Biology Chapter on Pregnancy and Chemical Bonds

Seven Characteristics of Life

• Movement, respiration, sensitivity, growth, reproduction, exertion, nutrition are the seven characteristics of life.

Mitosis

• Cell division where one cell divides into two cells.
• Occurs during reproduction, growth, and healing.

Meiosis

• Occurs during reproduction.
• The step before mitosis.
• Results in cells with 23 chromosomes (before sperm and egg unite).

Female Reproductive System

• Ovary: Produces egg cells and estrogen.
• Fallopian tube: Fertilization occurs here, then the fertilized egg is implanted, in the uterus.
• Uterus: Nurtures the developing egg into a fetus.
• Cervix: Opening to the vagina, plays a role in childbirth.
• Vagina: Where the baby exits and sperm enters.
• Hormones: Estrogen and progesterone.

Male Reproductive System

• Testes: Produce sperm and testosterone.
• Epididymis: Stores mature sperm.
• Vas deferens: Transports sperm and mixes it with fluid to form semen.
• Urethra: Tube through which semen passes out.
• Penis: Delivers semen.
• Hormone: Testosterone (influences facial hair, voice).

Sex Chromosome Inheritance

• Egg carries X chromosome.
• Sperm carries X or Y chromosome.
• Determines the sex of the offspring.

Menstrual Cycle

• Menstruation (Day 1-5): Uterus lining sheds.
• Follicular phase (Day 5-14):
  • Follicles (sacs with immature eggs) develop in ovaries.
  • FSH (Follicle-stimulating hormone) stimulates egg maturation.
  • Estrogen levels rise.
  • Many follicles develop, but only one reaches maturity.
  • Ovulation occurs (middle of cycle).
• Ovulation (Day 14): The mature egg is released.
• Luteal phase (Day 15-28):
  • If fertilized, pregnancy develops.
  • If not fertilized, the cycle repeats.
  • Progesterone levels rise.

Hormones in the Menstrual Cycle

• FSH rises first to stimulate estrogen development, then estrogen triggers the decrease of FSH.
• LH rises mid-cycle for ovulation.
• Progesterone rises after if fertilization does not occurs the cycle continues.

Fertilization

• Egg released from ovary, travels to fallopian tube.
• Meiosis occurs.
• Mitosis (cell division) begins.
• Egg develops into a zygote, then an embryo.
• Embryo implants in the uterine lining and grows.

Pregnancy Stages

• First trimester (Weeks 1-13):
  • Placenta grows.
  • Heart, liver, brain, fingers, and toes develop.
  • Sex organs differentiate.
• Second trimester (Weeks 13-28):
  • Bones and joints form.
  • Muscles (strength and movement).
  • Triple increase in size.
  • Rapid brain growth.
  • Hearing and breathing develop.
• Third trimester (Weeks 28-40):
  • Response to light and sound.
  • Lungs mature (fully functional).
  • Bones harden.
  • Eyes can open and close.
  • Dreaming ability develops.

Stages of Labor

• Stage 1: Dilation (Longest)
  • Contractions begin and continue until the cervix dilates fully.
  • Early phase: Mild, irregular, shorter contractions.
  • Active phase: Increasing pain, quicker contractions, more substantial opening of cervix.
  • Transitional phase: Cervix is fully dilated.
• Stage 2: Birth: Duration of 20 minutes to 2 hours.
• Stage 3: Placental Delivery: After birth, contractions to remove the placenta.

Twins

• Fraternal (Dizygotic): Two separate eggs fertilized by two separate sperm.
• Identical (Monozygotic): A single fertilized egg splits into two embryos.

Sperm Cell

• Head: Acrosome (enzymes for egg penetration), nucleus (DNA).
• Neck: Mitochondria (energy).
• Tail: Mobility.

STIs (Sexually Transmitted Infections)

• Caused by bacteria, viruses, or parasites.
• Examples: Chlamydia, gonorrhea, syphilis, HIV, HPV, herpes, trichomoniasis.
• Treatment varies by type of infection.
• AIDS caused by HIV.

Human Development Stages

• Infancy (Birth-2 years): Motor skills, language, teeth.
• Childhood (2-Puberty): Growth, language, coordination.
• Adolescence (Puberty-Adulthood): Reproductive maturity.
• Adulthood (Early, middle, late): Aging.

Immune System

• External defenses: Skin, mucus, cilia, tears, saliva, stomach acid, normal flora.
• Internal defenses: White blood cells, antibodies, inflammation, fever, memory cells.
  • Types of white blood cells:
    • Macrophages (engulf and digest pathogens)
    • Killer T-cells (attack infected body cells)
    • Helper T-cells (activate other immune cells)
    • B-cells (produce antibodies)
  • Pathogen: Harmful microorganism.
  • Antigen: Foreign substance recognized by the immune system.
  • Antibody: Target and destroy antigens.
• Active vs. Passive immunity: Difference in how antibodies are produced (memory cells associated with active).

Atomic Theory

• Dalton: Matter is made of atoms; indivisible.
• Thompson: Positive sphere with electrons embedded.
• Rutherford: Dense nucleus, with electrons orbiting.
• Bohr: Electrons orbit in fixed paths.
• Modern: Electrons in electron cloud, neutrons in the nucleus.

Chemistry - Periodic Table

• Atomic number: Number of protons.
• Atomic mass: Number of protons and neutrons.
• Group: Valence electrons.
• Period: Number of electron shells.
• Metals, nonmetals, metalloids.
• Ionic bonds: Transfer of electrons.
• Covalent bonds: Sharing of electrons.
• Molecule: Group of atoms held together by bonds.
• Metallic bonds: Overlapping electron shells.

Chemical Formulas and Ions

• Cations (positive ions) and anions (negative ions).
• Monoatomic and polyatomic ions.
• Naming acids (using rules for monoatomic and polyatomic anions). Acids are identified using a root name with either an 'ic' or 'ous' ending followed by the word, acid.

Test your knowledge on key biological processes that occur during the first trimester of pregnancy, along with fundamental chemistry concepts such as atomic structures and bonding. This quiz will challenge your understanding of twins, hormones, and properties of elements. Ideal for students studying biology and chemistry together.