Name: how alleles shape inherited traits
Uploaded: 2024-08-29T22:13:37.000Z
Duration: 1 min 25 s
Channel: JoVE

K12 Standards

Arizona Science Standards

High School

Life Science

HS+B.L3

HS+B.L3U1.10

Genetic Variation

La variazione genetica deriva dalle differenze nelle sequenze di DNA tra gli individui, che sono essenziali per l'adattamento e l'evoluzione delle specie.
Le variazioni genetiche hanno origine quando le ovaie producono ovuli e i testicoli producono spermatozoi attraverso un processo chiamato meiosi.
Le ovaie rilasciano ovuli che possono potenzialmente fecondarsi con lo sperma mentre viaggiano attraverso le tube di Falloppio fino all'utero.
Ogni ovulo e spermatozoo contribuisce con 23 cromosomi, che sono sequenze di DNA che codificano i geni.
Gli alleli sono le diverse versioni di questi geni che influenzano tratti specifici. Ad esempio, il gene che determina il colore degli occhi ha vari alleli, come quelli per gli occhi azzurri o marroni.
La fecondazione si traduce in uno zigote con 46 cromosomi, combinando il materiale genetico di entrambi i genitori.
Gli individui con due alleli identici per un gene sono chiamati omozigoti, mentre quelli con due alleli diversi sono eterozigoti.
Ad esempio, gli individui con due alleli mutati di un gene della globina sviluppano una malattia genetica chiamata anemia falciforme, mentre gli individui eterozigoti che portano un allele sano e uno mutato non mostrano sintomi gravi della malattia.

variazione genetica

La variazione genetica è la diversità nelle sequenze di DNA riscontrate tra gli individui della stessa specie. Questa diversità è fondamentale per la sopravvivenza di una specie perché aiuta gli organismi ad adattarsi ai cambiamenti ambientali. La variazione genetica inizia con la fecondazione, dove un ovulo e uno spermatozoo si fondono. Ognuna di queste cellule trasporta 23 cromosomi, fino a 46 nell'ovulo fecondato. I cromosomi sono lunghi filamenti di DNA che contengono i geni, le unità di base dell'ereditarietà.

I geni esistono in diverse versioni chiamate alleli, che possono influenzare vari tratti, come il colore dei capelli e degli occhi, o persino il rischio di alcune malattie. La specifica combinazione di alleli ereditata da entrambi i genitori crea un set unico di istruzioni genetiche, che modellano l'aspetto fisico e le caratteristiche di salute della prole, definite fenotipo.

Il genotipo è la composizione genetica specifica di un individuo, determinata dagli alleli ricevuti da entrambi i genitori. Questa combinazione genetica influenza il modo in cui vengono espressi i tratti. Ad esempio, il colore degli occhi è determinato dagli alleli per il colore degli occhi che ogni genitore contribuisce. Se entrambi i genitori forniscono un allele recessivo per gli occhi azzurri, è probabile che il loro bambino abbia gli occhi azzurri. Al contrario, se un allele è per gli occhi marroni e l'altro per gli occhi blu, di solito prevale l'allele marrone dominante, con conseguenti occhi marroni per il bambino.

I termini omozigote ed eterozigote descrivono se i due alleli per un gene particolare sono uguali o diversi. Essere omozigote significa che entrambi gli alleli sono identici, mentre eterozigote significa che sono diversi. Questa distinzione può avere un impatto significativo sulla salute di un individuo. Per esempio, l'anemia falciforme è una condizione in cui gli individui con due alleli recessivi per il gene dell'emoglobina hanno la malattia. Tuttavia, coloro che sono eterozigoti, e che portano un allele normale e uno falciforme, non mostrano sintomi della malattia ma hanno un vantaggio protettivo contro la malaria, il che è utile nelle aree in cui la malaria è comune.

Variazione genetica

La variazione genetica deriva dalle differenze nelle sequenze di DNA tra gli individui, che sono essenziali per l'adattamento e l'evoluzione delle specie.
Variazioni genetiche ...

Education

Didattica

JoVE Core

Introduction to Psychology

Introduzione alla psicologia

Unit 1

Unità 1

Biopsychology

Biopsicologia

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

how alleles shape inherited traits

Genetic variation helps explain why individuals in the same species can look and act differently. It comes from differences in DNA sequences. This diversity matters because it helps a species survive and adapt when the environment changes.

Variation starts at fertilization, when an egg and sperm cell join. Each of these cells carries 23 chromosomes, so the fertilized egg can have up to 46 chromosomes. Chromosomes are long DNA strands that contain genes, which are the basic units of heredity.

