Chapter 5: Genetics

Lesson 1: Mendel & His Peas A characteristic that an organism can pass on to its offspring through its genes is called what? A TRAIT The passing of traits from parents to offspring is called what? HEREDITY

The scientific study of heredity is called what? FROM GREEK GENESIS, MEANS “ORIGIN” GENETICS The Father of Genetics, priest, student at the University of Vienna & teacher is who? GREGOR MENDEL

PUREBRED OR TRUE-BREED An organism that always produces offspring with the same form of a trait as the parent is what? PUREBRED OR TRUE-BREED

What do these people all have in common in relation to genetics? A WIDOW’S PEAK

What do these people have in common in relation to genetics? A CLEFT CHIN

Scientists call factors that control traits what? GENES Different forms of genes are called alleles, your body cells contain more than 60,000 genes!

An organism that has two different alleles for a trait; an organism that is heterozygous for a particular trait is called a what? A HYBRID Capital letter is the representative of the dominate gene & the lower case letter is the representative of the recessive gene. Bb

BB Bb bb Two Dominate genes, therefore the dominate gene is present. One dominate gene & one recessive gene, therefore the dominate gene is present over the recessive one. Two recessive genes, therefore the recessive gene is present.

An allele (gene) that is masked when a dominant allele is present is An allele (gene) whose trait always shows up in the organism when the allele is present is called what? DOMINANT GENE An allele (gene) that is masked when a dominant allele is present is called what? RECESSIVE GENE

Lesson 2: Understanding Inheritance A rod-shaped cellular structure made of condensed chromatin; contains DNA, which carries the genetic information that controls inherited characteristic such as eye color & blood-type is called what? You have 46 of them… 23 from each parent! CHROMOSOME

The different forms of a gene are called what? ALLELES

An organism’s ____________ is its physical appearance, or its visible traits; like eye color, having dark eyes or blue eyes. An organism’s ____________ is its genetic makeup, or allele combination; like BB, Bb or bb. PHENOTYPE GENOTYPE

HETEROZYGOUS OR HYBRID Having two identical alleles for a trait (BB or bb) means what? Having two different alleles for a trait (Bb) is called what? HOMOZYGOUS HETEROZYGOUS OR HYBRID

T t TT Tt tt A chart that shows all possible combinations of alleles (genes) that can result from a genetic cross is called what? A PUNNETT SQUARE MODEL

B b Bb Bb Bb Bb Geneticists use Punnett Squares to show all the possible outcomes of a genetic cross and to determine the probability of a particular outcome.

T t Tt tt Tt tt Bb bb b b B b

Male Chromosomes = Female Chromosomes = XY XX “The Male determines the sex of the offspring.” X Y XX XY XX XY 50% Probability for either sex

Is a chart or “family tree” that tracks which members of a family have a particular trait; it is a tool that geneticists use to trace the inheritance of traits in humans is called what? PEDIGREE

When the offspring’s phenotype is a combination of the parents’ phenotype is called what? INCOMPLETE DOMINANCE

A condition in which either neither of two alleles of a gene is dominate or recessive is called what? CO-DOMINANCE WHEN BOTH ALLELES CAN BE OBSERVED IN A PHENOTYPE, THIS TYPE OF INTERACTION IS CALLED CO-DOMINANCE

Some human traits are controlled by a single gene that has more than two genes (alleles) this is said to be called what? MULTIPLE ALLELES “Some human traits show a large number of phenotypes because the traits are controlled by many genes. The genes act together as a group to produce a single trait.”

POLYGENIC INHERITANCE This occurs when multiple genes determine the phenotype of a trait it is called what? POLYGENIC INHERITANCE EYE COLOR, WEIGHT & SKIN COLOR ARE EXAMPLES OF POLYGENIC INHERITANCE

Lesson 3: DNA & Genetics Is a molecule made of a nitrogen base, a sugar and a phosphate group which is called what? NUCLEOTIDE

The process of copying a DNA molecule to make another DNA molecule is called what? REPLICATION

______ plays an important role in the production of proteins & found in cytoplasm & the nucleus; there are three types. ______ is the genetic matter that carries information about an organism that is passed from parent to offspring. It also directs all the cells functions. RNA DNA

Nitrogen Bases: Adenine (A) can only pair with Thymine (T) & Cytosine (C) can only pair with Guanine (G) & vice versa.

The process of making mRNA from DNA is called what? TRANSCRIPTION The process of making a protein from RNA is called what? TRANSLATION

FROM LATIN MUTARE, MEANS “TO CHANGE” Any unexpected change that occurs in a gene or chromosome is called what? MUTATION A characteristic that helps an organism survive in its environment or reproduce is called what? FROM LATIN MUTARE, MEANS “TO CHANGE” ADAPTION

The Most Common Mutations in Humans are… 1. BALDNESS (MORE COMMON IN MEN) 2. PIMPLES 3. HIGH FERTILITY (MORE COMMON IN WOMEN) 4. COLOR BLINDNESS (MORE COMMON IN MEN) 5. LACTOSE INTOLERANCE

Seven Common Genetic Disorders are… CYSTIC FIBROSIS SICKLE-CELL DISEASE HEMOPHILIA DOWN SYNDROME PHENYLKETONURIA (PKU) WILLIAMS SYNDROME BREAST & OVARIAN CANCER

CYSTIC FIBROSIS HEMOPHILIA Is where the body produces abnormally thick mucus in the lungs & intestines; making it hard to breath. CYSTIC FIBROSIS Is where a person’s blood clots very slowly or not at all; a person can bleed to death from relatively small wounds. HEMOPHILIA

RYAN CLARK OF THE PITTSBURGH STEELERS HAS THIS DISEASE Is where it affects the blood and the production of hemoglobin; suffer from lack of oxygen, pain & weakness. SICKLE-CELL DISEASE RYAN CLARK OF THE PITTSBURGH STEELERS HAS THIS DISEASE

Is where a person’s cells have an extra copy of chromosomes 21; there is a distinct physical appearance, some have a certain degree of mental disability; along with heart defects. DOWN SYNDROME

PHENYLKETONURIA (PKU) People with defective PAH genes cannot break down the amino acid phenylalanine. If phenylalanine builds up in the blood, it poisons nerve cells. If untreated can lead to mental disabilities & seizure. PHENYLKETONURIA (PKU)

People with this syndrome are missing part of chromosome 7, including the elastin gene. The protein made from the elastin gene makes blood vessels strong & stretchy. The most common symptoms are mental disability, heart defects & unusual facial features. WILLIAMS SYNDROME

BREAST CANCER OVARIAN CANCER A defect in BRCA1 and/or BRCA2 does not mean the person will have it, but with this defect have an increased risk of developing _________________ and/or ___________________. BREAST CANCER OVARIAN CANCER

Researchers are also trying to predict some genetic disorders Researchers are also trying to predict some genetic disorders. This process, called _______________, involves constructing Punnett Squares & Pedigree charts of parents genes. GENE THERAPY THIS IS DONE TO FIND OUT THE PROBABILITY IF THE OFFSPRING WILL HAVE A GENETIC DISORDER OR NOT.