1. BIOLOGY Unit 4 Notes: Reproduction & Karyotyping

2. (1) Types of Reproduction
SEXUAL
ASEXUAL
Requires 2 parent organisms.
Requires 1 parent organism.
Sperm + Egg fertilize one another to form a Zygote.
The single organism makes a copy of itself and divides.
The offspring are genetically unique from the parents, but contain a random combination of parental genes.
The offspring are genetically identical to the parent.
Used by humans, other animals and plants.
Used by yeast, sponges, and bacteria.
Pros  Produces genetically different babies, increasing the survival rate of the population.
Cons  Requires a lot of time and effort.
Pros  Extremely efficient.
Cons  If the parent has genetic defects / deficiencies, all of its offspring will also be “weak”.

4. (2) Types of Asexual Reproduction:
Binary Fission: The organism makes an identical copy of itself, divides and splits in two.
Budding: The parent organism develops a small bud off its side, which develops into an exact copy.

7. (3) Bacteria & Conjugation
Bacterial Conjugation: The process by which bacteria exchange extra DNA structures (called plasmids) which can increase resistance to antibiotics.
When Does This Happen In Us?
If you don’t finish a full round of antibiotics…
This allows a mix of weaker bacteria to survive, along with the more fit ones (with the plasmids).
Bacteria can then pass on their extra special DNA.
This makes more bacteria resistant to your medicine.
What is the Long Term Concern?
Some wonder if our overuse of antibacterial body products and antibiotic medicines could be promoting the evolution of antibiotic-resistant bacteria.

10. (4) Karyotyping:
Purpose: To look at chromosome pairs to identify chromosomal-disorders.
Process:
Stain DNA.
Organize longest  shortest.
Organize by banding pattern.
Sex chromosomes at the end.
Look for too many, missing, shortened, or lengthened chromosomes.

11. (5) Chromosomes: Sex Chromosomes: “Normal” Numbers: Male = X and Y
Female = X and X
“Normal” Numbers:
23 pairs OR 46 total

14. (6) Down Syndrome: Chromosomes: Physical Characteristics:
Trisomy 21 = 3 chromosomes at #21
Total = 47 chromosomes
Physical Characteristics:
Round-Asian-Like Facial features, short stature, heart defects
Shorter lifespan
Prone to Alzheimer’s and leukemia

15. (7) Patau Syndrome: Chromosomes: Physical Characteristics:
Trisomy 13 = 3 chromosomes at #13
Total = 47 chromosomes
Physical Characteristics:
Eye, Brain and Circulatory defects
Cleft Palate
Death typical w/in months of birth

16. (8) Edward’s Syndrome: Chromosomes: Physical Characteristics:
Trisomy 18 = 3 chromosomes at #18
Total = 47 chromosomes
Physical Characteristics:
Every organ defected
Death w/in months after birth

17. (9) Klinefelter Syndrome:
Chromosomes:
XXY
Total = 47 chromosomes
Physical Characteristics:
Male sex organs, but underdeveloped + sterile
Other feminine body characteristics
Normal intelligence

18. (10) Turner’s Syndrome: Chromosomes: Physical Characteristics:
Only 1 X chromosome
Total = 45 chromosomes
Physical Characteristics:
Female
Do not mature sexually + are sterile
Short stature
Normal Intelligence
(Most die before birth)