prokaryotic and eukaryotic cells
Prokaryotic cells ( Figure 1.2) are usually smaller and simpler than eukaryotic cells. They do not have a nucleus or other membrane-bound organelles. In prokaryotic cells, the DNA, or genetic material, forms a single large circle that coils up on itself. The DNA is located in the main part of the cell. Nucleus DNA Membrane-Bound Organelles Examples Prokaryotic Cells No Single circular piece of DNA No Bacteria Eukaryotic Cells Yes Multiple chromosomes Yes Plants, animals, fungi
Eukaryotic cells usually have multiple chromosomes, composed of DNA and protein. Some eukaryotic species have just a few chromosomes, others have close to 100 or more. These chromosomes are protected within the nucleus. In addition to a nucleus, eukaryotic cells include other membrane-bound structures called organelles. Organelles allow eukaryotic cells to be more specialized than prokaryotic cells. Pictured below are the organelles of eukaryotic cells ( Figure 1.1), including the mitochondria, endoplasmic reticulum, and Golgi apparatus. These will be discussed in additional concepts. DNA (chromatin) is stored. Organelles give eukaryotic cells more functions than prokaryotic cells.
prokaryotic and eukaryotic
There are two basic types of cells, prokaryotic cells and eukaryotic cells. The main difference between eukaryotic and prokaryotic cells is that eukaryotic cells have a nucleus. The nucleus is where cells store their DNA, which is the genetic material. The nucleus is surrounded by a membrane. Prokaryotic cells do not have a nucleus. Instead, their DNA floats around inside the cell. Organisms with prokaryotic cells are called prokaryotes. All prokaryotes are single-celled (unicellular) organisms. Bacteria and Archaea are the only prokaryotes. Organisms with eukaryotic cells are called eukaryotes. Animals, plants, fungi, and protists are eukaryotes. All multicellular organisms are eukaryotes. Eukaryotes may also be single-celled. Both prokaryotic and eukaryotic cells have structures in common. All cells have a plasma membrane, ribosomes, cytoplasm, and DNA. The plasma membrane, or cell membrane, is the phospholipid layer that surrounds the cell and protects it from the outside environment. Ribosomes are the non-membrane bound organelles where proteins are made, a process called protein synthesis. The cytoplasm is all the contents of the cell inside the cell membrane, not including the nucleus.
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all prokaryotes are single-celled organisms.
--> a. true b. false
eukaryotes may be single-celled or multicellular organisms.
--> a. true b. false
all cells have a ______
a) plasma membrane, ribosomes, endoplasmic reticulum and mitochondria. b) mitochondria, endoplasmic reticulum and golgi apparatus. --> c) plasma membrane, ribosomes, cytoplasm and dna. d) mitochondria, endoplasmic reticulum, cytoplasm and dna.
which of the following are made of eukaryotic cells?
--> a) animals, plants and fungi b) archaea, protists and fungi c) bacteria, archaea and protists d) animals, plants and archaea
what is the cell structure where energy is generated?
a) ribosome --> b) mitochondria c) endoplasmic reticulum d) golgi apparatus
which organelle is the site of protein synthesis?
a) the endoplasmic reticulum b) the mitochondria c) the cytoplasm --> d) the ribosome
chromosomes are protected by the ____.
a) plasma membrane --> b) nucleus c) cytoplasm d) ribosomes
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