SC.L.16.1 MENDEL’S LAWS OF SEGREGATION AND INDEPENDENT ASSORTMENT TO ANALYZE PATTERNS OF INHERITANCE.

Mendel’s Law of segregation states than when an organism produces gametes, its two alleles for a trait separate and go into different gametes (sex cells). In this way when gametes from two parents join to produce a new organism, the offspring receives one allele from each parent.

A diagram called a Punnett square is useful for finding the results of a simple genetic cross.The parents alleles are writtenacross the top and side of the square. Combining these allelesgives the possible genotypes of the offspring, as shown below.

R: Dominant allele produces round seedsr: Recessive allele produces wrinkled seedsHomozygous (pure) two alleles with the same genetic information RR or rrHeterozygous (hybrid) two alleles with different information Rr

Two round seeded plant produced a wrinkled seeded plant because the plant

received two recessive alleles for wrinkled seed.

LAW OF INDEPENDENT ASSORTMENTMendel’s Law of independent

assortment statesthat when gametes are formed, the

genes fordifferent traits are inherited separately. In metaphase I, the homologous

chromosomes line up along the center of the cell in a

randomfashion

SC.L.16.3 DESCRIBE THE BASIC PROCESS OF DNA REPLICATION AND HOW IT RELATES TO THE TRANSMISSION AND CONSERVATION OF THE GENETIC INFORMATION

DNA AnimationDNA replication begins at specific point in the DNA molecule calledthe origin of replication site.

The enzyme HELICASE unwinds, and separates a portion of the DNA moleculeSingle strand binding proteins react with and stabilize the separated,single stranded sections of the DNA molecule.

An enzyme called primase assembles an RNA primer at the origin of Replication site. The RNA primer consists of a short sequence of nucleotides complementary to a small, initial section of DNA strand being prepared for replication.

DNA polymerase adds DNA nucleotides to the RNA primer and thus begin the process of constructing a new complementary strand of DNA.Later the RNA primer is enzymatic ally removed and replaced with an appropriate sequence of DNA nucleotides.

Because the two complementary strands of the DNA molecule are oriented in opposite direction, and the DNA polymerase can accommodate replication in only one direction, two different mechanisms for copying the strands of DNA are employed.

One strand is replicated continuously towards the unwinding, separating portion of the original DNA molecule; while the other strand is replicated discontinuously in the opposite direction with the formation of a series of short DNA segments called Okazaki fragments. Each Okazaki fragment requires a separate RNA primer.

As the Okazaki fragments are synthesized, the RNA primer is enzymatic ally removed and replaced with the appropriate sequences o DNA nucleotides.

The individual Okazaki fragments are then bonded together into a continuous complementary strand by a DNA ligase, which seals the gaps between the segments.

DNA replication results in two identical daughter molecules each consisting of one old (original) strand and one newly-synthesized strand.

SUMMARY1. Separation by Helicase2. RNA primer binds to template3. DNA polymerase brings DNA nucleotides4. DNA ligase seals the gaps between the Okazaki

fragments.

DNA STRUCTURE

PROTEIN SYNTHESISAn individual’s traits such as hair color and eye color, are determined by proteins. Proteins are made up of chains of aminoacids. DNA codes for 20 amino acids. How these amino acidscombine determines the shape and purpose of the proteins theyform.PROTEIN SYNTHESIS ANIMATION 1PROTEIN SYNTHESIS ANIMATION 2The information in an organism DNA is used to make proteins. Iftwo of the base pairs are switched a mutation occurs and a different protein is made.

SC.L16.17 COMPARE AND CONTRAST MITOSIS AND MEIOSIS

Feature Meiosis MitosisDefinition A type of cellular

reproduction in which the number of chromosomes are reduced by half.

A process of asexual reproduction in which the cell divides in two producing a replica, (the number of chromosomes stays the same)

Function Sexual reproduction Cellular Reproduction & general growth and repair of the body

Type of cell produced Sex cell known as gametes(egg and sperm)

Body cell (blood cells, epithelial, muscle, nerve cells etc)

Type of Reproduction Sexual Asexual

Daughter cells are Genetically

Different from parent cell(shows genetic diversity)

Identical to parent cell(exact replica of parent cell)

CONTINUATION….Feature Meiosis MitosisCrossing over Yes, mixing of

chromosomes can occur

No, crossing over cannot occur

Paring of homologous chromosomes

Yes, then homologous chromosomes separate and produce 4 haploid daughter cells.

No

Beginning cell Diploid cell Diploid cell Number of cells produced

4 2

Number of chromosomes

Half the original cell Same as original cell

End product 4 Haploid cells(the cells show genetic diversity)

2 diploid cells(an exact replica of the parent cell)

II II

IIIIIII I

SIMILARITIES BETWEEN MITOSIS AND MEIOSIS

Both are forms of cell division. Both begging with diploid cells. Both occur within the nucleus of the cell. Both go through the same steps known

as Prophase, Metaphase, Anaphase and Telophase.

Both have in common cytokines is (The cytoplasm divides)

SC.16.1 MENDEL’S LAWS OF SEGREGATION AND INDEPENDENT ASSORTMENT TO ANALYZE PATTERNS OF INHERITANCE.

Mendel’s Law of segregation states than when an organism produces gametes, its two alleles for a trait separate and go into different gametes (sex cells). In this way when gametes from two parents join to produce a new organism, the offspring receives one allele from each parent.

A diagram called a Punnett square is useful for finding the results of a simple genetic cross.The parents alleles are writtenacross the top and side of the square. Combining these allelesgives the possible genotypes of the offspring, as shown below.

R: Dominant allele produces round seedsr: Recessive allele produces wrinkled seedsHomozygous (pure) two alleles with the same genetic information RR or rrHeterozygous (hybrid) two alleles with different information Rr

Two round seeded plant produced a wrinkled seeded plant because the plant

received two recessive alleles for wrinkled seed.

LAW OF INDEPENDENT ASSORTMENTMendel’s Law of independent

assortment statesthat when gametes are formed, the

genes fordifferent traits are inherited separately. In metaphase I, the homologous

chromosomes line up along the center of the cell in a

randomfashion