The extinction vortex is what happens as a population decreases and becomes more vulnerable to extinction from a variety of causes. begins when one species in an ecosystem goes extinct and other species follow. is what happens when competing species fight over a single niche, often driving both species to extinction. is a spiral of events that occur once a species has become overcrowded through excess reproduction. is a spiral of events that includes introduction of competing species, overexploitation, and disease, in that order.

Fill in the blank 1. digestion occurs in the small intestine through the action of enzymes. 2. urea, excess water, and other waste materials are eliminated in a water fluid called 3. can cause infections by injecting dna or rna into hosts. 4. the human immune system produces in response to a vaccine, which later can bind to and destroy a pathogen if it invades. 5. are structures that link bone to bone at a joint 6. in the heart, blood flows from the right atrium to the right ventricle, where it is pumped to the the words i can use are: lymphocytes gliding pivot gas urine absorption dermis fulcrum lungs chemical viruses capillary vertebrae esophagus tendons antibodies synapses ligaments kidneys pathogens

Mulitple choice which of the following is a function of the nucleus? a. stores dna b. stores sugars c. builds proteins d. packages proteins

If one were to horizontally divide the earth in half at the equator each half would be a