Name: antibiotic resistance in cloning
Uploaded: 2026-08-26T08:20:54.022Z
Duration: 1 min 45 s
Channel: JoVE

K12 Standards

Louisiana Student Standards for Science

High School

Life Sciences

from-molecules-to-organisms-structures-and-processes

From Molecules To Organisms: Structures And Processes

HS-LS1-8

Antibiotic Selection

- La s&#xE9;lection d&#x27;un antibiotique est g&#xE9;n&#xE9;ralement utilis&#xE9;epour s&#x27;assurer qu&#x27;une colonie bact&#xE9;riennecontient un plasmide pr&#xE9;sentant certaines caract&#xE9;ristiques :un g&#xE8;ne de r&#xE9;sistance &#xE0; l&#x27;antibiotique,et un g&#xE8;ne int&#xE9;ressant qu&#x27;un&#xB7;e chercheur&#xB7;euse veut exprimer. 
Pour que la bact&#xE9;rie assimile le plasmide,tous deux doivent &#xEA;tre incub&#xE9;s ensemble,puis subir un choc thermique pour favoriser l&#x27;incorporation. 
Toutes les bact&#xE9;ries n&#x27;arriveront pas &#xE0; assimilerune copie d&#x27;un plasmide. 
Le but est d&#x27;isoler les bact&#xE9;ries qui poss&#xE8;dent une copie,donc les chercheur&#xB7;euses ajoutent un peu de cette culture&#xE0; une bo&#xEE;te de Petri contenant un antibiotique. 
Seules les bact&#xE9;ries qui ont assimil&#xE9; le plasmidecontenant le g&#xE8;ne de r&#xE9;sistancevont pouvoir d&#xE9;grader l&#x27;antibiotiqueet se multiplier dans la bo&#xEE;te de Petri. 
Dans les jours qui suivent,des bact&#xE9;ries seules vont former des colonies,qui peuvent ensuite &#xEA;tre s&#xE9;lectionn&#xE9;espour d&#x27;autres exp&#xE9;riences.

Courvalin, P. 2016. « Pourquoi la résistance aux antibiotiques est-elle une maladie émergente mortelle ? », Microbiologie clinique et infection 22 (5) : 405-7. [<a href="https://doi.org/10.1016/j.cmi.2016.01.012 » target="__blank">Source</a>]

Daubin, Vincent et Gergely J. Szöllősi. 2016. « Le transfert horizontal de gènes et l’histoire de la vie », Cold Spring Harbor : Perspectives en biologie 8 (4). [<a href="https://doi.org/10.1101/cshperspect.a018036 » target="__blank">Source</a>]

Hiltunen, Teppo, Marko Virta et Anna-Liisa Laine. 2017. « Résistance aux antibiotiques dans la nature : une perspective éco-évolutive ». Transactions philosophiques de la Royal Society B : Sciences biologiques 372 (1712). [<a href="https://doi.org/10.1098/rstb.2016.0039 » target="__blank">Source</a>]

sélection avec un antibiotique

<h4>Aper&#xE7;u</h4>
 
 Les chercheurs utilisent des g&#xE8;nes de r&#xE9;sistance aux antibiotiques pour identifier les bact&#xE9;ries qui poss&#xE8;dent un plasmide contenant leur g&#xE8;ne d&#x2019;int&#xE9;r&#xEA;t. La r&#xE9;sistance aux antibiotiques se produit naturellement lorsqu&#x2019;une mutation spontan&#xE9;e de l&#x2019;ADN cr&#xE9;e des modifications dans les g&#xE8;nes bact&#xE9;riens qui suppriment l&#x2019;activit&#xE9; de l&#x2019;antibiotique. Les bact&#xE9;ries peuvent partager ces nouveaux g&#xE8;nes de r&#xE9;sistance avec leur prog&#xE9;niture et d&#x2019;autres bact&#xE9;ries. L&#x2019;utilisation excessive et abusive d&#x2019;antibiotiques a cr&#xE9;&#xE9; une crise de sant&#xE9; publique, alors que les bact&#xE9;ries r&#xE9;sistantes et multir&#xE9;sistantes continuent de se d&#xE9;velopper.
 
