Bio 3032 Animal Responses To Their External Environment Flashcards
Fight or flight response
Also known as immediate stress response
-activated by hormones responding to animal’s sight, hearing and smell of predator attacking
What is the importance of receptors
-animals use receptors to detects sensory stimuli in their environments
-detection of sensory stimuli
-appropriate responses to these stimuli
-essential for animal survival
What are the 5 senses
Touch
Smell
Sight
Hearing
Taste
Photoreceptor (light)
-animals need to sense light in order to see surroundings.
-unicellular organisms > simple light spot or light sensitive pigmented area
-primitive eyes > only detect light & dark
-compound eyes > exist of many seperate parts known as ommatidia, have a mosaic vision of different dots and light intensities which are very good at detecting movement
-very complex eyes > lenses to focus light, retina which recieves the light. Retina made up of rods and cones.
-rods detect darkness and light
-cones detect colour
Structures in the ear that detect sound and are used for balance
Auditory (sound) receptors
-sound is carried by waves traveling through the air or water
-mammals (humans) sound waves are detected by outer ear and cause the ear drum to vibrate
-sound vibrations are then passed through 3 small bones, malleus, incus and stapes, in the middle ear
-from middle ear to inner ear, cochlea, where auditory nerves carry the sound messages to the brain
-ear is used for balance and sensing position with respect to surroundings
-inner ear have three semicircular canals that sense changes in the body’s movement.
-as body moves, fluid within the canals causes hair cells in the canals to move
-hairs project into a gel-like material containing calcium carbonate crystals (otoliths or ear stones)
-stimulate nerves to send messages to brain about positional changes
Thermoreceptors (heat)
-animals detect heat with nerve endings in the skin
-heat receptors or Thermoreceptors to detect heat in example snakes
-receptors sense infrared light (form of heat)
Chemoreceptors (chemical)
-respond to chemicals in the environment
-taste food
-detect prey
-find mates
-defending
-mark and recognize territory
-communication between social animals that live in colonies (ants etc)
-taste > detection of chemicals in liquid or solid form (sweet, sour, salty, bitter)
-smell > detection of chemicals in air or water.
Mechanoreceptors (touch, pressure, gravity, stretch, movement)
-stimulated by touch, pressure and movement
-nerve endings in animal’s skin can detect heat, cold, touch, pain and pressure.
-butterflies have hair on wings to detect air pressure changes
-cats have sensitive whiskers
-fish use lateral line system
-statocysts are used for equilibrium.
Explain how fish use mechanoreceptors
fish use lateral line system. Water flowing on both sides bends sensory hairs in special mechanoreceptor cells along lateral line. Cells change movements into electrical impulses that travel along nerves to the brain. Helps to orientate the fish in the water and monitor changes in its environment. Use it to detect posistion in water, to monitor water currents and vibrations and waves produced by moving objects.
Explain statocysts
-many invertebrates have sensitive organs called statocysts that are used for equilibrium
-it consists of a cup-like organ containing granules of calcium carbonate known as statoliths
-statoliths stimulate hairs or cilia on receptor cells that send messages on animal’s position to the brain via nerves.
-helps to orientate animal with regard to its surroundings
electromagnetic receptors
-detect electricity and magnetism
-fish surround themselves with electric field
-any disturbance in the field can be detected and avoided if percieved as a danger
-electric eel can stun prey with an electric shock
-magnetic fields surrounding earth from pole to pole
-birds species use these field to identify direction and navigate long distances
Social hierarchy
Has a Dominant animal to which the rest are submissive
Territory
An area that an animal marks and defends against other animals of the same species
Explain territoriality
-where an animal finds and uses the resources it needs to survive in its niche
-teritory that is defended is sometimes part of the home range
-animals hold territory by aggressive behavior
-urine, special scent glands, vocal calls
-advantage of holding a terriotry is that holder has access to resources of the territory (food, water, shelter, females, place to rear young.
-strongest animals are able to hold territories so they are most likely to breed and pass on genes to next generation.
Explain hierarchies
-many groups have a social hierarchy with dominant animal and the rest being submissive
-dominant may be male or female
-african gorilla has male silverback dominant
-pack of wolves have alpha male and female, with subordinate adults and cubs
-elephants are matriarchal have hierarchy with older female at head.
-dominant animal remain in position as long as they are fit and healthy
-once order is established, less tension and infighting
-benefits group and helps them survive
What is social organization
-Social organization and cooperation are strategies that enhance the survival chances of certain species
What is pair bonding
Pair bonding leads to a stable relationship between male and female, and allows them to cooperate in mating and rearing of their young
Parental care
Species that carry out parental care produce only a few offspring at a time but it expend varying amounts of time and much energy in their care. This ensures that these offspring will have a relatively high chance of survival.
Explain social organisation
-ants, bees, wasps live in colonies with a queen in control
-insects have evolved to carry out specific tasks
-queen lays eggs whereas drone bees, look after hive and pupae
-division of labour and highly ordered way of life benefits insects in providing food & caring for young of hive or colony
-major advantage is protection
-larger and usually male animals are positioned to protect females and young members
-cooperative hunting is more chance of successful kill and more regular supply of food
-you g learn from experienced older members which ensures successful survival
-disadvantage is competition
-members of group compete for resources
-same species mean same resource requirements so competition will be intense
-infection or disease strikes and could quickly spread and could lead to entire group dying out
R strategy of reproduction
-noticeably fish, amphibians and some insects
-lay very large numbers of eggs at a time
-once eggs are hatched, young is left to fend for themselves
-results in a high mortality rate however enough young survive to carry on species
-parents put energy into producing eggs instead of caring for young
