* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 22 and 27 and 28
Survey
Document related concepts
Embryonic stem cell wikipedia , lookup
Cell culture wikipedia , lookup
Dictyostelium discoideum wikipedia , lookup
Hematopoietic stem cell wikipedia , lookup
Chimera (genetics) wikipedia , lookup
Cellular differentiation wikipedia , lookup
Neuronal lineage marker wikipedia , lookup
Cell theory wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
List of types of proteins wikipedia , lookup
State switching wikipedia , lookup
Microbial cooperation wikipedia , lookup
Transcript
22.5 Plant Hormones and Responses KEY CONCEPT Plant hormones guide plant growth and development. 22.5 Plant Hormones and Responses Plant hormones regulate plant functions. • Hormones are chemical messengers. – produced in one part of an organism – stimulates or suppresses activity in another part 22.5 Plant Hormones and Responses • Gibberellins are plant hormones that produce dramatic increases in size. – ending seed dormancy – rapid growth of young seedlings – rapid growth of some flower stalks 22.5 Plant Hormones and Responses • Ethylene causes the ripening of fruits. – some fruits picked before they are ripe – sprayed with ethylene to ripen when reach destination 22.5 Plant Hormones and Responses • Cytokinins stimulate cytokinesis. – final stage in cell division – produced in growing roots, seeds, and fruits – involved in growth of side branches 22.5 Plant Hormones and Responses • Auxins lengthen plant cells in the growing tip. – stimulates growth of primary stem – controls some forms of tropism • A tropism is the movement of plant in response to an environmental stimulus. 22.5 Plant Hormones and Responses Plants can respond to light, touch, gravity, and seasonal changes. • Phototropism is the tendency of a plant to grow toward light. – auxins build up on shaded side of stem – cells on shaded side lengthen – causes stem to bend toward light 22.5 Plant Hormones and Responses • Thigmotropism is a plant’s response to touchlike stimuli. – climbing plants and vines – plants that grow in direction of constant wind 22.5 Plant Hormones and Responses • Gravitropism is a plant’s response to Earth’s gravitational pull. – positive gravitropism is downward growth (roots) – negative gravitropism is upward growth (shoots) 22.5 Plant Hormones and Responses • Some plants have rapid responses not involving growth. – Some responses protect plants from predators. – Some responses allow plants to capture food. 22.5 Plant Hormones and Responses • Photoperiodism is a response to the changing lengths of day and night. – triggers some plants to flower – triggers fall colors/winter dormancy of deciduous trees 27.1 Adaptive Value of Behavior KEY CONCEPT Behavior lets organisms respond rapidly and adaptively to their environment. 27.1 Adaptive Value of Behavior Behavioral responses to stimuli may be adaptive. • Detecting and responding to stimuli is key to an individual’s survival. • Internal stimuli tell an animal what is occurring in its own body. – hunger – thirst – pain 27.1 Adaptive Value of Behavior • External stimuli give an animal information about its surroundings. – sound – sight – changes in day length or temperature 27.1 Adaptive Value of Behavior • Specialized cells that are sensitive to stimuli detect sensory information. – information is transferred to the nervous system – nervous system may activate other systems in response • Animal behaviors help to maintain homeostasis. 27.1 Adaptive Value of Behavior • Kinesis and taxis are two types of movement-related behaviors. – Kinesis is an increase in random movement. – Taxis is movement in a particular direction. 27.1 Adaptive Value of Behavior Internal and external stimuli usually interact to trigger specific behaviors. • Most behaviors are a response to both internal and external stimuli. • External stimuli may trigger internal stimuli 27.1 Adaptive Value of Behavior Some behaviors occur in cycles. • A circadian rhythm is the daily cycle of activity. – occurs over 24-hour period – run by a biological clock 27.1 Adaptive Value of Behavior • Behaviors may occur daily, monthly, seasonally, or annually. – During hibernation, an animal enters a seasonal dormant state. 27.1 Adaptive Value of Behavior • Behaviors may occur daily, monthly, seasonally, or annually. – During hibernation, an animal enters a seasonal dormant state. – During migration, animals move seasonally from one portion of their range to another. 27.2 Instinct and Learning KEY CONCEPT Both genes and environment affect an animal’s behavior. 27.2 Instinct and Learning Innate behaviors are triggered by specific internal and external stimuli. • An instinct is a complex inborn behavior. • Instinctive behaviors share several characteristics. – innate, or performed correctly the first time – relatively inflexible 27.2 Instinct and Learning Many behaviors have both innate and learned components. • Learning takes many forms. • Habituation occurs when an animal learns to ignore a repeated stimulus. 