Population size changes as a result of four processes: Birth, death, immigration, and emigration. Nt = Population size at time t B = Number of births D = Number of deaths I = Number of immigrants E = Number of emigrants Individuals can move from one population to another, and population size can change from…
Human Population Growth: A Case Study Humans have a large impact on the global environment: Our population has grown explosively, along with our use of energy and resources. Human population reached 6.8 billion in 2010, more than double the number of people in 1960. Our use of energy and resources has grown even more rapidly.…
Distribution: Geographic area where individuals of a species occur. Abundance: Number of individuals in a given area. Ecologists try to understand what factors determine the distribution and abundance of species. Populations are dynamic—distribution and abundance can change over time and space. ***Understanding the factors that influence these dynamics helps us manage populations for harvest or…
An organism’s life history is a record of events relating to its growth, development, reproduction, and survival. Life history characteristics include: Age and size at sexual maturity. Amount and timing of reproduction. Survival and mortality rates. Life History Diversity Individuals within a species show variation in life-history traits due to genetic variation or environmental conditions.…
Humans have a large impact on the environment—pollution, land use change, climate change, etc. We are just beginning to realize that we also cause evolutionary change, and the consequences of this. Ecology and evolution are strongly interconnected. What Is Evolution? Evolution can be viewed as genetic change over time or as a process of descent…
The physical environment influences an organism’s ecological success in two ways: Availability of energy and resources—impacts growth and reproduction. Extreme conditions can exceed tolerance limits and impact survival. Energy supply can influence an organism’s ability to tolerate environmental extremes. The actual geographic distribution of a species is often lower than potential distribution due to other…
Introduction: The purpose of this lab was to use the magnetometer to find out the location, and also how far below the surface of the Earth a metal pipe is. The measurement of variations in the Earth’s magnetic field is used to tell the location of something below the Earth’s surface. Procedure: Lay out a…
Contraception Combination Pill: Birth control pills that contain a combination of estrogen and progestin (progesterone) (21 days on, 7 placebo) The pill works by preventing ovulation; keeps estrogen high inhibits LSH and no ovulation; high progesterone inhibits LH . Keep endometrium lining thick and prevents sperms from effectively travelling Failure Rate: percentage of women who…
Female Genitalia EXTERNAL Clitoris: sensitive organ; tip of tissue situated externally in front of the vagina. Female clitoris is homologous to the male penis; same embryonic tissue. Both have corpora cavernosa and can become erect. Clitoris has NO direct function in reproduction; female orgasms freq. increase with age. The Mons: Fatty pad of tissue under…
Background Nylon is a polyamide that is formed from the condensation reaction of adipic acid (a dicarboxylic acid) and 1,6 – diaminohexane (a diamine). A scientist working for DuPont, Wallace Carothers discovered Nylon in 1935 and its name is a contraction of New York and London. When Nylon was first discovered it was used to…
Green = lac repressor Red = DNA, operator region Blue = part of the operator (not a hairpin loop, its double stranded DNA) Repressor = a dimer and when it binds to the operator, it creates a loop to make it impossible for polymerase to get through In the lac operon, the beta galactoside bond…
What is an avalanche? , well it’s a large mass of snow and ice or of earth or rock sliding down a mountain side or a cliff. And how does an avalanche occur, well mainly they happen by vibrations caused by movement of the earth such as an earthquake, gunfire, rainy weather, and many more.…
Imagine if this article was written like this: Dyslexia is wehn yuor midn gets wodrs mixde pu. The word dyslexia is derived from the Greek “dys” (meaning poor or inadequate) and “lexis” (word or language). Dyslexia is a learning disability characterized by problems in expressive or receptive, oral or written language. It is characterized by…
Jonas Edward Salk was born to Polish-Jewish immigrants, Daniel B. and Dora Salk, on October 28, 1914. Dr. Salk was born in upper Manhattan, but then moved to the Bronx where he went to school. “His first spoken words were, ‘Dirt, dirt,’ instead of the conventional, uninspired ‘No, no’ or ‘Momma.’ He was a responsive…
Gone are the days when people sent children outside to play to get a little color in their cheeks. They know too much about the dangers of unprotected sun exposure and the threat of skin cancer. Or do they? Despite the fact that 58% of parents remembered hearing about the importance of protecting their children…
Corynebacteria are Gram-positive, aerobic, nonmotile, rod-shaped bacteria related to the Actinomycetes. They do not form spores or branch as do the actinomycetes, but they have the characteristic of forming irregular shaped, club-shaped or V-shaped arrangements in normal growth. They undergo snapping movements just after cell division which brings them into characteristic arrangements resembling Chinese letters.…
In modern society when a person gets sick with the flu or a cold they will usually go about their normal routine with the exception of a sneeze or a cough throughout the day. Sometimes things can be more than what they appear to be. The symptoms start out like the flu with coughing, fever,…
Huntington’s disease, or Huntngton’s chorea, is a genetic disease that causes selective neural cell death, which results in chorea, or irregular, jerking movements of the limbs caused by involuntary muscle contractions, and dementia. It can cause a lack of concentration and depression. It also may cause atrophy of the caudate nucleus, a part of the…
Multiple sclerosis is one of the most misunderstood diseases of this century. Since it’s discovery, there is still no known causes, no proven treatments, and no known cure, yet it affects possibly five hundred thousand people in the United States alone. People need to learn more about this disease so it can be brought to…
Mumps is a disease caused by a virus and occurs only in human beings. Mumps is found all over the world. Mumps is a contagious disease when the salivary glands, on one or both sides of the jaw, swells. Mumps usually occurs in school age children, but young adults may catch the disease. Everyone born…