 <h4>La r&#xE9;sistance aux antibiotiques est un outil essentiel du g&#xE9;nie g&#xE9;n&#xE9;tique</h4>
 
 Les antibiotiques, comme la p&#xE9;nicilline, sont des m&#xE9;dicaments qui tuent ou arr&#xEA;tent la croissance bact&#xE9;rienne. Les bact&#xE9;ries qui ont acquis naturellement ou artificiellement des g&#xE8;nes de r&#xE9;sistance aux antibiotiques ne r&#xE9;agissent pas aux antibiotiques. Les scientifiques exploitent cela en concevant des plasmides &#x2014; de petits morceaux d&#x2019;ADN se r&#xE9;pliquant eux-m&#xEA;me &#x2014; qui portent &#xE0; la fois un g&#xE8;ne de r&#xE9;sistance aux antibiotiques et un g&#xE8;ne d&#x2019;int&#xE9;r&#xEA;t. La r&#xE9;sistance aux antibiotiques fait partie int&#xE9;grante du clonage d&#x2019;ADN en permettant &#xE0; un chercheur d&#x2019;identifier les cellules qui ont absorb&#xE9; un ADN d&#x2019;int&#xE9;r&#xEA;t.
 
 L&#x2019;ADN d&#x2019;int&#xE9;r&#xEA;t du chercheur est introduit dans les cellules bact&#xE9;riennes &#xE0; l&#x2019;aide d&#x2019;un processus appel&#xE9; transformation. La transformation bact&#xE9;rienne consiste &#xE0; cr&#xE9;er temporairement de petits trous dans la paroi cellulaire bact&#xE9;rienne pour permettre la p&#xE9;n&#xE9;tration d&#x2019;ADN externe comme un plasmide. Seules quelques cellules bact&#xE9;riennes absorbent le nouvel ADN. &#xC9;tant donn&#xE9; que le plasmide comprend &#xE0; la fois l&#x2019;ADN d&#x2019;int&#xE9;r&#xEA;t et un g&#xE8;ne qui conf&#xE8;re une r&#xE9;sistance &#xE0; un antibiotique sp&#xE9;cifique, l&#x2019;application de l&#x2019;antibiotique aux cellules bact&#xE9;riennes (c.-&#xE0;-d. la s&#xE9;lection par antibiotique) peut aider &#xE0; d&#xE9;terminer quelles cellules ont &#xE9;t&#xE9; g&#xE9;n&#xE9;tiquement modifi&#xE9;es.
 
 Le chercheur r&#xE9;pand les cellules bact&#xE9;riennes sur une boite de culture contenant un antibiotique choisi. Seules les bact&#xE9;ries contenant le g&#xE8;ne de r&#xE9;sistance &#xE0; l&#x2019;antibiotique survivent et se d&#xE9;veloppent dans la boite. Au bout de quelques jours, le chercheur peut s&#xE9;lectionner une colonie bact&#xE9;rienne pour la cultiver dans d&#x2019;autres exp&#xE9;riences, telles que l&#x2019;&#xE9;tude de l&#x2019;expression des g&#xE8;nes. Apr&#xE8;s la s&#xE9;lection par un antibiotique, le chercheur effectuera d&#x27;autres tests sur les bact&#xE9;ries en utilisant d&#x27;autres m&#xE9;thodes (par exemple, la PCR) pour confirmer que l&#x27;ADN d&#x27;int&#xE9;r&#xEA;t est correct. Des erreurs se produisent souvent, comme le plasmide qui ne contient pas du tout le g&#xE8;ne d&#x2019;int&#xE9;r&#xEA;t.
 
