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 variation génétique provient de différences dans les séquences d’ADN entre les individus, qui sont essentielles à l’adaptation et à l’évolution des espèces.
Les variations génétiques proviennent du fait que les ovaires produisent des ovules et que les testicules produisent des spermatozoïdes par un processus appelé méiose.
Les ovaires libèrent des ovules qui peuvent potentiellement être fécondés avec des spermatozoïdes lorsqu’ils traversent les trompes de Fallope jusqu’à l’utérus.
Chaque ovule et spermatozoïde contribue à 23 chromosomes, qui sont des séquences d’ADN qui codent pour des gènes.
Les allèles sont les différentes versions de ces gènes qui influencent des traits spécifiques. Par exemple, le gène déterminant la couleur des yeux a divers allèles, tels que ceux des yeux bleus ou bruns.
La fécondation aboutit à un zygote avec 46 chromosomes, combinant le matériel génétique des deux parents.
Les individus avec deux allèles identiques pour un gène sont appelés homozygotes, tandis que ceux avec deux allèles différents sont hétérozygotes.
Par exemple, les individus avec deux allèles mutés d’un gène de la globine développent une maladie génétique appelée anémie falciforme, tandis que les individus hétérozygotes qui portent un allèle sain et un allèle muté ne présentent pas de symptômes graves de la maladie.

variation génétique

La variation génétique est la diversité des séquences d'ADN que l'on retrouve chez les individus d'une même espèce. Cette diversité est essentielle à la survie d'une espèce, car elle permet aux organismes de s'adapter aux changements environnementaux. La variation génétique commence avec la fécondation, lorsqu’un ovule et un spermatozoïde fusionnent. Chacune de ces cellules porte 23 chromosomes, jusqu'à en former 46 dans l'ovule fécondé. Les chromosomes sont de longs brins d'ADN qui contiennent des gènes qui sont les unités de base de l'hérédité.

Les gènes existent sous différentes formes appelées allèles, qui peuvent influencer divers traits, comme la couleur des cheveux et des yeux, ou même le risque de certaines maladies. Le mélange spécifique d'allèles hérités des deux parents crée un ensemble unique d'informations génétiques qui codent l'apparence physique et les caractéristiques de santé de la progéniture, appelé phénotype.

Le génotype est la constitution génétique spécifique d'un individu, déterminée par les allèles reçus des deux parents. Cette combinaison génétique affecte la manière dont les traits sont exprimés. Par exemple, la couleur des yeux est influencée par les allèles de chaque parent. Si les deux parents donnent un allèle récessif pour les yeux bleus, leur enfant aura probablement les yeux bleus. À l'inverse, si un allèle est pour les yeux marron et l'autre pour les yeux bleus, l'allèle marron dominant domine généralement, ce qui donne les yeux marron à l'enfant.

Les termes homozygote et hétérozygote décrivent si les deux allèles d'un gène particulier sont identiques ou différents. Homozygote signifie que les deux allèles sont identiques, tandis qu'hétérozygote signifie qu'ils sont différents. Cette distinction peut avoir un impact significatif sur la santé d'un individu. Par exemple, l'anémie falciforme est une maladie dans laquelle les individus ayant deux allèles récessifs pour le gène de l'hémoglobine sont atteints de la maladie. Cependant, les personnes hétérozygotes, porteuses d'un allèle normal et d'un allèle drépanocytaire, ne présentent pas de symptômes de la maladie, mais bénéficient d’une protection contre le paludisme, ce qui est avantageux dans les régions où le paludisme est fréquent.

Variation génétique

La variation génétique provient de différences dans les séquences d’ADN entre les individus, qui sont essentielles à l’adaptation et à l’évolution des espèces.
Variations génétiques...

Education

Enseignement

JoVE Core

Introduction to Psychology

Introduction à la psychologie

Unit 1

Unité 1

Biopsychology

Biopsychologie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

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

introduction to biological bases of psychology

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genetic variation

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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.

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The DNA Helix

Overview

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DNA Packaging

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Organization of Genes

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Karyotyping

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RNA Structure

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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

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Types of RNA

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MicroRNAs

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Transcription

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Translation

Lesson: Translation
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Bacterial Transformation

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What is Gene Expression?

Overview
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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

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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

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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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