Macromolecules
Which elements make up carbohydrates and lipids?
CHO
What are the three parts of a nucleotide?
sugar, phosphate, nitrogenous base
What is the main difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells do not.
Define homeostasis.
The maintenance of a stable internal environment despite external changes.
List the levels of organization from simplest to most complex.
Cell → Tissue → Organ → Organ System → Organism.
Why is carbon called the “backbone of life”?
It can form four stable covalent bonds, creating complex molecules.
How does RNA differ from DNA (3 ways)
Single stranded, uses uracil instead of thymine, ribose sugar
What are the four main stages of mitosis?
Prophase, Metaphase, Anaphase, Telophase.
How does the cell membrane help maintain homeostasis?
By controlling what enters and leaves the cell (selective permeability).
Why is it important for organ systems to interact?
They depend on one another to perform vital functions and maintain homeostasis.
Name the four major classes of macromolecules.
Carbohydrates, Lipids, Proteins, Nucleic Acids.
What is the purpose of transcription and where does it occur?
To copy a gene from DNA into mRNA; occurs in nucleus
How does meiosis differ from mitosis?
Meiosis produces four genetically unique haploid gametes; mitosis produces two identical diploid body cells.
What is an example of a negative feedback loop in the body?
Regulation of blood glucose by insulin and glucagon.
Give one example of two systems working together to maintain homeostasis.
The respiratory and circulatory systems exchange and transport oxygen and carbon dioxide.
Match each macromolecule to its building block (monomer):
Carbohydrates → ?
Proteins → ?
Nucleic acids → ?
Lipids → ?
Monosaccharides, Amino acids, Nucleotides, Fatty acids + Glycerol.
What is the purpose of translation and where does it occur?
To use mRNA to assemble a protein; occurs on ribosomes in the cytoplasm
What process increases genetic diversity during meiosis and which phase does it occur in?
Crossing over during Prophase I.
What is an example of positive feedback in the body?
Giving birth, blood clotting
What system helps regulate blood sugar, and how does it do so?
Endocrine system; the pancreas releases insulin and glucagon.
Give an example of each macromolecule
Carbs - bread, Lipids - avocado, Protein - meat, nucleic acids - DNA/RNA
How can a mutation affect the function of a protein?
A change in the DNA base sequence may alter the amino acid sequence, changing protein shape and function
How do cells with the same DNA become specialized?
Through selective gene expression—different genes are turned on or off in different cell types.
Compare negative and positive feedback mechanisms with examples.
Negative feedback reverses a change (e.g., temperature regulation); positive feedback amplifies a change (e.g., childbirth contractions).
How does the hierarchical organization of cells and systems allow complex multicellular life to exist?
Specialized cells form tissues and organs with unique functions, allowing division of labor and efficient regulation.