Chapter 5

Notes Over Text

An organism is a collection of traits inherited from its parents.

____________ – is the passing of traits from parent to offspring.

____________ – is the study of heredity.

____________ – are different forms of a trait that genes may have.  Each sex cell has one allele for each trait.  Sometimes these alleles are expressed, and sometimes they are not.

____________ – is called the “Father of ____________ .” 

·        He was a monk in Austria during the 1800’s who studied science and math.

·        Starting in 1856, he worked for 8 years studying the characteristics of ____________ plants (____________ and ____________ of ____________ and ____________ , ____________ of plant, ____________ positions and color).  He cross-pollinated plants and observed the offspring’s characteristics.

____________ – received different information from each parent.

____________ – received the same information from each parent, and they will always produce the same traits in their offspring.

____________ traits – are forms of a trait that appear to dominate or mask another form of the same trait.

____________ traits – are forms of a trait that seem to disappear in a population.

____________ – is a branch of mathematics that helps you predict the chance that something will happen.

·        ____________ Square – is a tool that helps one predict results of crosses.

o       ____________ letters – are used in the square to represent dominant alleles.

o       ____________ letters – are used in the square to represent recessive alleles.

The Punnett Square shows the genotype possibilities of a cross.

____________ – is the physical trait that shows.

____________ – is the genetic makeup or code for a trait.

·        ____________ – are genotypes that have 2 alleles that are coding for the same trait.

·        ____________ – are genotypes that have 2 different alleles.

Mendel was lucky in his pick of characteristics and the pea plants that he worked with.  Many organisms and traits are not as clear-cut as the pea’s.  Many other characteristics of organisms deviate from Mendel’s results.

____________ – occurs when a phenotype is produced that is intermediate to those of the two homozygous parents.  (I.e.: 4 O’clock Flowers may be pink if a red and a white flower are crossed.)

____________ – occur when a trait is controlled by more than 2 alleles. (I.e.: the human blood type is controlled by three possible alleles – A, B, O)

____________ – occurs when more than one allele is expressed such as A and B in human blood types.

inherit____________ ance – group of gene pairs act together to produce a single trait combination of alleles produces a wide variety of phenotypes.

Examples: ____________ , ____________ , fingerprints, etc.

Not just humans (____________ production In chickens, grain color in ____________ , ____________ production in cows)

Your environment plays a role in how or if some genes are expressed. 

Chromosomal ____________ – may occur if the incorrect number of chromosomes is inherited.   This is usually fatal to the unborn fetus, or the baby may die shortly after birth.

For example, if an extra chromosome 21 is inherited, Down’s syndrome is the result.

Recessive Genetic disorders are caused by recessive genes.

For example, ____________  is caused by a recessive gene.  It causes thick mucus to be produced in lungs and the intestinal track – makes it hard to breath or digest food.

Sex of an organism is determined also by two alleles. 

–       female = ____________

–       male = ____________

Some genetic disorders are inherited with the X or Y sex chromosome.  This is called a ____________ gene.

____________ is an example of a gene found on x chromosome.

A ____________ color in cats is also an example.

More males are color blind because the recessive trait will not be masked by dominant (men don’t get another chance to get a dominant allele)

____________ is also sex linked.  This causes blood to not clot properly.

A female without the recessive disorder but with the gene is a ____________

____________ – is a tool for tracing traits in a family.

·        square = ____________

·        circle = ____________

·        half colored = ____________

·        all colored= ____________

·        empty = ____________  

____________ - changes the arrangement of DNA that makes up a gene in order to make medicines, cause cells to perform normal functions, improve crop production and quality, and give plants disease resistance.

1.     Recombinant DNA – is putting useful DNA into a bacteria cell.  This has been used to treat cancer and dwarfism.

2.     Gene Therapy – is putting useful DNA into a virus. This has been used to treat cancer and cystic fibrosis.

3.     Selective Breeding – is picking the best plants to breed for the next generation.