Name: genotype, phenotype, and inheritance
Uploaded: 2019-03-11T09:21:16.000Z
Duration: 1 min 11 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Life Science

LS.10

LS.10.c

Genetic Lingo

대립 형질은 동일 유전자의 다른 형태이다각 부모로부터 하나를 받아서이배체 생물이 생겨나는데유전자마다 두 대립 형질이 같은 장소에 있는 것이다각 쌍은 특정 유전자의 유전자형으로 알려져 있고물리적 관찰 가능한 표현인 표현형은이를테면 눈 색깔은유전 조합에 의하여 결정된다이 경우에 유전자 중의 하나는 갈색과 파란색의두 대립 형질을 포함한다두 형태가 다 똑 같으면유전자형은 동형 접합체라고 하고두 쌍이 다르면 이질 접합체라고 한다흥미롭게도, 눈 색깔 같은 동일한 표현형을여러가지 유전자형으로 표현할 수가 있다이유는 우성 대립 형질인 갈색이대문자로 표현되어 있는데소문자로 표시된 열성 대립 형질인파란색보다 우세하기 때문이다그래서, 열성 대립 형질이 표출되는 유일한 방법은둘 다 열성일 때 뿐이다

페이, 데이비드, 앤디 스펜서. 우성 돌연변이. 웜북, 2006. [<a href="https://www.ncbi.nlm.nih.gov/books/NBK19699/" target="__blank">소스</a>].

유전학의 용어

<h4>개요</h4>
 
 유기체가 각 유전자(gene)의 두 변이(variant), 즉 대립유전자(allele)를 부모로부터 각각 하나씩 물려받으면 이배체(diploid)라 부릅니다. 이 두 개의 대립유전자는 유전자의 유전자형(genotype)을 구성합니다. 유전자형이라는 용어는 또한 유기체가 가진 유전자의 모든 집합을 지칭하는 데도 사용됩니다. 두 개의 동일한 대립유전자를 가진 이배체 유기체는 동형접합적(homozygous) 유전자형을 가지고 있는 반면, 두 개의 다른 대립유전자를 가지면 이형접합적(heterozygous) 유전자형을 가지게 됩니다. 유전자형에서 발생하는 관찰 가능한 형질(trait)은 표현형(phenotype)이라고 불리며, 환경적 요인에 의해서도 영향을 받을 수 있습니다. 표현형을 나타내기 위해 하나의 대립유전자 사본만 필요한 경우 대립유전자를 현성(dominant; 눈에 띄는 성질)이라 부르고 표현형을 나타내는데 두 개의 대립유전자 사본이 필요한 경우 대립유전자를 잠성(recessive; 숨어 있는 성질)이라 부릅니다. (주: dominant를 우성이라 부르고 recessive를 열성이라 부르는 경우가 아직 많지만, 과학적으로 현성/잠성이란 단어가 현상을 더 정확하게 정의하는 단어입니다. 게다가 우성/열성이란 단어는 차별로 이어질 수 있기 때문에 현성/잠성이란 표현으로 개선해야 합니다.)
 
 <h4>대립유전자는 표현형에 영향을 미칠 수 있습니다</h4>
 
 인간, 대부분의 동물, 그리고 여러 식물을 포함한 이배체 유기체는 체세포(somatic cell; 즉 생식세포가 아닌)에 중복된 염색체 세트를 가지고 있습니다. 이러한 중복 염색체는 비슷한 길이, 동원체(centromere) 위치, 유전자 위치가 비슷한 상동적(homologous)인 염색체입니다. 이배체 생물은 각 유전자의 두 가지 버전을 물려받으며, 각 부모로부터 하나씩 물려받습니다. 이 두 유전자 변이 또는 대립유전자는 2개의 상동 염색체(homologous chromosome; 상동체)안에 동일한 위치 또는 상대적 유전자자리(relative locus)에 자리 잡고 있습니다. 각 염색체는 많은 유전자자리(locus; 유전자좌)가 포함되어 있으며, 대개 유전자 당 여러 가지 대립유전자가 존재할 가능성이 있습니다.
 
