GENETICS

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GENETICS
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Asexual Reproduction

• Creation of genetically identical offspring from
  one parent

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Binary Fission

• A single celled organism splits into 2 equal
  parts
• Occurs in prokaryotes only (bacteria, yeast,
• some algae)

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Mitosis (Eukaryotes)

• Budding small projections grow on surface of
  parent and forms new organism.

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Mitosis cont (Eukaryotes)

• Vegetative Propagation
• stem of parent grows into a new organism
• Fragmentation parent splits into pieces that
  can each grown into a new organism

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Advantages to species(to reproduce asexually)

• Doesnt rely on outside forces( ex pollen
  relies on water and wind)
• Rapid
• More efficient (successful)

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Disadvantages to species(to reproduce asexually)

• All organisms respond same way to environment b/c
  they are just alike
• Organisms may lack the ability to adapt in order
  to survive changing conditions
• (Ex I Am Legend)

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ASEXUAL REPRODUCTION SEXUAL REPRODUCTION
Requires one parent Requires 2 parents
Mostly in prokaryotes Mostly in eukaryotes
Offspring are identical to parent Offspring are different than parent
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C. Sexual Reproduction

1. Sexual reproduction is the fusion of 2 gametes
   that results in offspring that are a genetic
   mixture of both parents.
2. Fertilization is the fusion of egg and sperm.

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CHROMOSOMES MEIOSIS
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EQ Why is there not anyone quite lA. Types of
Cells in Your Body

• Somatic cells body cells (make up body tissues
  and organs)
• Germ cells cells in your reproductive organs
  that make gametes (in ovaries and testes)
• Gametes sex cells (female eggs or ova///males
  sperm)
• Gametes have DNA that is passed to offspring

Egg Cell

Somatic cell (muscle)
Sperm cells
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B. Chromosomes

• Every species has a certain number of chromosomes
  per cell (the number is not related to
  complexity).
• Your body cells have 23 pairs of chromosomes.
• Chromosome pairs 1-22 are autosomes.
• Pair 23 is sex chromosomes, X and Y, that
  determine gender in mammals.
• Homologous chromosomes are 2 chromosomes, 1 from
  Mom and 1 from Dad, that have the same length
  and appearance.
• Scientists have arranged the 23 homologous pairs
  from largest to smallest.

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D. Diploid and Haploid Cells

• Diploid cells are your body cells.
• 2 copies of each chromosome (1 from Mom and 1
  from Dad)
• 2n
• Human Diploid is 46.

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• Haploid cells are the gametes (egg and sperm)
  
• 1 copy of every chromosome
• 1n
• Haploid number for humans is 23.
• Gametes have 22 autosomes and 1 sex chromosome.

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E. Meiosis

• Meiosis is the formation of gametes.
• Meiosis reduces chromosome number and creates
  genetic diversity.
• It divides diploid cells into haploid cells.
• Gametogenesis is the production of gametes.
• Spermatogenesis is the formation of sperm.
• Sperm is much smaller than eggs.
• 4 are produced each division.
• Produced from puberty until death
• Oogenesis is the formation of eggs. (ova)
• 1 egg and 3 polar bodies are produced during each
  division.
• All eggs are present at birth.

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F. MEIOSIS vs MITOSIS

• MEIOSIS

• MITOSIS

• Meiosis is the formation of gametes.
• Form of sexual reproduction.
• Produces 4 haploid cells
• (23 chromosomes).
• Produces genetically unique cells
• Occurs only at certain times of an organisms
  life cycle

1. 1. Mitosis is the formation of body cells.
2. Form of asexual reproduction.
3. Produces 2 diploid cells (46 chromosomes)
4. Produces genetically identical cells
5. Takes place throughout life

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Mendel Heredity
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A. Basics of Genetics

• GENETICS the study of heredity
• HEREDITY passing of traits from parents to
  offspring.
• Traits inherited characteristics
• Gregor Mendel
• Father of Genetics
• He worked with pea plants to see how traits were
  passed from one generation to the next.
• Mendels Conclusions
• Traits inherited as discrete units.
• Law of Segregation Organisms inherit 2 copies
  of each gene, but donate only one copy to each
  gamete.

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B. Traits, Genes, Alleles

• A gene is a specific region of DNA that codes for
  a particular protein.
• The same gene can have many different versions.
• Alleles are different forms of a gene.
• Ex-yellow or green , round or wrinkled
• Your cells have 2 sets of alleles for each trait
  (1 from each parent)
• Alleles are represented by letters. (AA, Aa, aa)
• Types of alleles
• Homozygous (pure) alleles are the same (AA or
  aa)
• Heterozygous (hybrid) alleles are different (Aa)

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4. Types of Alleles

• Homozygous

• Alleles are the same
• (AA or aa)
• Alleles are different.
• (Aa)

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5. Genes influence the development of traits.

• A genome is all of an organisms genetic
  material.
• A genotype is the genetic makeup of an organism.
  
• (Represented by AA, Aa, or aa)
• A phenotype is the physical appearance of an
  organism.
• (wrinkled or smooth)

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• A dominant allele is the allele that is always
  expressed if present.
• Always represented by a capital letter.
• A recessive allele is the allele thats only
  expressed when 2 copies are present.
• Always represented by a lowercase letter.
• Both homozygous dominant (AA) and heterozygous
  (Aa) genotypes yield a dominant phenotype