Chapter 27 Diversification of Eukaryotes (Protist Divesirty)

BIO

What is the main difference between mitosis and meiosis?

Mitosis produces 2 identical diploid daughter cells

Meiosis produces 4 non-identical haploid daughter cells.

How many daughter cells are produced in mitosis vs meiosis?

Mitosis: 2 diploid cells

Meiosis: 4 haploid cells.

Are mitotic daughter cells genetically identical to the parent cell?

Yes, mitotic cells are genetically identical to the parent.

Are meiotic daughter cells genetically identical to each other or the parent?

No, they are genetically unique due to crossing over and independent assortment.

When did eukaryotes evolve from Archaea?

Approximately 2.1 billion years ago

What is endosymbiosis?

A process where a cell engulfs another cell that lives inside it and becomes an organelle.

What is the origin of mitochondria?

Engulfed aerobic heterotrophic bacteria; provides ATP to host cell.

What is the origin of chloroplasts?

Engulfed cyanobacteria; found in plant and plant-like protist cells.

What are some characteristics of eukaryotic cells?

Membrane-bound organelles (e.g., nucleus, mitochondria), linear chromosomes.

What is the evidence for endosymbiosis?

Organelle size ~ prokaryotes, circular DNA, complex membranes, binary fission

What are protists?

Eukaryotic, mostly unicellular organisms that live in moist environments.

What’s the difference between colonial and multicellular organisms?

Colonial: cells live together but function independently; Multicellular: cells are specialized and dependent.

Why are protists considered paraphyletic?

They don't all descend from a single common ancestor.

Describe protist nutritional diversity.

Animal-like (ingest), plant-like (photosynthesize), fungi-like (absorb); can be parasitic, symbiotic, or free-living

How do protists reproduce?

Asexually or sexually. Sexual = genetic diversity; Asexual = fast, no mate needed.

Why is sexual reproduction beneficial in protists?

Increases genetic variation and helps escape poor environmental conditions.

What are the advantages of asexual reproduction?

No partner needed; maintains traits suited for stable environments.

Why are protists important?

Produce ~50% of atmospheric O₂, base of food chains, water filtration, cause diseases.

Give examples of important protists.

Malaria (Plasmodium), slime mold, dinoflagellates, choanoflagellates.

How do protists move?

Using cilia, flagella, or pseudopodia.