 이배체 유기체가 물려받는 2개의 대립유전자는 해당 유전자자리에서 유전자형을 구성합니다. 유전자형이라는 용어는 유기체의 유전자의 전체 집합을 뜻하기도 합니다. 서로 다른 유전자형은 각각 뚜렷한 표현형, 즉 관찰 가능한 특성(예를 들어, 눈 색깔)을 가져올 수 있습니다. 표현형은 유전자형의 결과로 나타나지만, 때론 여러 유전자형이 같은 표현형을 유발할 수도 있습니다. 표현형은 또한 종종 환경적 요인의 영향을 받습니다.
 
 <h4>유전자형은 두 개의 동일한 또는 다른 대립유전자로 구성될 수 있습니다</h4>
 
 한 유전자에 대한 두 개의 대립유전자는 동일하거나 구별되는 뉴클레오타이드 서열(nucleotide sequence)을 가질 수 있습니다. 2개의 동일한 대립유전자를 가진 유기체는 동형접합적(homozygous) 유전자형을 가지고 있습니다 (또는 이를 '유기체가 동형접합자(homozygote)이다'라고 표현할 수 있습니다). 2개의 다른 대립유전자를 가진 생물은 이형접합적(heterozygous) 유전자형을 가지고 있습니다 (또는 이를 '유기체가 이형접합자(heterozygote)이다'라고 표현할 수 있습니다). 2개의 대립유전자가 서로 다르고 (이형접합적 유전자형) 그중 하나만 표현형에 영향을 미치는 경우엔 표현형에 영향을 미치는 대립유전자를 현성(dominant)이라 합니다. 표현형에 영향을 주지 않는 다른 대립유전자는 잠성(recessive)이라 합니다.
 
 원래 눈동자 색깔은 단일 유전자에 의해 결정된다고 생각되어서, 유전적 현성과 잠성을 설명하는 예로 자주 사용했습니다. 그러나 과학자들은 현재까지 눈동자 색깔을 조절하는 적어도 8개의 유전자를 발견했습니다. OCA2 유전자는 청갈색 눈동자 색깔 스펙트럼에 다양성을 일으키는 원인 중 4분의 3정도를 담당하지만, 때때로 다른 유전자가 이런 효과를 변경하거나 중단할 수 있습니다. 위와 같이 눈동자 색깔은 단일 유전자의 영향을 받는건 아니지만 그래도 여전히 현성과 잠성을 설명하는 유용한 예가 될 수 있습니다.
 
 (다음 예는 유전자형과 표현형의 관계를 설명하기 위해 단순화된 눈동자 색상을 사용합니다. 갈색 눈동자의 대립유전자는 B로 표시하고 파란 눈동자의 대립유전자는 b로 표시합니다). 이형접합자는 한 부모에게 현성 대립유전자를, 그리고 다른 부모에게 잠성 대립유전자를 물려받아 유전자형 Bb를 가집니다. 이 사람은 갈색 눈동자를 가지고 있으며, 따라서 현성 표현형(dominant phenotype)을 가집니다. 현성 대립유전자(B)는 잠성 대립유전자(b)의 지시를 무시하거나 “숨깁”니다. 따라서 파란 눈동자를 가진 사람은 반드시 유전자형 bb를 가지고 있지만, 갈색 눈동자를 가진 사람은 유전자형 BB 또는 Bb를 가질 수 있습니다.
 