Genes can appear in different versions called alleles. These alleles can affect traits such as hair and eye color. They can also influence the risk of certain diseases. The combination of alleles inherited from both parents creates a unique set of genetic instructions. These instructions shape an offspring’s physical appearance and health traits, which are called the phenotype.

An individual’s genotype is the specific genetic makeup they inherit from both parents. Genotype affects how traits are expressed. For example, eye color depends on the alleles each parent contributes. If both parents pass on a recessive allele for blue eyes, the child is likely to have blue eyes. If one allele is for brown eyes and the other is for blue eyes, the dominant brown allele usually leads to brown eyes.

The terms homozygous and heterozygous describe whether the two alleles for a gene are the same or different. Homozygous means both alleles are identical. Heterozygous means the alleles are different. This difference can affect health. People with two recessive alleles for the hemoglobin gene can have sickle cell anemia. People with one normal allele and one sickle cell allele do not show symptoms, but they have a protective advantage against malaria. This advantage is helpful in areas where malaria is common.

How Alleles Shape Inherited Traits

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key terms and concepts

Learn how alleles, genotype, and phenotype work together to shape inherited traits, from eye color to sickle cell anemia and malaria protection.

How Alleles Shape Inherited Traits | JoVE K12

JoVE Core Introduction to Psychology offers an engaging learning experience on the fundamental principles of psychology through concise video lessons. Students will explore important topics such as cognitive processes, emotional regulation, and neural mechanisms, establishing a strong foundation in the study of the mind and human behavior. This series provides an accessible and captivating approach to grasp the essential concepts of the discipline.

introduction to psychology

Next Generation Science Standards

heredity-inheritance-and-variation-of-traits

Heredity: Inheritance and Variation of Traits

HS-LS3-2

Florida Department of Education

SC.912.L.15

SC.912.L.15.15

SC.912.L.16

SC.912.L.16.17

new-york-state-science-learning-standards

New York State Science Learning Standards

Inheritance and Variation of Traits

HS-LS3-1.

What is Population Genetics?

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Hardy-Weinberg Principle

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Mutation, Gene Flow, and Genetic Drift

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Genetic variation stems from differences in DNA sequences among individuals, which are essential for species adaptation and evolution.
Genetic variations ...

Heritability

Heritability measures the genetic influence on traits or physical characteristics such as height or eye color.
Heritability can vary depending on the ...

Natural Selection and Adaptation

Natural selection drives evolution by supporting organisms that are best adapted to their environments, enhancing their survival and reproduction rates.
...

Natural Selection and Mating Preferences

The principle of natural selection suggests that organisms better adapted to their environment are more likely to survive and reproduce.
Evolutionary ...

Use mathematics and computational thinking to explain the variation that occurs through meiosis and calculate the distribution of expressed traits in a population.

Genomic DNA in Prokaryotes

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Genomic DNA in Eukaryotes

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The DNA Helix

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 ...

Organization of Genes

Overview

The genomes of eukaryotes can be structured in several functional categories. A strand of DNA is comprised of genes and intergenic regions. ...

Karyotyping

Describing the number and physical features of chromosomes can reveal abnormalities that underlie genetic diseases. This description is facilitated by ...

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 ...

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 ...

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns&mdash;non-coding regions of a gene&mdash;or intergenic regions&mdash;stretches of DNA ...

Transcription

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

Translation

Lesson: Translation
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Bacterial Transformation

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What is Gene Expression?

Overview
Gene expression is the process in which DNA&nbsp;directs the synthesis of functional products, that is, proteins. Cells can regulate gene ...

The Central Dogma

Overview

The central dogma of biology states that information encoded in the DNA is transferred to messenger RNA (mRNA), which then directs the synthesis ...

Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of ...

Construct an explanation for how the structure of DNA and RNA determine the structure of proteins that perform essential life functions.

HS+B.L3U1.11

Mutations

Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations ...

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Genome Size and the Evolution of New Genes

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Evolutionary Relationships through Genome Comparisons

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Genome Copying Errors

DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a ...

Multi-species Conserved Sequences

Next-generation sequencing technologies have created large genomic databases of a variety of animals and plants. Ever since the human genome project was ...

Gene Duplication and Divergence

The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of ...

Exon Recombination

The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new ...

Analyze and interpret data on how mutations can lead to increased genetic variation in a population.

HS+B.L3U1.12

How Alleles Shape Inherited Traits

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