BioMastery

Understanding Global Climate Change and the Greenhouse Effect What's the Difference Between Weather and Climate? Weather is the current condition of the atmosphere—temperature, rain, wind, and so on— right now . Climate refers to long-term patterns and averages of weather in a region—over decades or centuries . In short, weather is what’s happening today, climate is the big picture over time. The Greenhouse Effect: Nature's Thermal Blanket Our Earth is wrapped in an atmosphere made mostly of nitrogen and oxygen , but a small group of gases called greenhouse gases play an outsized role in maintaining Earth’s temperature. Here’s what happens: Solar radiation from the Sun enters Earth's atmosphere. Some of it is absorbed by the Earth’s surface, warming the planet. Some of the heat is reflected back toward space. Greenhouse gases trap some of this outgoing heat—just like a greenhouse traps warmth inside. That’s the greenhouse effect —and it...

Producers vs. Consumers 1. Autotrophs Also called primary producers . Make their own food through photosynthesis (e.g., plants, algae). They form the base of the energy pyramid and food web. 2. Heterotrophs Rely on consuming other organisms for food. Includes various consumer categories: Types of Heterotrophs: Carnivore – eats animals (e.g., hawks, lions). Herbivore – eats plants (e.g., rabbits). Omnivore – eats both plants and animals. Scavenger – feeds on dead animals (leftovers). Decomposer – fungi or bacteria that break down dead organisms. Detritivore – animals (like worms) that feed on decaying organic matter. Trophic Pyramids and Energy Flow Trophic Pyramid Structure: Represents how energy moves through an ecosystem. Each level passes on only 10% of energy to the next level; most is lost as heat or used for metabolic processes (like staying warm or moving). Example Pyramid: Primary Producers (Autotrophs) → 10,000 calories P...

The Human Immune System: Your Body's Defense Team Introduction The Three Lines of Immune Defense 1st Line of Defense – Physical Barriers (Non-Specific) These are the basic protections that prevent invaders from entering your body in the first place: Skin – acts as a tough outer shield Hair – especially in nostrils, helps trap particles Mucous – traps dust, microbes, and other particles Tears – wash away irritants and contain enzymes that kill bacteria 2nd Line of Defense – Internal Non-Specific Response When something gets past the skin, your body activates this backup team: Neutrophils – white blood cells that engulf invaders Pus – dead white blood cells and pathogens Fever – raises your body temperature to kill invaders Swelling (inflammation) – triggered by mast cells releasing histamines , increasing blood flow to the site of infection or injury Macrophages and the Shift to Specific Defense Once your body realizes the invader isn’t...

The Female Reproductive System and Ovarian Cycle Major Structures and Their Functions Fallopian Tubes Transports eggs from the ovary to the uterus. Site of fertilization – where sperm and egg usually meet! Fimbriae Finger-like projections that sweep the egg into the fallopian tube after ovulation. Ovaries Site of egg development and hormone production (estrogen & progesterone). Uterus Where a fertilized egg implants and grows. Inner lining ( endometrium ) sheds during menstruation if no pregnancy occurs. Myometrium : muscular wall that contracts during birth. Cervix Narrow "gateway" between uterus and vagina. Acts as a barrier and also helps guide sperm during ovulation. Vaginal Canal Path for sperm entry, menstruation exit, and childbirth. The Ovarian Cycle The ovarian cycle typically lasts around 28 days and includes 3 main phases : 1. Follicular Phase (Day 1–14) Begins with menstruation (she...

Understanding the Male Reproductive System Main Structures of the Male Reproductive System: 1. Testes The powerhouse of sperm production. Also responsible for testosterone production, the hormone that fuels male development and reproductive function. 2. Scrotum A sac that holds and protects the testes . Keeps sperm at the ideal temperature— a few degrees below body temperature . Fun fact: it contracts when cold to bring the testes closer to the body and expands when warm to keep things cool. 3. Epididymis Sperm is stored here after it's produced. It’s the maturation site —sperm gains mobility and the ability to fertilize an egg. The Path of Sperm: 4. Vas Deferens This tube transports mature sperm from the epididymis to the urethra during ejaculation. 5. Seminal Vesicle Produces seminal fluid , rich in sugar and nutrients. This fluid mixes with sperm to form semen. 6. Prostate Gland Adds additional supportive fluids that help protect sperm ...

The Endocrine System What Are Hormones? Hormones are powerful chemical messengers produced by glands in your body. They're released into the bloodstream and travel throughout the body to target cells that have the specific receptors to respond to them. So, despite floating freely in your system, hormones only affect target cells —like having a key that only fits certain locks. Major Endocrine Glands and Their Functions: Pituitary Gland : The “master gland” controlling other glands. Pineal Gland : Produces melatonin, regulating sleep. Thyroid Gland : Controls metabolism via T3 and T4. Parathyroid Glands : Regulate calcium levels in blood. Adrenal Glands : Produce adrenaline for stress responses. Pancreas : Manages blood sugar with insulin and glucagon. Ovaries/Testes : Control reproduction and sex hormones. Gland Hormone Target Tissue Principal Actions Hypothalamus Releasing and inhibiting hormones Anterior lobe of pituitary gland Stimulates or inhibits...