 <h4>현성/잠성 질병 유전형식은 질병 위험과 관련이 있습니다</h4>
 
 대부분의 형질은 단일 원인 유전자(causal gene)가 아니라 여러 유전자에 의해 제어되지만, 이러한 유전 원칙은 질병과 관련해 나타날 수 있는 결과의 확률을 예측하는 데 도움이됩니다. 예를 들어, 헌팅턴 병(Huntington disease, 줄여서 HD)은 진통제되지 않는 움직임과 인지 및 정서적 장애를 일으키는 진행성 신경퇴행성 질환입니다. 헌팅턴 병은 단일 유전자 (HTT)의 돌연변이(mutation)에 의해 발생되므로 단일 유전자 질환(single gene disorder)으로 간주되지만, 다른 유전자의 영향을 받아 발병과 진행이 변합니다. 헌팅턴 병은 현성 돌연변이에 의해 발생합니다. 즉, 하나의 돌연변이 대립유전자가 질병의 발현에 연결됩니다. 부모가 정상적인 유전자 변이와 돌연변이 된 유전자 변이를 가지고 있으면 자식이 돌연변이 대립유전자를 물려받고 질병을 가질 가능성이 50%입니다. 헌팅턴 병은 일반적으로 중년에서 노년까지 나타나지 않습니다. 따라서 불편하지만 영향을 받은 부모를 가진 사람은 자신이 원인이 되는 대립유전자를 가지고 있는지 여부를 확인하고 가족계획을 세우기 위해 유전자 검사를 받을 수 있습니다.

개요

유기체는 각 유전자의 두 가지 변이 또는 대립유전자를 각 부모로부터 하나씩 물려받는 경우 이배체입니다. 이 두 대립유전자는 유전자형을 구성합니다 ...

Education

교육

JoVE Core

Biology

생물학

Genetics

유전학

Classical and Modern Genetics

고전 유전학과 현대 유전학

KEY TERMS AND CONCEPTS

주요 용어 및 개념

genotype, phenotype, and inheritance

Genotype, phenotype, and inheritance help explain how traits and disease risk are passed from parents to offspring. In diploid organisms, including humans, most other animals, and many plants, somatic cells carry a duplicate set of chromosomes. These chromosome pairs are homologous, with similar length, centromere position, and gene locations.

Diploid organisms inherit two versions of each gene, one from each parent. These versions are called alleles, and they sit at the same relative locus, or position, on homologous chromosomes. The two alleles at a locus make up an organism’s genotype for that gene. Genotype can also mean the organism’s complete set of genes.

Different genotypes can produce different phenotypes, which are the observable traits of an organism. Eye color is one example. Phenotypes can also be shaped by environmental factors, and more than one genotype can sometimes lead to the same phenotype.

For a given gene, the two alleles may be identical or different. A homozygous genotype has two identical alleles. A heterozygous genotype has two different alleles. If a heterozygote shows the effect of only one allele, that allele is dominant, and the other is recessive.

Brown and blue eye color are often used to show dominance and recessiveness. In this simplified example, B stands for the brown-eye allele and b stands for the blue-eye allele. A person with Bb has brown eyes because the dominant B allele hides the blue-eye instructions from b. A person with blue eyes must have bb, while a person with brown eyes can have BB or Bb.

These same ideas also help explain disease inheritance. Huntington disease is a progressive neurodegenerative condition that can cause uncontrolled movements and changes in thinking and mood. It is a single-gene disorder caused by a mutation in the HTT gene, although other genes can affect when it starts and how it progresses. The mutation is dominant, so one mutated allele can cause the disease. If a parent has one normal allele and one mutated allele, each child has a 50% chance of inheriting the mutation. Because Huntington disease often appears in middle to late life, genetic testing can help affected families with planning.

Genotype, Phenotype, and Inheritance

genetic lingo

Genotype, phenotype, and inheritance help explain how traits and disease risk are passed from parents to offspring. In diploid organisms, including humans, most other animals, and many plants, somatic cells carry a duplicate set of chromosomes. These chromosome pairs are homologous, with similar length, centromere position, and gene locations. Diploid organisms inherit two versions of each gene, one from each parent. These versions are called alleles, and they sit at the same relative locus,...

punnett squares

Punnett Squares for Predicting Traits

Punnett squares help predict which traits offspring may inherit from two parents. They show possible genotypes, which are pairs of alleles, and can also show the chance of a phenotype, or visible trait, when the inheritance pattern is known. These grids work best for traits controlled by a single gene locus and passed on independently during meiosis. Punnett squares were developed in the early 1900s by Reginald Punnett. His work came after Gregor Mendel’s pea plant experiments revealed the...