 <h4>Les bact&#xE9;ries peuvent acqu&#xE9;rir une r&#xE9;sistance aux antibiotiques naturellement</h4>
 
 Les bact&#xE9;ries peuvent acqu&#xE9;rir une r&#xE9;sistance aux antibiotiques gr&#xE2;ce &#xE0; des mutations spontan&#xE9;es de l&#x2019;ADN qui modifient les prot&#xE9;ines produites par la cellule. Les bact&#xE9;ries r&#xE9;sistantes peuvent produire des prot&#xE9;ines qui font que l&#x2019;antibiotique est soit d&#xE9;grad&#xE9; soit pomp&#xE9; hors de la cellule, ou qui l&#x2019;emp&#xEA;chent d&#x2019;interagir avec sa cible. Par exemple, l&#x2019;antibiotique vancomycine inhibe la synth&#xE8;se de la paroi cellulaire bact&#xE9;rienne. Certaines bact&#xE9;ries ont d&#xE9;velopp&#xE9; une r&#xE9;sistance &#xE0; cet antibiotique en rempla&#xE7;ant les types de sous-unit&#xE9;s prot&#xE9;iques &#x2014; acides amin&#xE9;s &#x2014; qui sont utilis&#xE9;s dans l&#x27;assemblage de leur paroi cellulaire par d&#x2019;autres qui ne sont pas impact&#xE9;s par la vancomycine.
 
 Une fois que les g&#xE8;nes de r&#xE9;sistance aux antibiotiques &#xE9;mergent, les bact&#xE9;ries peuvent les transmettre &#xE0; leur prog&#xE9;niture. Les bact&#xE9;ries peuvent &#xE9;galement acqu&#xE9;rir des g&#xE8;nes de r&#xE9;sistance aux antibiotiques &#xE0; partir d&#x2019;autres bact&#xE9;ries de la m&#xEA;me esp&#xE8;ce ou d&#x2019;une esp&#xE8;ce diff&#xE9;rente gr&#xE2;ce &#xE0; un processus appel&#xE9; transfert horizontal de g&#xE8;nes (HGT). Il existe trois m&#xE9;canismes de HGT : la transformation, la conjugaison et la transduction. Les g&#xE8;nes de r&#xE9;sistance aux antibiotiques sont souvent pr&#xE9;sents dans les plasmides ou les transposons &#x2014; des morceaux d&#x2019;ADN facilement transf&#xE9;r&#xE9;s entre les bact&#xE9;ries &#x2014; qui sont &#xE9;chang&#xE9;s pendant le HGT. En cons&#xE9;quence, de nouveaux types de r&#xE9;sistance aux antibiotiques peuvent rapidement se propager &#xE0; de multiples sortes de bact&#xE9;ries infectieuses.
 
 <h4>L&#x2019;utilisation clinique excessive et l&#x2019;abus d&#x2019;antibiotiques produisent des &#x201C; superbact&#xE9;ries &#x201D;</h4>
 
 Les antibiotiques sont un traitement essentiel contre les infections bact&#xE9;riennes. Cependant, leur utilisation peut rendre les bact&#xE9;ries r&#xE9;sistantes et rendre l&#x2019;antibiotique inefficace, conduisant &#xE0; des infections incurables et potentiellement mortelles. La surconsommation et l&#x2019;abus d&#x2019;antibiotiques &#x2014; par exemple, l&#x2019;utilisation d&#x2019;antibiotiques pour traiter les infections virales (plut&#xF4;t que bact&#xE9;riennes) ou pour accro&#xEE;tre la croissance du b&#xE9;tail &#x2014; est probl&#xE9;matique parce que cela favorise la r&#xE9;sistance.
 
 Les antibiotiques provoquent l&#x2019;&#xE9;volution de la r&#xE9;sistance parce qu&#x2019;ils tuent les bact&#xE9;ries sensibles et ne laissent que les individus r&#xE9;sistants. Les bact&#xE9;ries survivantes se divisent rapidement, produisant une prog&#xE9;niture avec la m&#xEA;me r&#xE9;sistance aux antibiotiques. Lorsque les antibiotiques sont utilis&#xE9;s de fa&#xE7;on abusive, cette pression de s&#xE9;lection entra&#xEE;ne une augmentation rapide du nombre de bact&#xE9;ries r&#xE9;sistantes dans la population. Il s&#x2019;agit d&#x2019;un probl&#xE8;me majeur de sant&#xE9; publique parce qu&#x2019;il augmente la r&#xE9;sistance aux antibiotiques et cr&#xE9;e des &#x201C; superbact&#xE9;ries &#x201D; r&#xE9;sistantes &#xE0; de multiples antibiotiques. Une utilisation excessive et abusive prolong&#xE9;e des antibiotiques pourrait finalement &#xE9;puiser les options de traitement contre les infections bact&#xE9;riennes.

