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

What are the percentages of genotypes resulting from a monohybrid cross?

25% AA, 50% Aa, 25% aa.

What are the phenotype ratios resulting from a monohybrid cross?

75% dominant, 25% recessive.

What are the sex chromosomes for females and males?

Females have XX and males have XY.

What chromosome does the mother always give?

X chromosome.

What determines the sex of the baby?

The father determines the baby's sex.

What is the purpose of mitosis?

Growth and repair.

How many cells does mitosis produce?

2 identical cells.

What are the phases of mitosis?

Prophase, Metaphase, Anaphase, Telophase (PMAT).

What is the purpose of meiosis?

Makes sperm and egg.

How many different cells does meiosis produce?

4 different cells.

Define haploid and diploid.

Haploid: 23 chromosomes (gametes); Diploid: 46 chromosomes (body cells).

What are the components of an atom?

Protons (positive), Neutrons (neutral), Electrons (negative).

Define ionic bond.

Electrons are transferred between atoms.

Define covalent bond.

Electrons are shared between atoms.

What property of water allows it to be a universal solvent?

Polar covalent bonds.

What is the first step in the scientific method?

Observation.

What is the independent variable in an experiment?

Changed by the researcher.

What is a control group?

The normal group that does not receive the treatment.

List the levels of biological organization.

Atom, Molecule, Organelle, Cell, Tissue, Organ, Organ System, Organism, Population, Community, Ecosystem, Biome, Biosphere.

What are the four types of body tissues?

Epithelial, Connective, Muscle, Nervous.

What is the role of carbohydrates in the body?

Provide quick energy.

What is the main function of proteins?

Build muscles, enzymes, and repair tissues.

What are the products of cellular respiration?

ATP, Carbon Dioxide, and Water.

What does the nervous system consist of?

Brain and nerves.

What is a characteristic of bacteria?

Single-celled prokaryotes with no nucleus.

How is HIV spread?

Through blood, sex, needles, and from mother to baby.

What distinguishes an epidemic from a pandemic?

An epidemic is a large regional increase; a pandemic is worldwide spread.

What are the symptoms of malaria?

Fever, chills, and sweating.

What does AIDS indicate regarding the immune system?

The immune system is severely damaged and unable to fight infections.