Biology Unit 4 Notes: Reproduction & Karyotyping

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

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

14. • Chromosomes:
– 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
(6) Down Syndrome:

15. • Chromosomes:
– 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
(7) Patau Syndrome:

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

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

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