Chap 11 - genetic notes

Página 1

Genes - Sections of DNA on a chromosome that

contain the instructions for making specific proteins for each characteristic

donated by the parent organism, and they control an organism’s form and

function.

Traits

– Characteristics that are passed on from parent to offspring (ex: eye

color and nose shape)

Alleles

are the different forms of a trait that a gene may have, and they may be

dominant or recessive.

Dominant

– Represented by capital letters (ex: R or D). This trait dominates a trait that

covers over, or dominated, another form of that trait. (“Hefty”)

Recessive

– Represented by lower case letters (ex: r or d). This trait is covered

over, or dominated, by another form of that trait and seems to disappear.

(“Wimpy”)

This trait seems to recede in the background in first-generation

offspring

Heterozygous

– An organism with two different alleles for a trait; also known as a

hybrid (ex: Hh or Tt)

Hybrid – Offspring that was given different genetic information

for a trait from each parent

Homozygous

– An organism with two of the same alleles for a trait; also known as a

purebred (ex: HH, hh, or TT, tt)

Purebred – Organism that always produces the same traits

generation after generation

Punnett

Squares – Punnett developed a square used to help predict results of the

offspring in Mendelian genetics, and the letters represent dominant and

recessive alleles.

Probability

– A branch of mathematics that helps predict the chance that an event or

something will occur (happen)

Genotype

– The genetic make-up of an organism and understanding what the letters

represent tells you a lot about the inheritance of a trait in an organism

(ex: cc - alleles for a homozygous recessive genetic disorder). An inherited combination of alleles.

Phenotype

– The way an organism looks and behaves as a result of its genotype; it’s

appearance (ex: cc – The organism would have Cystic Fibrosis)

Mendelian Genetics – Gregor Mendel is known as the

Father of Genetics because he was the first to do three things:

Trace

a single trait through multiple generations – Remember his pea plant

experiment:

The

two parent pea pod plants were: one green (dominant trait for color) and

one yellow (recessive trait for color)

The

first generation offspring had green color pea pods (dominant), and the

yellow color pea pods (recessive) seemed to disappear in the offspring.

He

collected seed from the first generation pea plants and raised a 2nd

generation which resulted in three green color pea pod plants and one

yellow color pea pod plants (the recessive trait reappearing)

Use

mathematics of probability in predicting possible offspring

Develop

the principles of here

Be able to devise a chart that explains:

Mitosis vs Meiosis

Probability

Calculations Formula:

P

(desired genotype) = # of offspring that have desired genotype (x100)

Total # of possible offspring

Study guide adapted from these resources

schools.paulding.k12.ga.us/.../2720/Unit

Study Guide.doc: http://r.search.yahoo.com/_ylt=A0LEV7j2DzRVgFQAHrgnnIlQ;_ylu=X3oDMTEzY2liam83BHNlYwNzcgRwb3MDNARjb2xvA2JmMQR2dGlkA1lIUzAwM18x/RV=2/RE=1429504119/RO=10/RU=http%3a%2f%2fschools.paulding.k12.ga.us%2fischooldistrict%2fmedia%2ffiles%2f2720%2fUnit%2520Study%2520Guide.doc/RK=0/RS=fWef26kDDMaCaTqZa4qipoHT.KM-