DNA Replication Process
- An enzyme moves in and splits DNA
- New nucleotides move in and pair up with the original strands
- This is a Semi-conservative Process, half of the DNA is new, half is conserved
What are the two types of genetic mutations?
- Base Pair Substitution - When base pairs flip (A+T becomes G+C)
- Frame Shift Mutation - A base is deleted or added ( CAT WHO become ATW HO)
How can DNA be amplified?
Polymerase Chain Reaction (PCR) Machine.
Gel Electrophoresis Process
- A restrictive enzyme cuts DNA into fragments which are placed in agarose gel and separated based on size or charge
- When settled they form a pattern which is your DNA finger print
What is Mitosis?
A form of asexual reproduction in which no genetic material is exchanged and all daughter cells are identical to parent cells. Mitosis occurs in all Stomatic cells (body cells).
What is the purpose of mitosis?
- Replacing cells
- New growth
- Regenerate damaged cells
What are the phases of the cell cycle in mitosis?
- Interphase, the longest phase, the cell prepares for mitosis, DNA and centrioles duplicate
- Prophase, nuclear membrane and nucleolus disappear, chromatin coil up
- Metaphase, chromatin line up in the middle, spindle fibres attach to the centromeres
- Anaphase, chromosomes are pulled apart, and centromeres split in half
- Telophase, pinching of cytoplasm, nuclear membrane and nucleolus, chromatids uncoil and become chromatin, spindle fibres disappear, 2 identical cells form each has 46 chromasomes.
What is Meiosis?
A form of sexual reproduction in which 2 parent cells are required to exchange genetic information, and all daughter cells look different. Occurs in reproductive organs.
What is the purpose of Meiosis?
- To receive half of your chromosomes
from each parent. - Haploid: half the number of chromosomes (23 or n)
- Diploid: total number of chromosomes (46 or 2n)
Phases of Meiosis?
- Interphase, same as mitosis
- Prophase I, homologous pairs pair up, and centromeres attach forming a tetrad, crossing over occurs
- Metaphase I, homologous pairs line up randomly
- Anaphase I, chromosomes separate
- Telophase I, DNA is replicated and needs a 2nd division
- Each process repeats until 4 varied cells are produced
What is Gametogenesis?
- The production of gametes
- Spermatogenesis, making of sperm, 4 sperm are produced from a germ cell called the Spermatogonium
- Oogenesis, making of eggs, 4 eggs are produced, 1 is dominant, 3 are polar bodies, produced from a Germ cell called the Oogonium.
What is a Karyotype?
An image or illustration of the chromosomes in a stomatic nucleus.
What are the 4 types of changes in chromosomes?
- Deletion
- Duplication
- Inversion
- Translocation
What is Non-Disjunction?
- When chromosomes fail to separate properly
What is Trisonomy?
- When a gamete contains an extra chromosome, Down Syndrome is an example of Trisonomy
Genotype definition
- Pair of alleles represented by 2 letters. Ex. Bb, TT, mm
Phenotype definition
- Characteristics of an organism
Homozygous definition
- Two identical alleles, BB, bb
Heterozygous definition
- Two non-identical alleles, Bb
Testcross definition
Crossing a subject using a known homozygous recessive organism
Who was Gregor Mendel?
- The father of genetics
- A monk who bred pea plants until he obtained a pure tall and short subject
What is Mendel’s Law of Dominance?
When an organism is a hybrid of contrasting traits only the the dominant trait will show (Bb)
What is Mendel’s Law of Segregation?
Factors that occur in pairs are separated in gamete formation and recombined at fertilization.
What is a Monohybrid Cross?
Crossing one pair of contrasting traits. (Bb x bb)