Sélection avec un antibiotique

Overview

Researchers use antibiotic resistance genes to identify bacteria that possess a plasmid containing their gene of interest. Antibiotic resistance ...

https://cloudfront.jove.com/files/ftp_upload/10807/10807_article_thumb_10807.jpg

Education

Enseignement

JoVE Core

Biology

Biologie

Genetics

Génétique

Biotechnology

Biotechnologie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

antibiotic resistance in cloning

Antibiotic resistance genes help scientists find bacteria that took up a plasmid with a gene of interest. In genetic engineering, this resistance is used as a marker, not just as a medical concern. The same process also connects to the growing problem of resistant bacteria in the real world.

Antibiotics, such as penicillin, stop bacterial growth or kill bacteria. When bacteria naturally have, or are engineered to carry, an antibiotic resistance gene, the antibiotic no longer works on them. Researchers build plasmids, which are small pieces of self-replicating DNA, with both the gene of interest and a resistance gene. This makes antibiotic resistance an important part of DNA cloning and cell selection.

To move DNA into bacteria, scientists use transformation. During transformation, small holes are made in the bacterial cell wall so external DNA, like a plasmid, can enter. Only some cells take up the new DNA. Scientists then place the bacteria on a plate containing the chosen antibiotic. Only cells with the resistance gene survive and form colonies.

After a few days, a colony can be picked and grown for later experiments, such as gene expression studies. The bacteria are often tested again with methods like PCR to confirm that the DNA of interest is correct. This step matters because mistakes can happen, including plasmids that do not contain the target gene at all.

Bacteria can also gain antibiotic resistance naturally through spontaneous DNA mutations. These changes may produce proteins that break down the antibiotic, pump it out of the cell, or block it from reaching its target. For example, vancomycin blocks bacterial cell wall synthesis, but some bacteria avoid its effect by changing the amino acid subunits used to build their cell wall.

Once resistance genes appear, bacteria can pass them to offspring. They can also share them with other bacteria through horizontal gene transfer, or HGT. The three main HGT methods are transformation, conjugation, and transduction. Resistance genes are often carried on plasmids or transposons, which can move easily between cells and spread new resistance traits quickly.

Antibiotic overuse and misuse have made this problem worse. Using antibiotics for viral infections or to increase livestock growth can select for resistant bacteria. The susceptible bacteria die, while resistant survivors keep dividing and passing on the same trait. Over time, this can lead to multi-resistant bacteria, or superbugs, and may leave fewer treatment options for bacterial infections.

Antibiotic Resistance in Cloning

what is genetic engineering?

How Scientists Edit DNA for New Traits

Genetic engineering changes an organism’s DNA to add useful traits. Scientists use it in bacteria, plants, animals, and even viruses for research, medicine, agriculture, and industry. It can bring major benefits, but it also raises ethical concerns about humans and the food supply. This work is possible because DNA has the same basic structure and genetic code across life. That shared code lets scientists modify DNA in several ways. One method is CRISPR/Cas9, often called molecular scissors,...

dna isolation

Steps in DNA Extraction

DNA extraction is the process of removing and purifying DNA from cells. It is used in many biotechnology and research applications, including molecular cloning. The main goal is to free DNA from the cell and prepare it for later study or use. The first step is cell lysis, which means breaking cells open. Researchers may use a homogenizer, sonicator, or bead beater to physically lyse the cells. They also often add detergent to chemically disrupt the lipid-based cell membranes. This helps...

recombinant dna technology

Recombinant DNA in Cloning and GMOs

Recombinant DNA is made by joining DNA from different sources in the lab. Scientists often use it to clone genes and study them in cells that are easy to handle, such as bacteria. Organisms that carry recombinant DNA are called genetically modified organisms, or GMOs. This technology gives scientists new tools for research, medicine, and agriculture. To build recombinant DNA, researchers place a gene of interest into a vector, which is a DNA carrier that moves foreign DNA into a host cell. The...

