BIO EXAM

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

prokaryotic cells

do not have a nucleus or other membrane-bound organelles

Nucleus

Control center of the cell

ribosome

Makes proteins from amino acids

Rough ER (endoplasmic reticulum)

Folds and transports proteins made by attached ribosomes.

Golgi apparatus

Modifies, sorts, and packages proteins and lipids for shipping.

mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Lysosomes

Break down waste, old cell parts, and pathogens using digestive enzymes.

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

cell membrane

A cell structure that controls which substances can enter or leave the cell.

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Plasmids

small circular DNA molecules that replicate separately from the bacterial chromosome

flagella

A long, whip-like filament that helps in cell mobility.

dna structure and shape

a double helix (2 nucleotide strands connect like a ladder and are twisted like a corkscrew)

DNA replication

the process of making an exact copy of DNA before division (during s phase)

Complementary Base Pairing

In DNA, T pairs with A; G pairs with C;

RNA, U pairs with A and G pairs with C

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

RNA

A single-stranded nucleic acid that passes along genetic messages

mRNA (messenger rna)

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

tRNA (transfer RNA)

type of RNA that brings amino acids to the ribosome during protein synthesis

genetic code

The set of rules by which information encoded in mRNA is translated into proteins by ribosomes. It determines which amino acids correspond to specific codons in mRNA.

gene expression

The process by which information from a gene is used to synthesize a functional gene product, typically a protein. This involves transcription of DNA to mRNA and subsequent translation of mRNA to protein.

transcription

The process of copying a segment of DNA into RNA, producing messenger RNA (mRNA). This occurs in the nucleus for eukaryotes and the cytoplasm for prokaryotes.

translation

The process by which the sequence of codons in mRNA is read by ribosomes to assemble amino acids into a polypeptide chain, ultimately forming a protein.

karyotype

A karyotype is a complete set of chromosomes in an individual, arranged and displayed in a standard format, typically used to assess chromosomal abnormalities and determine sex.

binary fission

A form of asexual reproduction in which a single organism divides into two identical organisms. This process is commonly observed in prokaryotic cells.

interphase

The phase of the cell cycle where the cell prepares for division, including DNA replication and growth, consisting of G1, S, and G2 phases.

mitosis

A process of cell division that results in two genetically identical daughter cells, occurring after interphase and consisting of prophase, metaphase, anaphase, and telophase.

Prophase

The nuclear envelope begins to disintegrate, and the nucleolus disappears, making the chromosomes accessible

metaphase

Spindle fibers attach to the centromeres of each chromosome, pulling and lining them up single-file along the center of the cell.

anaphase

Each separated chromatid is now considered an individual chromosome and is hauled toward opposite ends (poles) of the cell

telophase

A new nuclear envelope and nucleoli re-form around each of the two new sets of chromosomes.

meiosis

a specialized type of cell division in sexually reproducing organisms that reduces the chromosome number by half, turning one diploid cell into four haploid gametes

diploid cells

Cells that contain two complete sets of chromosomes, with one set inherited from each biological parent.

haploid

Cells that contain only a single set of unpaired chromosomes. (half diploid)

genes

Segments of DNA that contain the instructions for producing specific proteins and determining inherited traits.

alleles

An allele is one of two or more alternative versions of a gene at a specific position (locus) on a chromosome

genotype

The entire genetic makeup or total DNA sequence inherited from an organism's parents

phenotype

the set of observable characteristics or traits of an organism

complete dominance

an allele that is regarded as dominant completely masks or suppresses the effect of a recessive allele in a heterozygous condition

incomplete dominance

a pattern of genetic inheritance in which a heterozygous individual displays an intermediate phenotype rather than fully expressing one dominant trait over a recessive one

codominance

a type of genetic inheritance in which two different alleles of a gene are both fully and equally expressed in a heterozygote, rather than one trait masking the other

monohybrid cross

A monohybrid cross is a genetic experiment or mating between two organisms that are heterozygous aiming for a single gene or trait

genotypic ratios

The proportion of different gene combinations (alleles) in the offspring

phenotypic ratios

The proportion of observable physical or physiological traits expressed by the offspring

pedigree charts

maps out the family relationships and tracks the genetic history or appearance of a specific trait across multiple generations of a family

pedigree symbols

• Squares (☐ / ⬛): Male

• Circles (○ / ●): Female

• Diamonds (◇): Unknown sex

• Shaded Shape: Individual shows the trait/phenotype being tracked (affected)

• Clear Shape: Individual does not show the trait (unaffected)

genetic mutations

a permanent change in the DNA sequence of an organism

GMOS

any plant, animal, or microorganism (such as bacteria or fungi) whose genetic material (DNA) has been altered using modern biotechnology or genetic engineering.

PCR

laboratory technique used to make millions to billions of copies of a specific segment of DNA from a very small initial sample.

recombinant dna

an artificially created DNA molecule formed by joining genetic material from two or more different sources or species

cloning

the process of producing genetically identical copies of biological material, such as genes, cells, tissues, or entire organisms

antigens

any molecule—such as a protein, sugar, or lipid—that your immune system can recognize and use to identify foreign or abnormal substances

antibodies

proteins produced by your immune system's B cells (white blood cells) to find and destroy harmful foreign substances

1st line of defense

the body’s initial, non-specific barrier system that acts immediately to prevent pathogens from entering and causing an infection

2nd line of defense

an internal, non-specific component of the innate immune system that activates immediately when pathogens breach the body's physical and chemical barriers

physical barriers

structural blocks and mechanical shields that prevent pathogens (such as bacteria, viruses, and fungi) from entering internal tissues and fluids.

chemical barriers

substances produced by the body that destroy, damage, or inhibit the growth of pathogens before they can establish an infection

microbiological barriers

the community of harmless, commensal, or mutualistic microorganisms (such as bacteria and fungi) that naturally live on and inside the human body

3rd line of defense

the adaptive (or acquired) immune response, a highly specialized, targeted defense mechanism that activates when pathogens bypass the body's first and second lines of defense

Macrophages

Large white blood cells of the innate immune system that swallow and destroy pathogens, cell debris, and cancer cells through a process called phagocytosis

Phagocytosis

a cellular process where a cell uses its plasma membrane to engulf large solid particles

neutrophils

white blood cell that kills microbes are rapidly summoned to sites of injury or infection

Natural killer cells

white blood cells that act as rapid first responders in your innate immune system, destroying virus-infected cells and early-stage cancer cells without needing prior exposure

Helper t cells

act as the "commanders" or "alarm system" of the immune response, coordinating and boosting the actions of other immune cells

cytotoxic t cells

hunt down and destroy cells in your body that have been infected with viruses, other intracellular pathogens, or have turned cancerous

How does the body distinguish self and non self antigens

all nucleated cells in the body display specialized surface proteins called MHC class I molecules that act as genetic identification tags

herd immunity

When most people are immune, the pathogen struggles to find new hosts.