FINAL-REVIEWER-IN-GENERAL-BIOLOGY-2.docx

**FINAL REVIEWER IN GENERAL BIOLOGY 2** **FEEDBACK MECHANISM** - **Thermoregulation**- a process that allows your body to [maintain] its core internal temperature - **Homeostasis**- refers to any process that living things use to actively maintain [fairly stable conditions] necessary...

**FINAL REVIEWER IN GENERAL BIOLOGY 2** **FEEDBACK MECHANISM** - **Thermoregulation**- a process that allows your body to [maintain] its core internal temperature - **Homeostasis**- refers to any process that living things use to actively maintain [fairly stable conditions] necessary for survival - **Stimulus**- a stimulus is anything that [makes an organism or a part of an organism react] in some way - **Response**- a [reaction], as that of an organism or a mechanism, to a specific stimulus - **Receptors**- an [organ or cell able to respond] to light, heat, or other external stimuli and transmit a signal to a sensory nerve. - **Negative Feedback** - It is the most common mechanism for homeostasis. Negative feedback [negates change and stabilizes systems]. Ex. Sweating to PREVENT body heating - **Positive Feedback** - In positive feedback mechanisms, the response to a stimulus does not stop or reverse it but instead [keeps the sequence of events going up]. Ex. Increased heart pump during exercise to SUPPLY the body with more oxygen. **Parts of a Nerve Cell (Neuron)** **Dendrite**- [Receives] information and passes it to the cell body **Cell Body**- Location of [nucleus] and organelles **Axon**- Single portion that [carries information away] from the cell body **Sensory Neuron**- [receives] information. **Interneuron**- [processes] information. Brain and spinal cord **Motor Neuron**- [cause] [action] in muscles or glands. Make things "move". Neuron - a Nerve Cell Number of types Neurons - Three **Types of Neurons** ❖ **Mechanoreceptors** - Responds to [movement] and pressure LOCATION: skin SENSES INVOLVED: touch, hearing ❖ **Thermoreceptors** - Responds to [heat] loss or gain LOCATION: skin SENSES INVOLVED: touch ❖ **Pain receptors** - respond to tissue [damage] LOCATION: skin SENSES INVOLVED: touch ❖ **Chemoreceptors** - Respond to [chemicals] LOCATION: nose, mouth SENSES INVOLVED: taste, smell ❖ **Photoreceptors** - Respond to [light] LOCATION: eyes SENSES INVOLVED: sight **GENETICS** - **Alleles**- one of the different [forms of genes] - **Genetics**- the scientific [study of biological inheritance] - **Genomes**- an organism\'s complete [set of genetic instructions] - **Heredity**- the [passing on of traits] from parents to their offspring - **Inheritance**- process by which genetic information is passed on [from parent to child] - **Genes**- a [unit of heredity] that is transferred from a parent to offspring and is held to determine some characteristic of the offspring - **Dominant**- a trait that [dominates or covers up] the other form of the trait - **Recessive**- a trait that is [covered up] by a dominant trait - **Phenotype**- the [physical appearance] of an organism - **Genotype**- the [genes] of an organism - **Homozygous**- an organism with two alleles that are the same - **Heterozygous**- an organism with two different alleles for a trait **Chromosomes** The sex of an individual is determined by the sex chromosomes called the X chromosome and the Y chromosome. Females have two X chromosomes (XX). Males have an X chromosome and a Y chromosome (XY). Female gametes (eggs) therefore always carry an X chromosome.