Biology: Q3

What are the three main points of the Cell Theory?

1. All living things are made of cells. 2) Cells come from other cells. 3) Cells are the basic structure and function of an organism.

What is a eukaryotic cell?

A cell that has a nucleus and is large and complex (e.g.

What is a prokaryotic cell?

A cell with no nucleus

What is passive transport?

• Transport of SMALL & MEDIUM materials across the plasma membrane

• REQUIRES energy (includes osmosis)

What is active transport?

• Movement of LARGE MOLECULES across the cell membrane

• REQUIRES energy (ATP)

What is osmosis?

The passive transport of water from a high to a low concentration to reach equilibrium.

What is facilitated diffusion?

• "Semi-active" transport

• Uses proteins to help move materials across the plasma membrane

• DOES NOT require energy

What is homeostasis?

The maintenance of a balanced internal condition in an organism.

What is endocytosis?

The process by which large molecules ENTER the cell.

What is exocytosis?

The process by which large molecules EXIT cell.

What is the nucleus?

The organelle in eukaryotic cells that holds DNA.

What is the function of chloroplasts?

They make glucose for the plant and are the site of photosynthesis.

What is the role of lysosomes?

They break down waste

What is the role of ribosomes?

They make proteins and are the site of translation in protein synthesis.

What is the function of the Golgi apparatus?

It sorts and packages molecules for transport within the cell.

What is the difference between smooth and rough ER?

Rough ER has ribosomes and helps in protein transport; Smooth ER does not have ribosomes and helps in lipid synthesis.

What is the role of the cell membrane?

It is semi-permeable and maintains homeostasis by controlling what enters and leaves the cell.

What is the difference between hypertonic

hypotonic

What is DNA replication?

The process of copying DNA during the S phase of interphase to ensure identical DNA in new cells.

What is transcription?

The process in which DNA is copied into a complementary strand of mRNA in the nucleus.

What is translation?

The process where mRNA is read by ribosomes to produce proteins.

What are the three types of RNA?

1. mRNA: Messenger RNA carries genetic information. 2) rRNA: Ribosomal RNA helps form ribosomes. 3) tRNA: Transfer RNA brings amino acids to ribosomes during protein synthesis.

What is a codon?

A sequence of three bases on mRNA that codes for a specific amino acid.

What is an anticodon?

A three-base complement to a codon found on tRNA.

What is a mutation?

A change in DNA sequence caused by errors in replication or exposure to mutagens.

What is selective breeding?

The process of artificially breeding organisms for a desired trait.

What is genetic drift?

A random change in the frequency of alleles in a population over time.

What is natural selection?

The process by which individuals with favorable traits survive and reproduce

What is speciation?

The formation of new species due to evolutionary changes over time.

What is a gene pool?

All the genes