CEL MOL GENETIC MUTATIONS

Genetics

The scientific study of heredity

Prophase I

crossing over, which occurs during what stage in meiosis?

Linkage

This refers when genes on the same chromosome tend to be inherited together

Crossing Over

This refers to the process during meiosis, where chromosomes exchange sections, increasing genetic variation and allowing genes to assort more independently

cytology

These discoveries (linkage and crossing over) bridged Mendelian genetics with _____, explaining how inheritance works at the molecular level.

True

Hemophilia Is an X-Linked Recessive Disorder

TRUE OR FALSE

True

In hemophilia,

• If a female has one normal allele and one faulty allele, she is a carrier but does not usually show symptoms.

TRUE OR FALSE

True

Males cannot pass hemophilia to their sons because they contribute a Y chromosome, not an X chromosome. However, all of their daughters will be carriers if they inherit the affected X chromosome

TRUE OR FALSE

Gene therapy research

Treatment and Management of Hemophilia

• Scientists are exploring genetic treatments to permanently correct the faulty gene

Desmopressin (DDAVP) therapy

Treatment and Management of Hemophilia

• A medication that helps release stored clotting factors

Clotting factor replacement therapy

Treatment and Management of Hemophilia

• Injecting missing clotting factors into the bloodstream

Continuous variation

This refers to traits that vary gradually over a range and do not fall into distinct categories.

multiple genes

Most traits that show continuous variation are controlled by ____, each with a small effect on the phenotype

Epistasis

This occurs when one gene can mask or modify the expression of another gene. This means that the phenotype produced by one gene is influenced by the genotype of another gene

Complementation

Other forms of Gene interactions:

• Where two different genes interact to produce a complete and functional phenotype

Additive Gene Action

Other forms of Gene interactions:

Where the combined effect of two or more genes is equal to the sum of their individual effects

Environmental effects

This refers to the influence of external conditions that can affect the way genes are expressed, altering the phenotype without changing the genotype

Gene interaction

This occurs when the effects of one gene are influenced by one or more other genes. This can lead to complex patterns of inheritance that do not follow simple Mendelian ratios

polygenic inheritance

In _____ _____, several genes work together to produce a continuous range of phenotypes

co dominance

this refers when to traits are expressed equally or fully rather than blending

incomplete dominance

This occurs when a heterozygous genotype produces a phenotype that is intermediate between the dominant and recessive traits

true

The closer two genes are on a chromosome, the less likely they are to be separated by crossing over. The farther apart they are, the more likely they will assort independently

TRUE OR FALSE

chiasmata

•During meiosis, homologous chromosome pairs line up and swap genetic material at points called ____

linkage

Some genes are located on the same chromosome. If genes are physically close to each other, they tend to be inherited together rather than assorting independently. This is called _____

Allele

Alternate forms of a gene/factor

Genotype

Combination of alleles in an organism

Phenotype

How an organism appears

Dominant

An allele which is expressed (masks the other allele)

Recessive

An allele which is present but remains unexpressed

Homozygous

Both alleles for a trait are the same

Heterozygous

The organism’s alleles for a trait are different

fundamental laws of heredity

developed in the mid 19th century by Gregor Mendel

Gregor Mendel

• an Australian monk

• He developed the fundamental laws of heredity

• Blended Concept of Inheritance vs Particulate Theory of Inheritance

True

Gregor Mendel developed the heredity principles without ANY scientific equipment - only his mind.

TRUE OR FALSE

True

• Mendel chose garden peas (Pisum sativum) as his subjects as they are easily grown and their pollination is easily controlled.

• He controlled pollination by manually moving pollen between plants

TRUE OR FALSE

Gregor Mendel

He developed True-breeding plants by self-pollination

True

Why Mendel Was Successful:

• Unbiased

• Selected good model organism

• Used pure breeds as parents

TRUE OR FALSE

True

Why Mendel Was Successful:

• Large sample size

• Quantitative analysis

• Controlled experiments

• Studied obvious trait

TRUE OR FALSE

True

MENDEL’S CONCLUSIONS

Genes do not blend together.

• The hereditary determinants, or genes, maintain their integrity from generation to generation.

• They do not blend together,

• they do not acquire characteristics in response to actions by an individual

TRUE OR FALSE

True

MENDEL’S CONCLUSIONS

Peas have two versions, or alleles, of each gene.

• This is also true for many other organisms.

TRUE OR FALSE

True

MENDEL’S CONCLUSIONS

Each gamete contains one allele of each gene.

• Pairs of alleles segregate during the formation of gametes

TRUE OR FALSE

True

MENDEL’S CONCLUSIONS

Males and females contribute equally to the genotype of their offspring.

• When gametes fuse, offspring acquire a total of two alleles— one from each parent

TRUE OR FALSE

True

MENDEL’S CONCLUSIONS

Some alleles are dominant to others.

• When a dominant and recessive allele for the same gene are found in the same individual, that individual exhibits the dominant phenotype

TRUE OR FALSE

Law of Segregation, Law of Independent Assortment

Laws of Inheritance (2)

Law of Segregation

A type of Law of Inheritance:

• Alleles occur in pairs and that in the formation of gametes, these segregate so that only one member of a pair goes into a particular gamete.

Law of Independent Assortment

A type of Law of Inheritance:

• based on dihybrid crosses where two genes are considered simultaneously

• alleles in different gene pairs separate cleanly from each other and randomly combine during gamete formatio

Punnett Squares

Genetic problems can be easily solved using a tool called a _____

Punnett Squares

Tool for calculating genetic probabilities

Dihybrid crosses

These are made when 2 independent gene pairs are analyzed at the same time

Walter Sutton

The person who stated that “chromosomes were the physical carriers of Mendel's alleles”

Linkage and crossing over

Why are the number of alleles which undergo independent assortment greater than the number of chromosomes of an organism?

sex chromosomes

All chromosomes are homologous except on

Hemophilia

Disorder of the blood where clotting does not occur properly due to a faulty protein.

Phenotypes are controlled by more than 1 allele.

TRUE OR FALSE

true

Incomplete Dominance

Some alleles for a gene are not completely dominant over the others.

TRUE OR FALSE

Human height

Continuous Variation

Give one example of trait that have a wide range of continuous values.

Gene interactions

Other factors of Gene mutation:

• Two gene pairs of different loci interact together for one phenotype

Environmental Effects

Other factors of Gene mutation:

• Sometimes genes will not be fully expressed owing to external factors.

• Example: Human height

Phenotype = Genotype x Environment

Formula of phenotype for gene mutation by environmental effects

Gregor Mendel

He experimented with pea plants, by crossing various stains and observing the characteristics of their offspring

True

When Gregor Mendel crossed these F1 plants, he would get offspring which produced round and wrinkled peas in a 3:1 ratio.

TRUE OR FALSE