monohybrid crosses

Mendel’s Pea Plant Inheritance Ratios

Gregor Mendel used pea plants to study how traits are passed from parents to offspring. His breeding experiments in the 1850s and 1860s showed that inheritance follows clear patterns. He crossed true-breeding plants that differed in one trait and found that dominant traits can hide recessive traits. Mendel focused on seven pea plant traits, and each trait had two forms controlled by a single gene locus. He noticed that true-breeding plants always produced offspring with the same phenotype, or...

dihybrid crosses

Mendel's Law of Independent Assortment

Mendel’s law of independent assortment explains how two traits can be inherited separately. Gregor Mendel tested this idea with pea plants that differed in two characteristics, such as pea color and pea shape. He used true-breeding parents that were homozygous for both traits but showed different phenotypes. In one example, Mendel crossed round, yellow peas with wrinkled, green peas. The parental generation had RRYY and rryy genotypes. Their first-generation offspring were all dihybrids,...

law of segregation

Mendel’s Pea Cross Ratios

Mendel’s pea plant crosses show how traits can disappear in one generation and return in the next. When he crossed plants, one parental trait sometimes seemed to vanish in the F1 generation and reappear in the F2 generation. Mendel used this pattern to explain why some traits are dominant and others are recessive. He proposed that traits are controlled by alleles, which are different versions of a gene. An organism inherits two copies of each gene, one from each parent. In his model, a...

law of independent assortment

Mendel’s Dihybrid Cross and Trait Ratios

Mendel’s dihybrid cross shows how two traits are inherited at the same time. A dihybrid cross is a cross in which both parents are homozygous for two distinct traits, and the F1 generation is heterozygous for both traits. Mendel used pea plants with round yellow peas and wrinkled green peas as an example. One parent had genotype YYRR, and the other had genotype yyrr. In the F1 generation, every plant showed the dominant traits, so the plants were YyRr and had yellow, round peas. The F2...

probability laws

Inheritance Risk with Sum and Product Rules

Inheritance risk can be calculated with the sum rule and the product rule. The sum rule applies to mutually exclusive events, or events that cannot happen at the same time. The product rule applies to independent events, or events that do not affect one another. These rules describe theoretical probability, which is the chance of an event before it happens. Empirical probability is different because it is based on events that have already occurred. These probability rules are useful in...

test cross

Using Test Crosses to Identify Genotypes

Test crosses are used to identify the genotype of an organism with a dominant trait. A genotype is the pair of alleles inherited for a gene, and alleles are different forms of the same gene. In diploid organisms, including humans, each gene usually has two alleles, one from each parent. An allele is recessive when its effect is hidden by another allele at the same gene location. Pea plants provide a clear example with flower color. White flowers are recessive, because one copy of the purple...

polygenic traits

Polygenic Traits in Human Height

Polygenic traits are traits controlled by more than one gene. Human height is a clear example of this kind of inheritance. Because many genes work together, the final trait can vary a lot from person to person. Researchers have found hundreds of loci, or gene locations, that influence height. There are likely many more that have not yet been identified. Many of these genes affect cartilage in the growth plates of the long bones in the arms and legs, either directly or indirectly. Height is...

pedigree analysis

Reading Family Traits in Pedigrees

Pedigrees are family trees used to track how a trait passes through generations. They help scientists and students see whether a trait is dominant or recessive, whether it is autosomal or sex-linked, what genotypes family members may have, and what phenotypes may appear in future generations. For families with a history of inherited disease, this information can be important for family planning. In plants and animals, inheritance is often studied with crosses. Monohybrid crosses can show...

