3 Domains of Life

Question 1

Cell Theory

Answer 1

describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction. … Cell theory was eventually formulated in 1839. This is usually credited to Matthias Schleiden and Theodor Schwann.

Question 2

Plasma membrane

Answer 2

the boundary between the cell and its environment. It regulates what enters and exits the cell. Cells must maintain an appropriate amount of molecules to function inside them.

Question 3

Cytosol

Answer 3

In the eukaryotic cell, the cytosol is within the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles.

Question 4

Cytoplasm

Answer 4

the material or protoplasm within a living cell, excluding the nucleus.

Question 5

Organelles

Answer 5

found only in eukaryotic cells and are absent from the cells of prokaryotes such as bacteria. The nucleus, the mitochondrion, the chloroplast, the Golgi apparatus, the lysosome, and the endoplasmic reticulum are all examples

Question 6

Cytoskeleton

Answer 6

network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.

Question 7

Prokaryotes

Answer 7

single-celled organism that lacks a membrane-bound nucleus (karyon), mitochondria, or any other membrane-bound organelle.. Prokaryotes can be divided into two domains, Archaea and Bacteria.

Question 8

Eukaryotes

Answer 8

contain other membrane-bound organelles such as mitochondria and the Golgi apparatus. In addition, plants and algae contain chloroplasts. Eukaryotic organisms may be unicellular or multicellular.

Question 9

Nucleus

Answer 9

central and most important part of an object, movement, or group, forming the basis for its activity and growth.

Question 10

Cell Wall

Answer 10

a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants, it consists mainly of cellulose.

Question 11

Nuclear Envelope

Answer 11

the phospholipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells.

Question 12

Chromatin

Answer 12

the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.

Question 13

Chromosome

Answer 13

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Question 14

Nucleoli

Answer 14

a small dense spherical structure in the nucleus of a cell during interphase.

Question 15

Bacteria

Answer 15

icroscopic living organisms, usually one-celled, that can be found everywhere. They can be dangerous, such as when they cause infection, or beneficial, as in the process of fermentation

Question 16

Archaea

Answer 16

Single-celled microorganisms. These microbes are prokaryotes, meaning that they have no cell nucleus or any other membrane-bound organelles in their cells. Wikipedia

Question 17

Virus

Answer 17

infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.

Question 18

How can you tell a eukaryotic cell apart from a prokaryotic cell?

Answer 18

The prokaryotes - are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. They differ from the eukaryotes, which have a cell nucleus. Most are unicellular, but a few prokaryotes such as myxobacteria have multicellular stages in their life cycles.

A eukaryote - is an organism whose cells contain complex structures enclosed within membranes. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried.

eukaryotic cells lack a nucleus and are smaller and simpler than eukaryotic. 3. Eukaryotic cells are much larger than prokaryotic cells, and therefore have less surface area per volume. Eukaryotic cells have a nucleus and organelles. .A membrane bounded nucleus houses DNA.
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Question 19

What are the main differences between Archaea and Bacteria?

Answer 19

Unlike bacteria, archaea cell walls do not contain peptidoglycan. Archaea have different membrane lipid bonding compared to Bacteria and Eucarya. Archaeal lipids lack the fatty acids found in Bacteria and Eukaryotes and instead have side chains composed of repeating units of isoprene.

Question 20

How do organelles and cytoskeletal systems allow eukaryotic cells to be much bigger than
prokaryotic cells?

Answer 20

Prokaryotic cells have no nuclei, while eukaryotic cells do have true nuclei.
Eukaryotic DNA is linear; prokaryotic DNA is circular (it has no ends).

Question 21

Describe the structure of a virus.

Answer 21

Picture?

Question 22

Why aren’t viruses considered living organisms?

Answer 22

lack many of the properties that scientists associate with living organisms. Primarily, they lack the ability to reproduce without the aid of a host cell, and don’t use the typical cell- division approach to replication.