PCR Cycle for DNA Amplification

PCR is a laboratory method for making many copies of a DNA segment. It can turn a small amount of DNA into millions or even billions of copies in just a few hours. The process uses a heat-resistant DNA polymerase inside a machine called a thermocycler. PCR was developed by Kary Mullis in 1983, and he received the 1993 Nobel Prize in Chemistry for it. The method is fast, relatively inexpensive, and precise. It has become useful for molecular cloning, gene mutagenesis, pathogen detection, gene...

complementary dna

From mRNA to cDNA for Gene Studies

Complementary DNA, or cDNA, is made from messenger RNA (mRNA) so scientists can study which genes are active in cells and tissues. Only genes that are transcribed into mRNA are expressed. By extracting mRNA from cells, researchers can compare gene expression across samples. cDNA is produced by reverse transcription. This process copies mRNA into DNA, which is useful because mRNA does not contain introns, or non-coding regions, and other regulatory sequences. As a result, cDNA can help...

antibiotic selection

Antibiotic resistance genes help scientists find bacteria that took up a plasmid with a gene of interest. In genetic engineering, this resistance is used as a marker, not just as a medical concern. The same process also connects to the growing problem of resistant bacteria in the real world. Antibiotics, such as penicillin, stop bacterial growth or kill bacteria. When bacteria naturally have, or are engineered to carry, an antibiotic resistance gene, the antibiotic no longer works on them.

transgenic organisms

Creating Transgenic Plants and Animals

Transgenic organisms are genetically engineered to carry a transgene, which is a gene from a different species, in their genome. The inserted gene may be a new gene for that organism or a different version of one it already has. Scientists usually make transgenes with recombinant DNA and DNA cloning methods. Researchers use transgenic bacteria, plants, and animals to answer biological questions and to build useful tools. To make a transgenic organism, they first choose a transgenesis method,...

in-vitro mutagenesis (gene knockouts)

Knockout Mice and Gene Replacement

Knockout mice help researchers study gene function by showing what happens when a gene is turned off. These engineered animals are also useful for modeling human diseases such as cancer, Parkinson’s disease, and diabetes. A specific gene can be targeted by using a targeting vector, which is a piece of engineered DNA that replaces the normal gene and inactivates it. The vector has matching DNA sequences on both ends. These homologous sequences let the vector swap in for the target gene through...

crispr

CRISPR-Cas9 Gene Editing in Action

CRISPR-Cas9 is a genome editing tool that lets scientists change DNA at a specific location. It can add, remove, or rearrange genetic material. Researchers study it because it may help treat genetic disorders such as hemophilia and sickle cell anemia. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, and Cas9 is a CRISPR-associated protein 9. The basic system includes a Cas9 endonuclease, which is an enzyme that cuts DNA, and a small RNA that guides Cas9 to the...

gene therapy

Gene Delivery for Serious Diseases

Gene therapy is a technique used to treat serious disease by adding a gene to a person’s cells. The added gene may be a healthy copy of a mutated gene. It may also be a different gene that inactivates or compensates for the disease-causing gene. One example is severe combined immunodeficiency, or SCID, caused by a mutation in the gene for adenosine deaminase. In that case, a working copy of the gene can be inserted so the patient’s cells make the enzyme again. This can cure the disease in some...

embryonic stem cells

How Embryonic Stem Cells Become Specialized

Embryonic stem cells are pluripotent cells that have not yet specialized. Pluripotent means they can give rise to many different cell types in the body. Because of this, they are useful in science and medicine for making cells needed in research or for replacing cells lost to damage or disease. These cells come from the inner cell mass of a blastocyst, which is an early embryo about 3 to 5 days after fertilization in humans. At this stage, the embryo has not yet implanted in the uterus. Human...

adult stem cells

Adult Stem Cells in the Small Intestine

Adult stem cells help maintain tissues by replacing old or damaged cells. These undifferentiated cells divide to make more stem cells or progenitor cells, which then become mature, specialized cells. Small groups of adult stem cells are found in many tissues, including the bone marrow, brain, skin, and gut. The small intestine shows this process clearly. Its lining, called the epithelium, is renewed continuously by adult stem cells. It is also the fastest replaced tissue in the human body,...