multiple allele traits

Blood Type and Allele Interactions

Multiple alleles can shape traits through blood type, sickle cell anemia, incomplete dominance, and codominance. Multiple allelism means a gene has three or more allelic forms. Diploid organisms, including humans, usually carry only two alleles for each gene, but many human genes exist in multiple forms in the population. Human blood type is a clear example of multiple allelism. The blood type gene has three alleles: I A , I B , and i. These alleles help determine which blood type a person has...

epistasis

Gene Masking in Rabbit Fur Color

Epistasis describes how one gene can mask or change the effect of another gene. In high school genetics, this helps explain why many traits do not follow a simple single-gene pattern. Instead, alleles at different locations can work together to shape the final phenotype. Mendel studied seven unrelated pea traits, but most traits involve multiple gene interactions. Epistasis often happens when one gene interferes with the expression of another gene. It can also occur when genes are part of the...

nature and nurture

Genes and Environment Shape Height

Genes and environment both shape human height and other traits. Genes are the inherited instructions we get from our parents. Environment includes factors such as diet, stress, and social conditions. Many phenotypes, or observable traits, reflect both influences. Some also show up later in life, including cancer and other diseases. Height is a clear example of this interaction. Scientists estimate that 70-90% of height variation comes from genetic differences among people. The remaining 10-30%...

pleiotropy

SOX10 and Multiple Traits in Pleiotropy

Pleiotropy is when one gene affects more than one trait. The SOX10 gene is a clear example because it can influence pigmentation, hearing, and intestinal movement. These traits may seem unrelated, but they can all be linked to the same gene change. In humans, a deleted region in SOX10 can cause Waardenburg Syndrome Type 4, or WS4. WS4 is an autosomal recessive disorder, which means a person usually inherits two altered copies of the gene. Common signs include a white forelock,...

sex-linked disorders

X- and Y-Linked Disorder Patterns

X- and Y-linked disorders come from mutations in genes on the sex chromosomes. These genes, like those on autosomes, are needed for normal body function. When a mutation causes a biological problem, the condition is called sex-linked. Y-linked disorders come from changes in the Y chromosome. They affect only males, because only males carry a Y chromosome. Mutations in this small chromosome can affect male sexual function and secondary sex characteristics. One example is Y-chromosome...

x-linked traits

X-Linked Inheritance in Families

X-linked inheritance explains how traits on the X chromosome are passed through families. In most mammalian species, females have two X sex chromosomes, while males have one X and one Y. A mutation on one X chromosome may be masked in females by a normal allele on the other X. In males, that same mutation is more likely to show because there is no second normal X to balance it. Traits caused by changes on the X chromosome are called X-linked traits. Color blindness is a well-studied example.

x-inactivation

Barr Bodies and X-Chromosome Balance

Barr bodies and X-chromosome balance help explain how female mammalian cells control gene activity from the X chromosome. The human X chromosome carries far more genes than the Y chromosome. Because males usually have one X chromosome and females have two, females would make twice as many of some proteins without a control system. To prevent that imbalance, female mammalian cells inactivate nearly all the genes on one X chromosome during early embryonic development. The inactive X condenses...

non-nuclear inheritance

Maternal DNA in Mitochondria and Chloroplasts

Maternal DNA in mitochondria and chloroplasts explains how some genes are inherited outside the nucleus. Most DNA is in the nucleus, but mitochondria and chloroplasts in the cell cytoplasm also carry their own DNA and can copy it independently of nuclear DNA. Mitochondria are found in both plant and animal cells. They are called the powerhouses of eukaryotic cells because they break down glucose to make energy for cellular activity. Mitochondrial DNA has about 37 genes, and many help with...

chromosomal theory of inheritance

How Genes Map to Chromosomes

Genes map to chromosomes, and this idea explains how Mendel’s inheritance patterns work. Gregor Mendel published his pea plant breeding results in 1866. He showed that physical traits follow predictable patterns. At the time, scientists did not yet know that genes existed. Mendel used the word "factors" for the hereditary units he studied. The details behind Mendel’s laws of segregation and independent assortment were still unknown for many years. In the late 1800s, better microscopes and...

key terms and concepts

Learn how genotypes, alleles, dominant and recessive traits, and Huntington disease inheritance connect genes to visible traits and disease risk.

