Protists: The Eukaryotes That Are Not Plants, Animals or Fungi · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

The eukaryotes outside the big three

Science · Organisms & Life Processes · ages 18-19
Name ______________________   Date ____________
  1. Which trio supports endosymbiosis?

    • Green color and fast swimming
    • Own DNA, two membranes, solo division
    • Spores and hyphae
  2. Where did mitochondria come from?

    • A swallowed cell kept for energy
    • A folded cell wall
    • A captured virus
  3. Protists form one single branch of life.

    Circle one:   True   False

  4. Which pair contrasts two protist lifestyles?

    • Hunting food versus trapping sunlight
    • Flying versus burrowing
    • Seeding versus flowering
  5. Why did mitochondria join before chloroplasts?

    • Plastids carry no DNA
    • Mitochondria photosynthesise better
    • All eukaryotes keep mitochondria or traces, few keep plastids
  6. Why can protists not sit on one branch?

    • They share one recent parent cell
    • Members branch from many points of the tree
    • They hold no DNA
  7. A student says chloroplasts joined first since plants look older. What is the error?

    • Mitochondria are universal while plastids are patchy
    • Plants predate bacteria
    • Chloroplasts lack membranes
  8. Why are protists evidence FOR endosymbiosis, not an afterthought?

    • They predate every other cell
    • They disprove organelle DNA
    • They show captured partners working in varied ways
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Answer key

For grown-ups. Fold this page away before handing over the rest.

The eukaryotes outside the big three W1-mt_CHb8H727nW-s1

  1. Own DNA, two membranes, solo division · Both organelles still look and act like free bacteria.
  2. A swallowed cell kept for energy · A host kept its swallowed guest as a powerhouse.
  3. False · Protist marks a level of organisation across many branches.
  4. Hunting food versus trapping sunlight · Some engulf food while others photosynthesise, and some switch.
  5. All eukaryotes keep mitochondria or traces, few keep plastids · The universal partner must be the older joining.
  6. Members branch from many points of the tree · One branch cannot span members rooted in many places.
  7. Mitochondria are universal while plastids are patchy · Looks mislead: distribution across lines dates the joinings.
  8. They show captured partners working in varied ways · Living cells display the swallowed history still at work.
Worksheet · LightMySky