Life Functions 2

Movement Movement of a cell or an entire

organism allows the organism to find food in its environment and to move away from predators or other threats.

Cilia: hair like structures on the edge of cell membranes that work like millipede legs moving in unison to create a wave like motion that move the individual cell. Some bacteria and protists have these structures.

Movement

Flagella: long tail like projections from the cell membrane that move like a fish tail in order to allow the cell to swim.

Pseudopods: the cell forces the contents of the cell into one part of the cell membrane causing it to extend. Protists such as amoebas use this method of movement.

Movement

Hydrostatic skeleton: the muscles are arranged in circles that contract and push against a liquid interior in order to change the shape of the organism to cause movement.

Exoskeleton: a liquid is secreted from the skin and hardens into a shell that the muscles are attached to. The muscles contract and relax to pull the skeleton in different directions. In order to grow the shell is molted and a new one is secreted and hardens in its place.

Movement

Endoskeleton: an interior solid structure that grows with the body. This can be calcified bone or cartilage. The muscles contract to pull the bones which bend at joints.

Reproduction

The process used to create offspring and pass genetic material from one generation to the next.

Viral life cycles: viruses do not possess the proper cellular structure to reproduce. They will inject the instructions on how to make a virus (either DNA or RNA) into a living cell. From this point there are two different cycles the virus could fallow.

Reproduction

Lytic Cycle: the genetic material injected into the living cell will be expressed by the cell using the instructions to make viruses. Then the viruses will burst out of the host cell killing it and go infect other cells.

Reproduction Lysogenic Cycle: The genetic material becomes integrated

into the cell’s DNA. Every time the cell divides each new cell receives a copy of the viral instructions. Eventually something triggers the viral instructions to become active and the virus enters the lytic cycle.

Reproduction

Asexual: this type of reproduction has an evolutionary advantage in that it can occur very quickly allowing an organism to increase the size of the population and it does not require an organism to find a mate.

Reproduction

Budding: type of asexual reproduction performed by multicellular organisms such as sponges and some plants. The organism grows a new organism out of the parent that is eventually separated and continues to grow into an adult.

Reproduction Binary fission: type of asexual

reproduction performed by prokaryotic cells in which the cell copies the DNA and simply splits in half.

Regeneration: some animals and protists are capable of cutting the organism in half and then allowing the two halves to regenerate or recreate the missing structures.

Mitosis: single celled protists and green algea will perform cell division in order to create a genetically identical offspring.

Reproduction

Conjugation: the major problem with asexual reproduction is that the offspring are all genetically identical to the parent. This would prevent evolution in response to a changing environment. To solve this problem some organisms that reproduce only by asexual reproduction can form tunnels between each other and exchange pieces of genetic material in a process called conjugation. These organisms include both types of bacteria and protists.

Reproduction

Sexual: the advantage of sexual reproduction is the creation of genetically different individuals which provides multiple options for every trait. The disadvantage is this process takes longer and requires the presence of a partner.

Reproduction

External fertilization: in this type of reproduction both the egg and sperm are released into the environment. Fertilization (the fusion of egg and sperm) and development occur outside the body. Normally the parents do not care for their offspring. For this reason thousands of eggs and even more sperm are released to ensure the survival of at least some offspring.

Reproduction Internal fertilization: requires the sperm

to enter the body of the female and fertilize the egg. Being that it is more likely that the sperm and egg will meet, not as many gametes are produced.• Bryophytes: the sperm must swim

through a layer of water to the egg. • Spore production: once the sperm

and egg fuse the plant creates a spore which will grow into the next generation. This is different from a seed because it does not contain a food source for the embryo.

Movement Review Questions• What does moving allow organisms to do?• What are cilia and what type of organisms have these structures?• What is a flagella and how does it function?• What are pseudopods, how do they function, and what types of

organisms use these structures?• How do protists that do not have cilia, flagella, or pseudopods move

around their environment?• What is a hydrostatic skeleton and what types of organisms have them?• What is the difference between an endoskeleton and exoskeleton?• What types of animals have an endoskeleton? Exoskeleton?• What is molting and what does it allow an animal to do?• What is the advantage of having joints in the skeleton?

Reproduction Pollination creating seeds: pollen

carries the sperm from the male part of a plant to the female part of the plant where the egg is located. In gymnosperms the plant makes male and female cones. These plants depend on the wind to carry pollen to the female cones so they must make much more pollen than the flowering plants that attract animals to carry the pollen directly to the next flower. Angiosperms create flowers where the anther produces the pollen and the pistil contains the eggs.

Reproduction

Oviparous: after fertilization occurs the fertilized egg is wrapped in several layers of membrane and laid outside the body to develop. Examples include birds, most reptiles, most amphibians and monotreme mammals (echidna and platypus).

Reproduction Ovoviviparous: after fertilization occurs

the fertilized is wrapped in several layers of membrane and the egg is held inside the body for protection. Examples include sea horses, some snakes, and some frogs.

Reproduction

Viviparous: after fertilization the embryo implants and develops inside the mother. In marsupial mammals the baby is born premature and moves to a pouch where the nipple is located. The rest of development occurs in the pouch with milk providing the nutrition. In placental mammals a specialized organ is created that allows the offspring to fully develop inside of the mother.

