General Zoology (Laboratory) Flashcards

Flashcards covering the Scientific Method, cell structure, organelles, cell cycle, and central dogma concepts from the lecture notes.

What is the Scientific Method?

A step-by-step process used by scientists to explore observations, solve problems, and answer questions.

List the steps of the Scientific Method in order.

Observation; Defining the problem; Formulating a hypothesis; Experimentation; Results and conclusions.

What is Observation in the Scientific Method?

The first step involving what is directly or indirectly seen, heard, tasted, smelled, or felt; leads to questions.

What is a hypothesis?

An educated guess about the connection between variables; a temporary answer or explanation.

What is Experimentation in the Scientific Method?

Laboratory work to gather accurate facts to test the hypothesis and answer the problem.

What are Results and Conclusions?

The results provide the final answer or explanation to the problems.

What is the cell membrane (Plasma Membrane)?

A thin, flexible barrier surrounding the cell; selectively permeable; mainly a lipid bilayer with embedded proteins.

What is cytoplasm?

The jelly-like substance inside the cell that surrounds all organelles; includes the cytosol.

What is the cytoskeleton and its function?

A network of fibers (microtubules, microfilaments, intermediate filaments) that maintains cell shape, secures organelles, and enables movement.

Name major organelles and their primary functions.

Mitochondria: energy (ATP) production; ER: intracellular transport (rough has ribosomes for protein synthesis, smooth synthesizes lipids); Golgi apparatus: modifies, sorts, and packages proteins; Lysosomes: enzymes that break down waste; Ribosomes: sites of protein synthesis; Centrioles: role in animal cell division.

What is the nucleus?

The control center of the cell that contains genetic material (DNA); regulates gene expression and mediates DNA replication.

What is the Nuclear Envelope?

A double membrane that surrounds the nucleus and separates it from the cytoplasm.

What is the nucleoplasm?

The jelly-like fluid inside the nucleus that supports and protects its contents.

What is the nucleolus?

A dense, round structure inside the nucleus that makes ribosomal RNA and assembles ribosomes.

What is chromatin?

A network of DNA and proteins that carries genetic information and condenses into chromosomes during cell division.

What are somatic and germinal cells?

Somatic cells are body cells; germinal cells are reproductive cells.

What are mitosis and cytokinesis?

Mitosis is the division of the nucleus; cytokinesis is the division of the cytoplasm; results in two daughter cells.

What is Interphase?

The longest phase of the cell cycle; prepares the cell for mitosis; DNA is in chromatin form, not yet visible as chromosomes.

What happens in G1 phase?

Cells grow in size and synthesize all cellular contents except chromosomes.

What happens in S phase?

DNA is replicated and centrosomes duplicate.

What happens in G2 phase?

The cell double-checks duplicated chromosomes for errors and produces proteins for spindle fibers.

What happens in Prophase?

Chromosomes condense, the nuclear membrane and nucleolus disappear, centrosomes move to opposite poles forming spindle fibers.

What happens in Metaphase?

Chromosomes align at the equatorial plate; centromeres attach to spindle fibers.

What happens in Anaphase?

Centromeres divide; sister chromatids separate and move to opposite poles.

What happens in Telophase and Cytokinesis?

Chromosomes uncoil; nuclear membrane and nucleolus reform; cleavage furrow forms and the cell splits into two daughter cells.

What is the Central Dogma of Life?

Replication (DNA to DNA), Transcription (DNA to RNA), and Translation (RNA to Protein).

What is DNA replication?

DNA makes an exact copy of itself to pass genetic information to daughter cells.

What is transcription?

A gene segment of DNA is copied into messenger RNA in the nucleus.

What is translation?

mRNA is read by ribosomes in the cytoplasm; tRNA brings amino acids, which are linked into a protein.

What is a gene?

A segment of DNA that codes for a specific protein or functional RNA molecule.

What are the components of a DNA nucleotide?

A deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), or Thymine (T).

What are the components of an RNA nucleotide?

A ribose sugar, a phosphate group, and one of four nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), or Uracil (U).