Questions and Answers
What are the two types of prokaryotes--bacteria and ___?
archea
A typical bacterium consists of DNA and ___ surrounded by a cell membrane and a cell wall.
cytoplasm
Bacterial cytoplasm also contains ___.
ribosomes
Bacterial DNA occurs in one coiled, circular ___.
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A bacterium might also have smaller, circular ___ that are separate from its other DNA.
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Bacteria are much ___________ than plant or animal cells.
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Many bacteria have capsules with hairlike structures called ___.
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Bacteria generally have 1 of 3 basic shapes-- sphere, rod, or ___.
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Some bacteria take in food and break it down and obtain ___.
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The food can come from dead organisms or ___ hosts.
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___ bacteria can survive without oxygen.
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___ bacteria need oxygen, as humans do.
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Many bacteria have long whiplike structures called ___ that they use for movement.
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Bacteria reproduce asexually by ___.
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During ___, two bacteria of the same species attach to each other and combine their genetic material.
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___ is transferred between bacteria during conjugation.
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Conjugation results in new combinations of genes and increases genetic ___.
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A ___ forms when a bacterium builds a thick inner wall around its chromosome and part of the cytoplasm.
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An endospore can protect a bacterium from intense heat, cold, or _____. It can remain ____ for months or even centuries.
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Like a bacterium, a(n) ______ has a cell wall but no nucleus or membrane-bound organelles.
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The ribosomes of archaea more closely resemble the ribosomes of ___ than those of bacteria.
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Archaea often live in ___ environments, such as hot springs and salt lakes.
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Study Notes
Bacteria Overview
- Prokaryotes include two main types: bacteria and archaea.
- Bacteria possess DNA and cytoplasm within a cell membrane and cell wall.
Bacterial Structure
- Typical bacterial cytoplasm contains ribosomes essential for protein synthesis.
- Bacterial DNA is organized in one coiled, circular chromosome.
- Some bacteria may have plasmids, which are smaller, circular DNA separate from chromosomal DNA.
- Bacteria are smaller in size compared to plant and animal cells.
Bacterial Features
- Many bacteria have pili, which are hairlike structures on their capsules.
- Bacteria exhibit three basic shapes: spherical (cocci), rod-shaped (bacilli), and spiral (spirilla).
Nutrition and Energy
- Some bacteria obtain energy by breaking down food sources, which can be derived from dead organisms or living hosts.
- Aerobic bacteria require oxygen for survival, while anaerobic bacteria can thrive without it.
Movement and Reproduction
- Bacteria may possess flagella, long whiplike structures used for movement.
- Asexual reproduction in bacteria occurs through a process called fission.
- Conjugation allows two bacteria of the same species to connect and transfer genetic material, promoting genetic diversity.
Genetic Transfer and Survival
- DNA is exchanged during conjugation, leading to new genetic combinations.
- Endospores form when bacteria create a thick inner wall around their chromosome and part of the cytoplasm.
- This structural adaptation protects bacteria from extreme temperatures and drought, enabling a dormant state lasting months to centuries.
Archaea Characteristics
- Archaea share similarities with bacteria, having a cell wall but lacking a nucleus or membrane-bound organelles.
- The ribosomes of archaea closely resemble those found in eukaryotes rather than bacteria.
- Archaea thrive in extreme environments, such as hot springs and salt lakes.
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Description
Test your knowledge of bacteria and viruses with this flashcard quiz from Life Science Unit 7-1. Each card presents key terms and concepts essential to understanding prokaryotes, their structures, and functions. Perfect for reviewing before an exam!