induced pluripotent stem cells

Reprogramming Mature Cells into Stem Cells

Reprogramming mature cells into stem cells lets scientists turn specialized cells back into an unspecialized state. These cells are called induced pluripotent stem cells, or iPSCs. Like embryonic stem cells, iPSCs are pluripotent, which means they can form all cell types. To make iPSCs, researchers start with mature cells such as skin fibroblasts or blood cells. The cells are grown in culture, and genes for several transcription factors are delivered with a viral vector. The cells then make...

reproductive cloning

Cloning Animals with SCNT

Reproductive cloning can produce a genetically identical copy of an entire organism. In adult animals, this is usually done with somatic cell nuclear transfer, or SCNT. Another way clones can form is by splitting an early embryo, which is similar to how identical twins arise naturally. In SCNT, an egg cell is taken from an animal and its nucleus is removed. This creates an enucleated egg. A somatic cell, which is any body cell that is not a sex cell, is then taken from the animal to be cloned.

genomics

Genomics and DNA Sequencing

Genomics studies the full set of genetic material in an organism. In humans, that genome includes the DNA carried in 23 pairs of chromosomes in the nucleus, along with mitochondrial DNA. Genomics looks at both coding DNA and non-coding DNA, which helps scientists study how living things are built and how they differ. This field is useful in many areas of biology and medicine. Scientists use genomics to build phylogenetic trees, improve crop productivity and sustainability, help with criminal...

key terms and concepts

Learn how antibiotic resistance genes help scientists select transformed bacteria, and why resistance and superbugs are a major health concern.

Antibiotic Resistance in Cloning | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

La collection JoVE Core Biologie donne vie à la biologie à travers plus de 300 leçons vidéos animées concises et faciles à comprendre qui expliquent les concept clés de la biologie, mais aussi plus de 150 vidéos de scientifiques à l'action effectuant des expériences de recherche dans des laboratoires modernes.

Georgia Standards of Excellence

9-12

SB6.e

Nucleic Acids and Nucleotides

Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell&#39;s genetic blueprint and have instructions for its ...

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group ...

DNA Base Pairing

Erwin Chargaff&#x2019;s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff&#x2019;s rules state that in a ...

From DNA to Protein

The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of ...

The DNA Helix

Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA ...

The Central Dogma

The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins.
RNA is the Missing Link Between ...

Genomic DNA in Prokaryotes

The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the ...

Genomic DNA in Eukaryotes

Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the ...

Overview

Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most ...

DNA Packaging

Overview

Eukaryotes have large genomes compared to prokaryotes. In order to fit their genomes into a cell, eukaryotes must pack their DNA tightly inside ...

RNA Structure

Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form ...

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations ...

pre-mRNA Processing

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or ...

Types of RNA

Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs ...

DNA as a Genetic Template

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Translation

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

tRNA Activation

Initiation of Translation

Termination of Translation

What are Cells?

Cell Diversity

The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term &#34;cell&#34; based on the ...

Cells of the Epidermis

The epidermis is made of four or five layers of epithelial cells, depending on its location in the body. From deep to superficial, these layers are the ...

Bone Cells and Tissue

Bones contain a relatively small number of cells entrenched in a matrix of organic and inorganic components. Although bone cells compose only a small ...

Gross Anatomy of Skeletal Muscles

The connective tissues play a significant role in arranging the muscle fibers into a hierarchical structure that forms a complete muscle. Consider a ...

Structure of Cardiac Muscles

Cardiac muscle, or myocardium, is a specialized type of muscle found exclusively in the heart. Its unique structural and functional characteristics enable ...

structure-and-organization-of-smooth-muscles

Structure and Organization of Smooth Muscles

In the human body, smooth muscle tissue is found lining the visceral and tubular organs such as the liver, lungs, blood vessels, and respiratory tract.
...

Chromosome Replication

Before a cell can divide, it must accurately replicate all of its chromosomes, including the DNA and its associated histone and non-histone ...

Neurons: The Cell Body and the Dendrites

A typical nerve cell comprises three main components: the cell body, dendrites, and the axon. The cell body, also known as the soma or perikaryon, serves ...

Lampbrush Chromosomes

In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, R&#252;ckert observed LBCs in shark egg cells and coined the ...

Neurons: The Axon

The axon is a long, thin extended portion of the neuron that carries impulses from its cell body toward the effector cell.
Axoplasm, the axon&#39;s ...

