Biol CSUF Final Notes

Parts of Cell Theory

All living things are made of cells; cells are the basic unit of life; all cells come from other cells.

Prokaryotic Cell

No nucleus; DNA in nucleoid; no membrane-bound organelles; has a cell wall and capsule.

Eukaryotic Cell

Has nucleus; membrane-bound organelles; includes animal and plant cells.

Differences: Plant vs Animal Cell

Plant: cell wall, chloroplasts, large central vacuole. Animal: no cell wall, no chloroplasts, small vacuoles.

Interphase

Prepares cell for division; includes G1, S, and G2 phases.

G1 Phase

Cell grows, gathers materials, and prepares for DNA replication.

S Phase

DNA replication occurs; centrosomes begin forming mitotic spindles.

G2 Phase

Cell replenishes energy, reorganizes contents, prepares for mitosis.

G1 Checkpoint

Checks cell size, DNA damage, energy, and molecule supply before S phase.

G2 Checkpoint

Ensures DNA is fully replicated and undamaged before mitosis.

Mitosis

Division of nucleus into two identical daughter nuclei.

5 Stages of Mitosis

Prophase, Prometaphase, Metaphase, Anaphase, Telophase.

Cytokinesis

Physical separation of cytoplasm; cleavage furrow in animals, cell plate in plants.

Virus

Non-living; protein capsid, genome (DNA/RNA), may have envelope; needs host to replicate.

Bacteriophage

Virus that infects bacteria by inserting DNA.

Viral Replication Cycle

Attachment → Entry → Replication → Assembly → Release (lysis or budding).

Vaccine Types

Weakened live, killed virus, viral parts (subunits); live gives longer immunity.

Central Dogma of Biology

DNA → RNA → Protein.

Transcription

DNA is copied into mRNA in the nucleus.

Translation

mRNA is used to build proteins at the ribosome.

Codon-Anticodon Pairing

A-U, T-A, C-G, G-C during transcription.

Amino Acid

Building block of protein; carried by tRNA.

Peptide

Chain of 2-50 amino acids.

Protein

50+ amino acids, folded and functional.

Allele

A version of a gene.

Genotype

Genetic makeup (e.g., Aa, AA, aa).

Phenotype

Physical traits (e.g., red fur, white fur).

Dominant vs Recessive

Dominant masks recessive; recessive only shows if both alleles are recessive.

X-linked Trait

Gene located on the X chromosome; often affects males more.

Mutation Types

Silent, missense, nonsense, frameshift, point mutations.

Meiosis

Creates 4 genetically unique gametes with half the DNA (haploid).

Crossing Over

Prophase I event; homologous chromosomes swap DNA for variation.

Independent Assortment

Chromosomes line up randomly in metaphase I, increasing variation.

Random Fertilization

Adds variation; any sperm can fertilize any egg.

Innate Immunity

Immediate, non-specific defense (skin, mucous, stomach acid).

Adaptive Immunity

Specific, learned response; includes memory cells.

B Cells

Made in bone marrow; produce antibodies.

T Cells

Made in thymus; help regulate and kill infected cells.

Cytotoxic T Cells (Tc)

Kill infected cells; stimulate immune responses.

Secondary Immune Response

Faster and stronger due to memory cells.

What does a circle represent in a pedigree chart?

A female individual.

What does a square represent in a pedigree chart?

A male individual.

What does a shaded symbol represent in a pedigree chart?

An affected individual (has the trait/disease).

How can you tell if a trait is autosomal recessive in a pedigree?

It can skip generations; affected individuals often have unaffected parents.

How can you tell if a trait is X-linked recessive in a pedigree?

More males than females are affected; no male-to-male transmission.

What is the purpose of antiviral drugs?

To inhibit viral replication and control symptoms.

How do vaccines prevent viral infections?

By training the immune system to recognize and respond to the virus.

What is the main difference between a live attenuated vaccine and a killed vaccine?

Live attenuated vaccines use weakened virus; killed vaccines use inactivated virus or parts.

What makes the secondary immune response faster than the primary?

Memory B and T cells quickly recognize the pathogen.

What is the role of memory cells in immunity?

They persist after infection and enable rapid response if re-exposed.

What is the complement system in immunity?

A group of proteins that help antibodies clear pathogens.

What is humoral immunity?

An immune response involving B cells and antibodies.

What is immunodeficiency?

A weakened or absent immune response (e.g., HIV/AIDS).

What is hypersensitivity?

An overreaction of the immune system to harmless substances (e.g., allergies).