Genotype, Phenotype, and Inheritance | 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

JoVE Core 시리즈는 생물학의 주요 개념을 설명하는 300개가 넘는 간결하고 이해하기 쉬운 애니메이션 비디오 강의와 오늘날 실험실에서 수행된 실제 연구 실험을 보여주는 150개가 넘는 과학자 활동 비디오를 통해 생물학에 활기를 불어 넣습니다.

Next Generation Science Standards

High School

heredity-inheritance-and-variation-of-traits

Heredity: Inheritance and Variation of Traits

HS-LS3-1

Florida Department of Education

SC.912.L.16

SC.912.L.16.1

new-york-state-science-learning-standards

New York State Science Learning Standards

Inheritance and Variation of Traits

HS-LS3-1.

myJoVE Corporation

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. ...

Replication in Prokaryotes

Overview

DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to ...

Replication in Eukaryotes

Overview

In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high ...

Proofreading

Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA ...

Mutations

Overview

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

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

Bacterial Transformation

In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two ...

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 ...

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 ...

RNA Splicing

Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called ...

Epigenetic Regulation

Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like ...

RNA Interference

RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its ...

Operons

Prokaryotes can control gene expression through operons&mdash;DNA sequences consisting of regulatory elements and clustered, functionally related ...

Proteins: From Genes to Degradation

The student will investigate and understand that organisms reproduce and transmit genetic information to new generations. Key ideas include DNA has a role in making proteins that determine organism traits;

LS.10.a

What is Meiosis?

Meiosis is the process by which diploid cells divide to produce haploid daughter cells. In humans, each diploid cell contains 46 chromosomes, half from ...

Meiosis I

Meiosis is a carefully orchestrated set of cell divisions, the goal of which&#x2014;in humans&#x2014;is to produce haploid sperm or eggs, each containing ...

Meiosis II

Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 ...

Crossing Over

Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where ...

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed ...

The student will investigate and understand that organisms reproduce and transmit genetic information to new generations. Key ideas include the role of meiosis is to transfer traits to the next generation; and

LS.10.b

Overview

An organism is diploid if it inherits two variants, or alleles, of each gene, one from each parent. These two alleles constitute the genotype ...

Punnett Squares

Overview

A Punnett square displays the possible genotypes offspring can inherit from two parental genotypes. If a trait&#x2019;s inheritance pattern ...

Monohybrid Crosses

Overview

In the 1850s and 1860s, Gregor Mendel investigated inheritance by performing monohybrid crosses in pea plants. He crossed two plants that were ...

Dihybrid Crosses

Overview

To determine whether traits are inherited together or separately, Gregor Mendel crossed pea plants that differed in two traits. These parental ...

Law of Segregation

When crossing pea plants, Mendel noticed that one of the parental traits would sometimes disappear in the first generation of offspring, called the F1 ...

Law of Independent Assortment

While Mendel&#x2019;s Law of Segregation states that the two alleles for one gene are separated into different gametes, a different question of how ...

Test Cross

Alleles are different forms of the same gene. Humans and other diploid organisms inherit two alleles of every gene, one from each parent.

An allele is ...

Pedigree Analysis

Overview

A pedigree is a diagram displaying a family&#x2019;s history of a trait. Analyzing pedigrees can reveal (1) whether a trait is dominant or ...

X-linked Traits

In most mammalian species, females have two X sex chromosomes and males have an X and Y. As a result, mutations on the X chromosome in females may be ...

Sex-linked Disorders

Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological ...

Nature and Nurture

Many human characteristics, like height, are shaped by both nature&mdash;in other words, by our genes&mdash;and by nurture, or our environment. For ...

The student will investigate and understand that organisms reproduce and transmit genetic information to new generations. Key ideas include Punnett squares are mathematical models used to predict the probability of traits in offspring.

Genotype, Phenotype, and Inheritance

Description

Transcript

More videos by Standards