27.2 Instinct and Learning • In imitation, animals learn by observing the behaviors of others. – young male songbirds learn songs by listening to adult males – snow monkeys and potato-washing behavior 27.2 Instinct and Learning Learning is adaptive. • Animals that can learn can better adapt to new situations. • In associative learning, a specific action is associated with its consequences. • Conditioning is one type of associative learning. 28.1 Levels of Organization KEY CONCEPT The human body has five levels of organization. 28.1 Levels of Organization Specialized cells develop from a single zygote. • Organisms are made up of specialized cells. red blood cell nerve cell 28.1 Levels of Organization Specialized cells develop from a single zygote. 28.1 Levels of Organization • Zygotes first divide into embryonic stem cells. • Stem cells develop in two stages. – determination, or committing to become one cell type – differentiation, or acquiring specialized structures and functions 28.1 Levels of Organization Specialized cells function together in tissues, organs, organ systems, and the whole organism. • Specialized cells perform specific tasks. • Tissues are groups of similar cells working together. – epithelial tissue – connective tissue – muscle tissue – nervous tissue cell tissue 28.1 Levels of Organization • Organs are different tissues working together. • Organ systems are two or more organs working together. • Organism is all organ systems working together. ORGANS ORGAN SYSTEM ORGANISM 28.1 Levels of Organization • There are 11 major organ systems in the human body. 28.1 Levels of Organization How are body systems connected? What are your body systems? Make a chart System Function • Name 3 body systems • What is the function of each system • Then list 2 organs in each body system How do the systems interact? Short Answer: Describe how 2 of the systems you listed are connected. Organs 5.5 Multicellular Life KEY CONCEPT Cells work together to carry out complex functions. 5.5 Multicellular Life Multicellular organisms depend on interactions among different cell types. CELL TISSUE leaf stem vascular tissue ORGAN lateral roots primary root root system • Tissues are groups of cells that perform a similar function. • Organs are groups of tissues that perform a specific or related function. • Organ systems are groups of organs that carry out similar functions. shoot system SYSTEMS 5.5 Multicellular Life Specialized cells perform specific functions. • Cells develop into their mature forms through the process of cell differentiation. • Cells differ because different combinations of genes are expressed. • A cell’s location in an embryo helps determine how it will differentiate. Outer: skin cells Middle: bone cells Inner: intestines 5.5 Multicellular Life Stem cells are unique body cells. • Stem cells have the ability to – divide and renew themselves – remain undifferentiated in form – develop into a variety of specialized cell types 28.2 Mechanisms of Homeostasis KEY CONCEPT Homeostasis is the regulation and maintenance of the internal environment. 28.2 Mechanisms of Homeostasis Conditions within the body must remain within a narrow range. • Homeostasis involves keeping the internal environment within set ranges. 28.2 Mechanisms of Homeostasis • Control systems help maintain homeostasis. pore Sensors gather data sweat glands Control center gathers data and sends response Targets respond to change Communication system delivers messages to target organs and tissues hair follicle muscle goose bump 28.2 Mechanisms of Homeostasis Negative feedback loops are necessary for homeostasis. • Feedback compares current conditions to set ranges. • Negative feedback counteracts change. Negative Feedback Loop Holding breath, CO2 levels rise, O2 / CO2 level returns to normal Control system forces exhale, inhale 28.2 Mechanisms of Homeostasis • Positive feedback increases change. – Torn vessel stimulates release of clotting factors platelets blood vessel fibrin clot white blood cell red blood cell – growth hormones stimulate cell division 28.3 Interactions Among Systems KEY CONCEPT Systems interact to maintain homeostasis. 28.3 Interactions Among Systems Each organ system affects other organ systems. • An organ system must do a specific job. • Organ systems must also work together to keep the organism healthy. 28.3 Interactions Among Systems • Organ systems must also work together to keep the organism healthy. – Organ systems work together to produce Vitamin D. – Thermoregulation maintains a steady body temperature. UV light 1 Skin absorbs UV light 2 Liver produces inactive vitamin D 3 Kidneys produce active vitamin D 4 Active vitamin D used in bones 28.3 Interactions Among Systems A disruption of homeostasis can be harmful. • Homeostasis can be disrupted for several reasons. – sensors fail – targets do not receive messages – injury – illness 28.3 Interactions Among Systems • Short-term disruption usually causes little or no harm. • Long-term disruptions can cause more damage. • Diabetes is a serious long-term disruption of homeostasis. pancreas 1 Pancreas cells attacked;insulin declines 2 Blood glucose levels rise, fats kidneys 3 Body burns fat; blood more acidic, 4 Cells impaired; all organs damaged.