A priest who tended a monastery garden in Europe. A scientist
who experimented with heredity, traits, and genetics on his garden.
The father of genetics.
Slide 4
Mendel decided to cross plants with contrasting traits. He
started with two purebred plants in the parental generation. The
first filial generation all had one trait. In the second filial
generation the plants were allowed to self-pollinate resulting in a
mixture of traits.
Slide 5
Genes are factors that control a trait. Alleles are the
different forms of a gene. An organisms traits are controlled by
the alleles it inherits from its parents. Some alleles are
dominant, while other alleles are recessive. A dominant allele is
one whose trait always shows up in the organism when the allele is
present. A recessive allele is hidden whenever the dominant allele
is present. A hybrid organism has two different alleles for a
trait.
Slide 6
Through his experiments Mendel was able to conclude that
Genetic information controls the inheritance of traits. The female
parent contributes one factor while the male contributes another.
One factor in a pair can mask the other one.
Slide 7
Big Question
Slide 8
A number that describes how likely it is that an event will
occur. The laws of probability predict what is likely to occur, not
necessarily what will occur. Events occur independently from one
another.
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Big Question
Slide 10
The results of genetic crosses can be predicted by the laws of
probability.
Slide 11
Punnett Squares are charts that show all the possible
combinations of alleles that can result from a genetic cross. In a
genetic cross, the allele that each parent will pass on to its
offspring is based on probability. You can use a Punnett square to
predict probabilities.
Slide 12
An organisms phenotype is its physical appearance, or visible
traits. An organisms genotype is its genetic makeup, or allele
combinations. An organism that has two identical alleles for a
trait is said to be homozygous for that trait. An organism that has
two different alleles for a trait is heterozygous for that
trait.
Slide 13
In codominance, the alleles are neither dominant nor recessive.
As a result, both alleles are expressed in the offspring.
Slide 14
Big Question
Slide 15
To one another because genes are carried from parents to
offspring on chromosomes.
Slide 16
Sex cells only have half the number of chromosomes that the
bodys cells have. When a sperm cell and an egg cell join during
fertilization the fertilized egg has 24 chromosomes resulting from
the 12 chromosomes from each parent.
Slide 17
Meiosis is the process by which the number of chromosomes is
reduced by half to form sex cells. During Meiosis, the chromosome
pairs separate and are distributed to two different cells. The
resulting sex cells have only half as many chromosomes as the other
cells in the organism.
Slide 18
Big Question
Slide 19
Controlling the production of proteins which determine the
traits of an organism.
Slide 20
Chromosomes are composed mostly of DNA. A gene is a section of
a DNA molecule that contains the information to code for one
specific protein. A gene is made up of a series of bases in a row.
Each gene is located at a specific place on a chromosome. The order
of the nitrogen bases along a gene forms a genetic code that
specifies what type of protein will be produced.
Slide 21
The production of proteins is called protein synthesis. During
protein synthesis, the cell uses information from a gene on a
chromosome to produce a specific protein. mRNA brings DNA from the
nucleus into the cytoplasm. RNA has uracil instead of thymine as a
nitrogen base and has a different sugar. tRNA carries amino acids
to the ribosome and adds them to the growing protein.
Slide 22
A mutation is any change in a gene or chromosome. Mutations can
cause a cell to produce an incorrect protein during protein
synthesis. As a result, the organisms trait, or phenotype, may be
different from what it normally would have been. Mutations can be
either harmful or helpful and cause genetic variety.
Slide 23
Chapter 5
Slide 24
Big Question
Slide 25
That some human traits are controlled by single genes with two
alleles, and others by single genes with multiple alleles. Still
other traits are controlled by many genes that act together.
Slide 26
A number of human traits are controlled by a single gene with
one dominant allele and one recessive allele. These human traits
have two distinctly different phenotypes, or physical
appearances.
Slide 27
Genes like this are said to have multiple alleles three or more
forms of a gene that code for a single trait.
Slide 28
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.
Slide 29
The sex chromosomes carry genes that determine whether a person
is male or female. They also carry genes that determine other
traits. Girls have the two sex chromosomes called X chromosomes.
Boys have one X chromosome and one Y chromosome.
Slide 30
The genes for some human traits are carried on the sex
chromosome. These are called sex-linked genes. An example of a
sex-linked gene is the trait of red-green colorblindness.
Slide 31
Many of a persons characteristics are determined by an
interaction between genes and the environment.
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Big Question
Slide 33
The mutations in the DNA of genes. Changes in the structure of
genes Changes in the number of chromosomes. Some examples are:
Cystic fibrosis Sickle-cell disease Hemophilia Down syndrome
Slide 34
Doctors use tools such as karyotypes to help diagnose genetic
disorders. People with genetic disorders are helped through medical
care, education, job training and other methods. A karyotype is a
picture of all the chromosomes in a cell. Genetic counselling helps
couples understand their chances of having a child with a
particular genetic disorder.
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Big Question
Slide 36
Selective breeding, cloning, and genetic engineering. Selective
breeding is the process of selective organisms with desired traits
to be parents of the next generation. Inbreeding involves crossing
two individuals that have similar characteristics. Hybridization
breeders cross two genetically different individuals. A clone is an
organism that has exactly the same genes as the organism from which
it was produced.
Slide 37
Genetic engineering is a process when genes from one organism
are transferred into the DNA of another organism. In bacteria In
other organisms In gene therapy In genetic engineering