Reproduction Review Questions• What are the two ways a virus can reproduce? Explain each cycle.• What are the benefits and disadvantages of asexual reproduction?

Sexual reproduction?• What is budding? Is this asexual or sexual reproduction?• What is binary fission? Is this asexual or sexual reproduction?• What is conjugation? What is the purpose of conjugation and what types

of organisms use this process?• Explain why animals that use external fertilization tend to make more

gamete cells and offspring.• What are oviparous animals? Ovoviviparous animals? Viviparous

animals? Include examples of each.• (Review) What are monotreme mammals? Marsupial mammals?

Placental mammals? Include examples of each.

Response

Organisms have developed specialized structure in order to gather information from the environment and respond to these stimuli. The structures can be divided into two groups: the structure used to process information and structures used to gather information

Response Process information

In single celled organisms the nucleus will process the information received from the environment and formulate a response.

Nerve net: nerve cells are used to transport information throughout the body. The cells are evenly distributed the information is passed from one cell to the next until all of the cells know what is occurring.

Response

Ganglia: a group of nerve cells that collects and process incoming information. This is different from a brain because there are not specialized regions to perform different tasks.

Brain: a group of nerve cells that process incoming information. The brain has specialized structures that divide up tasks such as processing sight and controlling involuntary functions.

Response Specialized structures will collect

information from the environment in order to help the organism understand what is occurring around it. Eye spots: are used by some

protists and simple animals such as flatworms to detect the presence of light.

Eyes: used by many animals. There are different types. Complex eyes of insects have many lenses allowing them to see movement better than eyes with a single lens while other eyes can see color very well.

Response Ears: Used by animals to hear their

surroundings. Some animals have just a tympanic membrane and are unable to hear distinct sounds while others have external ear structures allowing them to collect sound more efficiently

Taste: can be used to distinguish between organisms.

Smell: can be used to locate predators or prey.

Lateral line: found in fish and amphibians, used to detect disturbances in the water.

Response Review Questions

• How do single celled organisms process information from the environemnt?

• Explain how a nerve net works. Provide examples of animals that use this system.

• Explain the difference between ganglia and brain.

• What is a lateral line, what does it do, and what types of organisms have this structure?

Behaviors

Behaviors can be divided into two groups. Learned behaviors which are the result of an animal’s

experiences. Allows for adaptation of behaviors increase the chances of survival. It is generally believed that only animals with complex nervous systems can learn. The amount of learning an animal is capable of is determined by life span and amount of parental care. Animals with shorter life spans and little to no parental care have fewer learned behaviors.

Innate behaviors are encoded in the DNA of the organism and inherited like physical traits. This means all organisms will perform these types of behaviors the same from birth no matter the conditions they are raised in.

Examples of Innate Behaviors

Suckling: a reflex that exists in mammals that allows them to feed from their mothers instinctively

Taxes: some organisms such as insects exhibit this type of behavior which results in movement either toward or away from the stimulus.

Migration: the movement of organisms to a new location in response to the time of year (mating time or to find food in the different seasons)

Examples of Innate Behaviors

Circadian rhythm: the 24 hour living pattern of an animal

Estivation: lowering of body temperature to go into a state of dormancy to escape extremely hot conditions.

Hibernation: lowering of body temperature to go into a state of dormancy to escape extremely cold conditions.

Examples of Learned Behaviors*****ADD TO YOUR NOTES*****

Imprinting: Rapid form of learning that occurs at a young age and is essential for survival. Examples include prey animals such as zebras learning to walk in hours and ducks fallowing their mom.

Examples of Learned Behaviors

Habituation: Animals learn not to respond to a repeated action.

Reasoning: the ability to solve unfamiliar problems in new situations.

Trial and error learning: process of elimination where an animal tries all solutions to a problem in order to discover the correct one.

Examples of Learned Behaviors

Classical conditioning: An animal learns to associate a stimulus with a response that would not normally occur. Ex. Pavlov did an experiment using a dog and a bell. He would ring the bell and give the dog a treat. Eventually the dog would salivate at the sound of the bell even if he was not given a treat.

Social Behaviors Social behaviors can be learned, innate

or a combination of the two. These behaviors are used to communicate between organisms. Territoriality: the physical space an

animal defends against others of the same species and gender. The animal may be defending breeding area, feeding are, or mates. This reduces conflicts, controls growth, and ensures efficient use of the environment. Pheromones which are chemicals secreted and recognized by the same species are used to mark territory.

Social Behaviors

Aggression: used to intimidate another animal so that fighting is not required. Fighting carries the risk of injury even to the winner which decreases the chances of surviving. Animals fight or threaten one another to defend young, territory, or resources like food. Aggressive behavior includes postures, bird calling, teeth bearing, or growling.

Social Behaviors

Courting: Behavior that males and females carry out to attract mates. Animals use elaborate color patterns, songs, dances, and decorated homes to attract mates.

Dominance hierarchy: A form of social ranking among family groups. The term “pecking order” comes from the behavior of chickens. The top ranking chicken pecks all others and the lowest gets pecked by all other chickens.

Behavior Review Questions

• What is the difference between innate and learned behaviors?

• What types of behaviors can evolve and why?• How can you tell if a behavior is innate?• List and explain six innate behaviors.• List and explain four learned behaviors.• Are social behaviors learned or innate?• List and explain four social behaviors.