Polytene Chromosomes

Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in ...

Nervous Tissue: Neuron Types

Neurons, the fundamental units of the nervous system, can be classified based on both their structural and functional characteristics.
Structurally, ...

Euchromatin

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions ...

Nervous Tissue: Glial Cells

Glial cells or neuroglia are non-neuronal cells in the nervous system that outnumber neurons. These include astrocytes, oligodendrocytes, microglia, and ...

Heterochromatin

Lymphoid Cells and Tissues

Lymphoid cells and lymphoid tissues are the two major components of lymphoid organs.
Lymphoid cells consist of immune system cells such as B and T ...

chromatin-position-affects-gene-expression

Chromatin Position Affects Gene Expression

Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the ...

Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The ...

Organization of Genes

Chromosome Structure

A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication.
The centromere is a DNA ...

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells. Emphasis is on the conceptual understanding that DNA sequences determine the amino acid sequence and thus protein structure. Students can produce scientific writing, or presentations, and/or physical models that communicate constructed explanations.

HS-LS1-1

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

Levels of Organization

Biological organization is the classification of biological structures, ranging from atoms at the bottom of the hierarchy to the Earth&#x27;s biosphere. ...

The Scientific Method

The scientific method is a detailed, empirical problem-solving process used by biologists and other scientists. This iterative approach involves ...

Taxonomy

Taxonomy is the science of defining and naming groups of biological organisms based on shared characteristics. It uses a hierarchy of increasingly ...

Phylogeny

Phylogeny is concerned with the evolutionary diversification of organisms or groups of organisms. A group of organisms with a name is called a taxon ...

Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. Emphasis is on functions at the organism system level such as nutrient uptake, water delivery, or organism movement in response to neural stimuli. An example of an interacting system could be an artery depending on the proper function of elastic tissue and smooth muscle to regulate and deliver the proper amount of blood within the circulatory system.

HS-LS1-2

Overview of Metabolism

Living cells constantly carry out various chemical reactions which are necessary for their proper functioning. These reactions are interlinked to one ...

Regulation of Metabolism

Cellular needs and conditions vary from cell to cell and change within individual cells over time. For example, the required enzymes and energetic demands ...

Positive and Negative Feedback Loops

Animal organs and organ systems constantly adjust to internal and external changes through a process called homeostasis (&#34;steady state&#34;). Examples ...

Functions of Life

Human life is characterized by a variety of functions that are essential for survival and well-being. These functions include metabolism, movement, ...

Requirements for Human Life

The Earth and its atmosphere have provided humans with air, water, and food, but these are not the only requirements for survival. Humans also require a ...

What is Homeostasis?

Maintaining homeostasis requires that the body continuously maintain its internal conditions. Each physiological condition has a particular set point, ...

Negative and Positive Feedback

Homeostatic Imbalance

Homeostasis is the maintenance of a stable internal environment within the body, which is crucial for the proper functioning of cells, tissues, organs, ...

pH Homeostasis

Acid-base homeostasis is essential for maintaining normal physiological activities in humans. The pH of various body fluids is strictly regulated because ...

homeostatic-imbalances-in-body-temperature

Homeostatic Imbalances in Body Temperature

Hyperthermia is an umbrella term for elevated body temperature that occurs when heat production exceeds the body&#39;s ability to dissipate it.
...

Regulation of Food Intake

The hypothalamus releases peptides influencing feeding behavior.
Two hypothalamic neuronal groups participate in this process.
Neuropeptide Y (NPY) and ...

Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis in living organisms. Examples of investigations could include heart rate responses to exercise, stomate responses to moisture and temperature, root development in response to water levels, or cell response to hypertonic and hypotonic environments.

HS-LS1-3

What is the Cell Cycle?

The cell cycle refers to the sequence of events occurring throughout a typical cell&#8217;s life. In eukaryotic cells, the somatic cell cycle has two ...

Use a model to illustrate the role of the cell cycle and differentiation in producing and maintaining complex organisms. Emphasis is on conceptual understanding that mitosis passes on genetically identical materials via replication, not on the details of each phase in mitosis.

HS-LS1-4

Antibiotic Resistance in Cloning

Description

Transcript

Tags

More videos by Standards