lecture 18 Flashcards
1
Q
body temperature
A
- thermoregulation is the maintenance of body temp within a tolerable range
- most of life’s processes are very sensitive to body temp
- every animal species has a optimal temp range
- important to keep temp within this range
- humans: 37 degrees
- endotherms are warmed and heated by their own metabolism
- ex) humans and birds
- ectotherms gain most of their heat from the environment and other external sources
ex) amphibians and fish
2
Q
heat can be exchanged with the environment in four ways
A
- conduction
- convection
- radiation
- evaporation
3
Q
conduction
A
- transfer of heat in between molecules by direct contact
- heat always moves from the hotter object to the colder object
4
Q
convection
A
-transfer of heat by the movement of fluid across a surface
5
Q
radiation
A
- emission of electromagnetic waves
- can transfer heat in between objects that are not in direct contact
6
Q
evaporation
A
- loss of heat from the surface of a liquid
- happens when a molecule obtains enough energy to leave the liquid and become gas
7
Q
adaptation for thermoregulation
A
- metabolism
- insulation
- circulation
- evaporative cooling
- behavioural repsonses
8
Q
metabolism
A
- hormonal changes in cold weather boost the metabolic rate of mammals, increasing heat production
- additionally moving around more increases heat production
- shivering: contraction of skeletal muscles
9
Q
insulation
A
- hair, feathers, or fat
- raising or fur or feathers in response to cold traps heat against the surface of the body (goose bumps: humans)
10
Q
circulation
A
- heat loss can be controlled by the changing the amount of blood flowing to the skin surface
- blood vessels near the surface of the skin dilate and constrict
- conserves heat in the bodies trunk when necessary
11
Q
evaporative cooling
A
- painting, sweating, and spreading saliva on bodily surfaces all act to decrease body temp
- humans sweat
12
Q
behavioral responses
A
- migration of birds to different climates
- basking in the sun when cold or seeking shade when hot
- bathing functions to cool immediately
13
Q
excretion
A
- animals must dispose of nitrogenous wastes
- excretion is the disposal of metabolic wastes
- nitrogenous wastes are products of protein metabolism
- ammonia is poisonous
- water soluble and easily disposed of in animals
- it is converted to urea which is less toxic and much safer to store within the body
- urea and uric acid require energy to produce
14
Q
reproduction:asexual
A
- can be sexual or asexual
- asexual reproduction results in offspring genetically identical to the parent
- allows for the production of many offspring very quickly
- binary fission: two equally sized cells are produced from one parent cell
- budding: two cells of unequal size are produced from one parent cell
- parthenogenesis: development of an unfertilized egg
- regeneration: entire body parts of some animals can be regenerated
- in humans regeneration is limited to healing and tissue repair
- liver has extensive regenerative capacity
15
Q
reproduction: sexual
A
- sexual reproduction: fusion of haploid gametes from two parents forms a diploid zygote
- results in extensive genetic variation within offspring
- some animals exhibit hermaproditism
- both male and female reproductive organs are present on the same animals
- in humans this can sometimes occur by mistake
16
Q
reproduction: external fertilization
A
- occurs in many fish and amphibians
- eggs and sperm are released into water for fertilization to take place
- often physical contact is not required
- timing is very important because the eggs must be ripe
17
Q
reproduction: internal fertilization
A
- sperm are deposited within or close to the female reproductive tract and gametes unite within the tract
- an adaptation the omits the need for water
- requires copulation: sexual intercourse
18
Q
nervous system: radial symmetry
A
- the organization of the animals nervous system correlates with form of body symmetry
- animals that are radially symmetrical:
- have web-like nervous systems
- ex) nerve net in hydra
- diffuse throughout the animal body
- no central or peripheral nervous system
19
Q
nervous system: bilateral symmetry
A
- bilateral symmetry:
- these organisms tend to move through their environment
- requires a head with concentrated sensory organs
- two major adaptions are found within this group:
- cephalization:concentration of the nervous system st the head end
- centralization: a central nervous system(CNS) distinct from the peripheral nervous system
20
Q
nervous system: vertebrate nervous system
A
- highly specialized
- CNS: brain and spinal cord
- PNS: peripheral nerves
- vertebrate and skull function to protect nerves
21
Q
senses
A
- senses are important for animal function
- guide movement
- salmon use senses to find their breeding areas
- bears use their senses to locate salmon
- collectively these senses gather info that facilitates feeding, migrating, and other behaviors
- sensory info arrives as a sensation to the brain
- how the brain interprets this info is referred to as perception
- sensory receptors:
- detect stimuli and convert the info into an action potential that is then sent to the brain
- these receptors are highly specialized to pick up stimuli and are located within sensory organs:
- eyes, nose taste buds
- the stimulus energy is transmitted into an action potential which is what will then be sent to the brain
22
Q
five categories of sensory receptors
A
- many types of receptors can be found on the skin alone
1. pain receptors
2. thermoreceptors
3. mechanoreceptors
4. chemoreceptors
5. electromagnetic receptors
23
Q
pain receptors
A
-detect stimuli that are considered dangerous
24
Q
thermoreceptors
A
-detect heat or cold, monitors body temp
25
Q
mechanoreceptors
A
-respond to any changes in mechanical energy such as touch, pressure, and sound
26
Q
chemoreceptors
A
- repsond to chemicals
- the nose and the mouth detect chemicals in the enviornment and those about to enter the body
- internal receptors detect chemicals within the body
27
Q
electromagentic receptors
A
-respond to electricity, magnetism, and light (detected by photoreceptors)
28
Q
vision
A
- a number of different eyes types have developed in vertebrates
1. simple eye: - these are cups that sense light intensity and direction
- does not detect an image
2. many-lens compound eyes of insects: - each unit of the animal has a lens and picks up light from a small portion of the field view
- generates an image from that area only
- all of the lenses together generate the entire picture which is pixelated
3. single-lens eyes of squid: - similar to a camera
- single lens focuses the image using special muscles in the eye
29
Q
vertebrate eye
A
- single lens
- cornea and the flexible lens focus the light (via bending) on the retina which contains photoreceptor cells
- light passes through the lens which bends the light ray such that is falls on the retina
- near sighted individuals are only able to see things that are close
- the object is focused within the eye and not on the retina
- far-sighted individuals are only able to see things that are far away
- the object is focused behind the retina
30
Q
locomotion
A
- locomotion is the active travel from one place to another
- the animal must be able to overcome both gravity and friction
- animals that swim are supported by the body of water but are also slowed by drag created in the water
- animals that move on land are less opposed by friction (air is lighter than water) but they must support their body weight against the force of gravity:
1. hopping
2. running
3. walking
4. crawling
31
Q
skeletal support
A
- skeletons provide important structure for movement, protection and support
- muscles pull against the skeleton during movement
- protects internal organs within the cavity
- hydrostatic skeletons:
- fluid held under pressure in a body cavity
- worms and cniadrians
- exoskeleton:
- hard, external cases
- chitinous, jointed exoskeletons of arthropods
- includes shells of some molluscs
- endoskeletons:
- hard or leathery supporting elements within the soft tissue of an animal
- vertebrate endoskeleton is composed entirely of cartilage and bone
- sharks have an endoskeleton composed entirely of cartilage
