science bio

• Female Reproductive System:

  • Stores and releases sex cells (ovum/egg cell)
• Parts of the Female Reproductive System:

  • Ovaries: produce, store, and release ovum; contain about 2 million unripe eggs in a lifetime; 1 egg develops each month and is released into the fallopian tube
  • Fallopian Tube: connects ovaries to the uterus; fingerlike fimbriae guide the egg; hair-like cilia help egg travel and fertilization occurs here
  • Uterus: hollow organ where fetus develops; cervix opens to vagina
  • Vagina: behind the urinary opening, rounded by the vulva
• Egg Cell or Ovum:

  • Largest cell in the body, about 0.1 millimeters
  • Corona Radiata: surrounds the egg and provides vital proteins
  • Zona Pellucida: outer membrane that helps sperm enter and prevents further sperm entry after fertilization
• Menstrual Cycle:

  • 28-day cycle preparing for pregnancy
  • Menstruation Phase (Day 0-5): unfertilized egg and uterine lining shed
  • Follicular Phase (Day 6-14): one egg matures, uterine lining thickens
  • Ovulation Day (Day 15): mature egg released
  • Luteal Phase (Day 15-28): corpus luteum releases progesterone to maintain uterine lining
• Male Reproductive System:

  • Produces male sex cells (sperm) and transports them to the female reproductive system
• Parts of the Male Reproductive System:

  • Testes: produce sperm
  • Epididymis: stores and matures sperm before passing to vas deferens
  • Vas/Ductus Deferens: excretory ducts of testes that run to the urethra
  • Urethra: tube along the penis
  • Prostate Gland: produces seminal fluid
  • Seminal Vesicles: produce fluid for semen
  • Penis: male sex organ
• Sperm Cell or Spermatozoon:

  • Male reproductive cells that unite with the ovum
  • Tail (Flagellum): provides movement
  • Middle Piece (Mitochondria): provides power
  • Head (Nucleus and Acrosome): contains chromosomes and digestive enzyme
• Fertilization:

  • Union of sperm and egg to form a zygote
  • Millions of sperms travel to fallopian tube, one fertilizes egg
  • Conception: time between fertilization and implantation
  • Implantation: fertilized egg attaches to the uterus lining
• How the Embryo Develops:

  • At 8 weeks, embryo becomes a fetus
  • Develops major organs, heart starts to beat, umbilical cord forms
• How the Fetus Develops:

  • From 1 ounce at 8 weeks to 7 pounds at birth
  • Develops arms, legs, head, hair, teeth, and grows in proportion
• Identical Twins:

  • Single egg fertilized and divides to produce twins
  • Share the same placenta
• Endocrine System:

  • System of glands secreting hormones
  • Maintains homeostasis and controls body development
• Function and Location of the 8 Endocrine Glands:

  • H hypothalamus, P pituitary Gland, A adrenal Glands, T thyroid, P parathyroid, P pancreas, T testes, O ovaries
• Route to the Brain:

  • Signals from receptors travel to spinal cord or brain
  • Brain receives and responds to maintain homeostasis
• Negative Feedback:

  • Control mechanism to maintain stability in the body
  • Examples: Blood Glucose Regulation, Body Temperature Maintenance
• Positive Feedback:

  • Increases the rate of processes
  • Examples: Cuts and Bruises, Childbirth
• Proteins are macromolecule polymers made of a long chain of amino acids
• Peptide bonds hold together these long chains of amino acids hence proteins are called polypeptides
• 7 Major Classes of Protein:

  • Structural: spider silk, human hair, fiber in tendons and ligaments
  • Contractile: provides muscular instrument
  • Storage: ovalbumin (egg white)
  • Defensive: antibodies
  • Transport: hemoglobin
  • Signal: hormones coordinating body activity
  • Enzymes: serve as a chemical catalyst
• 3 Major Functions of Protein:

  • Hormones regulate physiological processes
  • Blood clotting process and transport of oxygen in the blood
  • Act as channels, carriers, and receptor molecules in the cell membrane
• There are 20 amino acids needed by the body, 11 are non-essential and 9 are essential
• Deoxyribonucleic Acid (DNA) is composed of two polynucleotide chains that coil around each other to form a double-helix structure
• DNA Replication is the process of producing two identical replicas of DNA from one original DNA molecule
• 3 Kinds of RNA in Protein Synthesis:

  • Messenger RNA (mRNA)
  • Ribosomal RNA (rRNA)
  • Transfer RNA (tRNA)
• The DNA is found inside the nucleus and must be transported to the ribosomes in the cytoplasm for protein synthesis.
• Mutations are alterations in the nucleotide sequence of the genome of an organism, virus, or extra-chromosomal DNA
• Mutations Occurring in Sex Cells:

  • Somatic Mutation: not passed to offspring
  • Germinal Mutation: passed on to offspring
• Genetic Disorders:

  • Sickle Cell Anemia
  • Tay-Sachs
  • Phenylketonuria (PKU)
  • Cystic Fibrosis
• Causes of Mutation:

  • Smoking
  • Old age at conception
  • Chemotherapy and External Influences
• Evidence of Evolution:

  • Embryology Studies
  • Homologous Structure
  • Vestigial Structure
  • Genetics
  • Fossils
• Factors that Can Lead to Evolution:

  • Gene Flow
  • Genetic Drift
  • Mutation
  • Sexual Selection
• Entropy is a measure of energy dispersal or spread at a specific temperature
• Abiotic Factors Needed by Organisms for Survival:

  • Water
  • Temperature
  • Light
  • Atmospheric Pressure
  • Chemical Components
• Adaptation for Survival:

  • Structural Adaptation
  • Prehistoric Adaptation
  • Adaptations for Unfavorable Conditions
• Levels of Biodiversity:

  • Species Diversity
  • Genetic Diversity
  • Ecosystem Diversity
• Relationship Between Population Growth and Carrying Capacity to Minimize Human Impact on the Environment
• Impact of Human Activities on Biodiversity Loss:

  • Global Warming
  • Population Growth
  • Pollution
  • Habitat Destruction
• Opportunities to Avoid or Minimize Negative Environmental Impact:

  • Consideration of environmental factors in decision-making
  • Reducing energy consumption and using renewable energy sources
  • Promote 3R’s: Reduce, reuse, recycle
• • DNA is made up of molecules called nucleotides – its monomer.
  • Each nucleotide contains:
  • Phosphate group
  • Sugar group
  • Nitrogen bases
  • There are four types of nitrogen bases:
  • Adenine
  • Thymine
  • Guanine
  • Cytosine
  • The order of these bases is what determines dna's instructions, or the genetic code.
• DNA Polymerase is a protein enzyme responsible for the bonding of nucleotides