells: Omnis cellula e cellula

10 trillion cells.

How many cells does the human body have?

Plasma/Cell Membrane

A phospholipid bilayer embedded with proteins, lipids, and carbohydrates.

Cytoplasm

The entire region of thick solution between the plasma membrane and the nucleus.

Nucleus

Cell control center; Stores genetic material (DNA) and manages gene expression/directs cell activity.

Nuclear pores (nucleopore)

Permit the passage of ribosomal subunits and mRNA out of the nucleus into the cytoplasm.

Nucleoplasm/Cytosol

The semifluid matrix

Nuclear envelope

Separates the nucleus from the cytoplasm

Nucleolus

Involves the synthesis, processing, and assembly of ribosomal RNA (rRNA) and ribosomal proteins into ribosomal subunits.

Chromatin

Packages DNA into a compact structure that fits within the cell nucleus, while also regulating gene expression and DNA replication.

Ribosomes

Found in both prokaryotes and eukaryotes; Sites of polypeptide (protein) synthesis; Complexes of rRNA and protein

Rough Endoplasmic Reticulum (RER)

Studded with bound ribosomes; synthesizes and folds secretory and membrane proteins.

Smooth Endoplasmic Reticulum (SER)

Lacks ribosomes; synthesizes lipids (steroids, phospholipids), detoxifies drugs, and stores calcium.

Golgi Apparatus

Series of flattened sacs (cis- and trans-faces); modifies, sorts, and packages proteins and lipids for transport.

Mitochondria

Double membrane “powerhouse” of the cell; generates ATP via cellular respiration

Chloroplasts (plants and algae)

Contain thylakoids and chlorophyll; convert light energy into chemical energy (photosynthesis).

Lysosomes

Membrane-bound sacs of hydrolytic enzymes; digest macromolecules, old organelles, and pathogens.

Peroxisomes

Contain oxidative enzymes; break down fatty acids and detoxify harmful compounds; produce and degrade H₂O₂.

Cytoskeleton

Maintains cell shape, enables intracellular transport, and drives cell movement.

Nucleoid region.

Where is the DNA in Prokaryotic Cells located?

Melanocytes

Produce the hormone melanin, which is responsible for skin pigmentation (color) and photoreception of the skin and eyes

Keratinocytes

Generate a protein called keratin, which helps make the skin an effective layer of protection for the body.

Muscle Cells

Responsible for the contraction and relaxation of various organs (heart, lungs, live, stomach). Also known as myocytes.

Leukocytes (WBC)

Play a significant role in fighting against foreign bodies that may enter the body.

Erythrocytes (RBC)

Carry oxygen as it binds with the hemoglobin and carbon dioxide as a waste product.

Thrombocytes (Platelets)

Prevent bleeding due to the proteins on their surface that allow them to stick to breaks in the blood vessel wall and to stick to each other.

Nerve Cells (neurons)

Receives sensory input from the external world, sends motor commands, and transforms/relays electrical signals at every step in between; insulated by glial cells through myelination.

Fat Cells

Store energy in the form of fat, cushion internal organs, and insulates the body.

Bone Cells

Responsible for locomotion (movement), support and protection of soft tissues, calcium and phosphate storage, and the harboring of bone marrow.

Cancer Cells

They work to destroy the body through rapid spreading as they develop decreased sensitivity to anti-growth signals and proliferate quickly in the absence of stop signals

Stem Cells

Originate as unspecialized cells and can develop into specialized cells that can be used to build specific organs or tissues. They can divide and replicate many times to replenish and repair tissue.

Vascular Tissue

Transport substances like water, minerals, and sugar from on extreme end of the plant to the other.

Xylem Tissue

Receives water and nutrients from the plantsoil interface to the stems and leaves. It then provides mechanical support for the water and nutrients transported upward and for the plant itself.

Phloem Tissue

Acts as a transport system for soluble organic compounds such as sugar and proteins within vascular plants.

Dermal Tissue

Covers and protects the plant, and controls gas exchange and water absorption (in roots). It also prevents evaporative water loss in the stem and leaves of plants due to the presence of a waxy covering called cuticle

Parenchyma Cells

They make up plant leaves and are the sites of photosynthesis and sugar or starch storage in roots

Sclerenchyma Cells

They provide structural support in growing regions of the shoot system being long with thin cells that retain the ability to stretch and elongate.

Collenchyma Cells

They provide structural support in mature stems after growth has stop due to its toughness and inability to stretch

Cell Modification

It is a process that occurs after cell division, where the newly formed cells are structurally modified so that they can perform their function efficiently and effectively.

Gene Expression

The process by which the instructions in our DNA are converted into a protein.

DNA

Controls the way cells function. It also determines what type of specialized cells will be made.

RNA

Translates and transcribes the DNA code into proteins (the structures of a cell).

Cllium

Small hair-like protuberance on the outside of eukaryotic cells. They are primarily responsible for locomotion (motile), either of the cell itself or of fluids on the cell surface

Flagellum

A whip-like structure that acts primarily as an organelle of locomotion in the cells of many living organisms.

Villus

Small finger-like projections located in the walls of the small intestine. Their function is to increase the surface area in order to maximize the absorption of digested food.

Biconcave

A structural modification in red blood cells that allows them to efficiently transport oxygen

Root hair cells

Modified epidermal cells of the roots which has a long and narrow protrusion. It has a large vacuole with lots of mitochondria in the cytoplasm.

Guard cells

These are cells surrounding a stoma that help to regulate the rate of transpiration – evaporation of water in plants – by opening and closing the stomata

Plant Cuticle

An extracellular hydrophobic layer that covers the aerial epidermis of all land plants, protecting against desiccation and external environmental stresses. It contains cutin, a waxy, water-repellent substance.

Necrosis

A cell may die by things that may harm them such as toxic chemicals or physical injuries

Apoptosis

Some cells are programmed or destined to die

G1 Phase (First Gap)

The cell grows and accumulates the building blocks of chromosomal DNA and the associated proteins, as well as enough energy reserves to complete the task of replicating each chromosome in the nucleus.

S Phase (Synthesis)

DNA is replicated, which results in the formation of identical pairs of DNA molecules, sister chromatids, that are firmly attached to the centromeric region.

G2 Phase (Second Gap)

Cell grows more. The cell replenishes its energy, stores, and synthesizes proteins necessary for chromosome manipulation

G0 Phase

Some cell types are at rest, while some cells are constantly dividing. These cells may exit G1 and enter a resting state

Mitosis

A process of nuclear division in eukaryotic cells which is conventionally divided into four stages: prophase, metaphase, anaphase, and telophase.

Cytokinesis

Refers to the division of the cytoplasm which will occur during late telophase. It involves the formation of a cleavage furrow which pinches the cell into two for animal cells.

Cell Cycle Control System

Cell division timing and frequency are essential for proper growth, development, and maintenance in organisms

Checkpoints

Regulate progression with stop/go signals.

Protein kinases

Enzymes that activate/inactivate proteins via phosphorylation.

Cyclin-dependent kinases (Cdks)

This complex triggers processes essential for cell division (e.g., DNA replication, chromosome condensation).

Cytoskeleton

Structure that allows plant cells to remain rigid and support the plant

Differentiation

The process by which stem cells become specialized?