BIOLOGY FINAL EXAM CRAM GUIDE CELL PARTS Cell Membrane * Controls what enters and leaves the cell. * Maintains homeostasis. Cytoplasm * Jelly-like fluid where organelles are located. Nucleus * Control center. * Contains DNA. Nucleolus * Makes ribosomes. Ribosomes * Make proteins. Rough ER * Protein production and transport. Smooth ER * Makes lipids and detoxifies chemicals. Golgi Apparatus * Packages and ships proteins. Mitochondria * Powerhouse of the cell. * Produces ATP (energy). Lysosome * Digests waste and old cell parts. Vacuole * Stores water, food, and waste. ⸻ PROKARYOTES VS EUKARYOTES Prokaryotes * No nucleus * No membrane-bound organelles * Smaller * Bacteria Eukaryotes * Has nucleus * Has organelles * Plants, animals, fungi, protists ⸻ DNA & RNA DNA Bases * A = T * C = G RNA Bases * A = U * C = G If DNA is: TAC RNA becomes: AUG AUG = Start codon (Methionine) Remember: DNA → mRNA → Protein ⸻ CODON CHART Each 3 RNA letters = 1 amino acid. Example: DNA: TAC GAA mRNA: AUG CUU Protein: Methionine – Leucine ⸻ GENE TERMS Gene * Section of DNA that codes for a trait. Genotype * Genetic makeup. * Example: AA, Aa, aa Phenotype * Physical appearance. * Example: Brown eyes ⸻ HOMOZYGOUS VS HETEROZYGOUS Homozygous Dominant AA Heterozygous Aa Homozygous Recessive aa Dominant = Capital letter Recessive = Lowercase letter ⸻ PUNNETT SQUARE Aa × Aa

Results:
25% AA
50% Aa
25% aa

Phenotype:
75% dominant
25% recessive

X AND Y CHROMOSOMES

Female
XX

Male
XY

Mother always gives:
X

Father gives:
X or Y

X + X = Girl

X + Y = Boy

Father determines baby’s sex.

Humans:
46 chromosomes
23 pairs

Egg = 23 chromosomes

Sperm = 23 chromosomes

MITOSIS

Purpose:
Growth and repair

Produces:
2 identical cells

46 → 46

Phases

PMAT

Prophase
Chromosomes condense

Metaphase
Middle

Anaphase
Separate

Telophase
Two nuclei form

MEIOSIS

Purpose
Makes sperm and egg

Produces
4 different cells

46 → 23

Result:
Haploid (23)

Mitosis:
Diploid (46)

HAPLOID VS DIPLOID

Haploid
23 chromosomes
Gametes

Diploid
46 chromosomes
Body cells

ATOMS

Atomic Number
Number of protons

Atomic Mass
Protons + neutrons

Protons
Positive

Neutrons
Neutral

Electrons
Negative

BONDS

Ionic Bond
Electrons transferred

Covalent Bond
Electrons shared

Water uses:
Polar covalent bonds

Hydrogen bonds hold water molecules together.

WATER

Properties

Universal solvent

High specific heat

Cohesion
Water sticks to water

Adhesion
Water sticks to other things

Capillary action

Transpiration
Water moves from roots to leaves then evaporates.

SCIENTIFIC METHOD

Observation

Question

Hypothesis

Experiment

Collect data

Analyze

Conclusion

EXPERIMENT TERMS

Independent Variable
Changed by researcher

Dependent Variable
Measured result

Control Group
Normal group

Experimental Group
Receives treatment

Placebo
Fake treatment

Double Blind
Neither participant nor researcher knows who gets treatment.

LEVELS OF ORGANIZATION

Atom

Molecule

Organelle

Cell

Tissue

Organ

Organ System

Organism

Population

Community

Ecosystem

Biome

Biosphere

BODY TISSUES

Epithelial
Covers surfaces

Connective
Supports body

Muscle
Movement

Nervous
Sends signals

Cardiac Muscle
Heart only

Smooth Muscle
Organs

Skeletal Muscle
Attached to bones

SKIN

Epidermis
Outer layer

Dermis
Middle layer
Blood vessels
Hair follicles
Sweat glands

Hypodermis
Fat layer

CARBOHYDRATES

Quick energy

Examples
Bread
Rice
Pasta

LIPIDS

Long-term energy

Insulation

Cell membrane

Examples
Butter
Oil

Triglyceride
3 fatty acids + glycerol

PROTEINS

Build muscles

Enzymes

Repair tissues

Made of amino acids

RESPIRATION

Cellular Respiration

Glucose + Oxygen

↓

ATP + Carbon Dioxide + Water

Occurs in mitochondria.

BODY SYSTEMS

Nervous
Brain and nerves

Circulatory
Heart and blood

Respiratory
Lungs

Digestive
Breaks food down

Muscular
Movement

Skeletal
Support

Endocrine
Hormones

Immune
Fights infection

Urinary
Removes waste

Reproductive
Produces offspring

Integumentary
Skin

BACTERIA

Single-celled

Prokaryote

No nucleus

Can be helpful or harmful

Reproduce by binary fission

HIV

Virus

Attacks helper T cells (CD4)

Weakens immune system

Can lead to AIDS if untreated

Spread by:
Blood
Sex
Needles
Mother to baby

AIDS

Final stage of HIV

Immune system severely damaged

Body can’t fight infections

COVID-19

Virus

Spread by respiratory droplets

Symptoms:
Fever
Cough
Fatigue
Loss of taste/smell

MALARIA

Caused by parasite

Spread by mosquito bites

Symptoms:
Fever
Chills
Sweating

INFECTIOUS DISEASES

Caused by:
Bacteria

Viruses

Fungi

Parasites

Spread through:
Air
Water
Food
Blood
Contact

EPIDEMIC VS PANDEMIC

Outbreak
Small/local increase

Epidemic
Large regional increase

Pandemic
Worldwide spread

CHROMOSOME FACTS

Body cells
46 chromosomes

Gametes
23 chromosomes

23 pairs

1 pair determines sex

XX = Female

XY = Male