biology final Flashcards
Muscle contraction
Actin and myosin filaments slide past each other
- The release of calcium ions causes a molecule complex (troponin/ tropomyosin) to be removed from binding sites on actin filaments
- ATP powers the ability of myosin heads to bind actin and cause the filaments to slide past each other
Muscle fiber types (Slow twitch)
endurance excercise
- Aerobic
-Good capillary supply to provide O2 and biomolecules
- Myoglobin is a respiratory pigment that causes dark color
Muscle fiber types (Fast twitch)
Power excercise
- Anaerobic
- Relies on stored glycogen
Sensory receptor types
Mechanical receptors: pressure, vibrations,etc..
Chemoreceptors: chemicals
Electromagnetic receptors: Light,etc…
Types of mechanoreceptor based senses:
-pain
- touch
- pressure
- temperature (thermoreceptors)
- hearing: picking up vibrations in the air
- Balance
- gravity/ acceleration
- Proprioception: senses of limb position
Statocyst
A structure in some invertebrates that is a fluid-filled sac lined with cilia that detect the pressure of a small crystal (statolith)
Hearing
Detects vibrations
- pinna or other structures may help gather airbourne sounds
Tympanum (eardrum)
+1 or more inner ear bones transmit sounds to the cochlea
- cochlea is lined with cilia-based mechanoreceptors
- balance/ acceleration
- detected by vestibular apparatus and semicircular canals
- contain tiny crystals detected by mechanoreceptors
Chemoreceptor
smell- detection of airbourne (volatized) chemicals
Taste: Detection of dissolved chemicals (in saliva)
Vomeronasal organ: used to detect pheromones (such as from rivals, potential mates or pray)
Balance/Acceleration
detected by vestibular apparatus and semicircular canals (allows you to view in 3d)
- they contain tiny crystals picked up by mechanoreceptors
Mating Behaviors
explained through sexual selection (type of natural selection that creates differences between males and females)
Sexual dimorphism
males and females of many species are different in morphology
- includes things like color (males usually most colorful), body size (females usually larger, mating behaviors)
Differences in mating behaviors (male-male competition)
males spend much of time fighting and defending resources while trying to attract females
Differences in mating behaviors (female choice)
females usually determine which male they will mate with
females choose males based on
- Potential resources
- Indicator traits (handicap traits) that signal the males potential quality
- these are typically bad for a males long term survival
Life history
study of tradeoffs in how animals make decisions about how many offspring to have or whether to provide parental care
Monogamy
having just 1 mate
- beneficial including more parental care by males
- cost is potentially fewer offspring
Polygamy
Having many different mates (usually one male monopolizes many females)
- Beneficial in terms of maximizing the number and diversity of male offspring
- cost is lack of parental care by means
Fewer v offspring
- some animals have many offspring with little parental care - other animals with more parental care have fewer offspring but offspring survive longer
Iteroparity v. Semeloparity
Can reproduce many times during lifespan (perennials)
- Allows animals to reproduce across different breeding seasons
- can have lots of offspring since energy not held back for bodily maintenance
- Reproduce once and then die (animals)
Altruism
behaviors that help others at own expense
Symbioses
close, often long-term interactions between species benefits, the other is unaffected
Paratism
one species benefits, the other is unaffected
Mutualism
Both species benefit
Biodiversity
Number of species in a community
- the higher the biodiversity, the more stable the community
Types of species that influence biodiversity: (foundation species)
increase biodiversity by adding new niches
Types of species that influence biodiversity: (dominant species)
decreases biodiversity by over-using resources
Types of species that influence biodiversity: (Keystone species)
increases biodiversity, predator that keeps herbivores from overeating the producers
Succession
change in species composition overtime in a community
- these changes are triggered by disturbance
Primary
After very strong disturbance starts with few species and resources for them
Secondary
result of a milder disturbance
Trophic levels
energy enters ecosystems in the form of sunlight
- Some of that energy is transformed into carbohydrate energy by producers through photosynthesis
Bioaccumulation and biomagnification
- certain types of toxic chemicals are stored in animal fatty tissue (bioaccumulation)
- as consumers eat these organisms, they become more concentrated at higher trophic levels (biomagnification)
Nervous system
use a network of specialized cells (neurons) to transmit rapid electrochemical messages
Nervous system facts
- many neurons are directly connected to eachother
- axon produces neurotransmitters that cross the synapse and are detected by receptors on a neighboring dendrite
- Within a neuron, the electrical signal (action potential) moves along the axon due to differences in sodium and potassium ion concentration
Muscles
Actin and myosin filaments slide past eachother
- the release of calcium ions causes a molecule complex (troponin/tropomyosin) to be removed from binding sites on actin filaments
- ATP powers the ability of myosin heads to bind actin and cause the filaments to slide past each other
Types of eyes
Compound: present in many invertebrates
- Has many seperately focusing lenses covering its surface
Complex focusing: Has a single internal lens
Choroid
In many vertebrates, it is dark and non-reflective to absorb excess light
- Active during the day/bright environment
- In others, it is reflective to stimulate photoreceptors
- active during the night/dark environments
Photoreceptor types
-rods: light/dark
-cones: color vision
Dichromatic: 2 cone types (blues and yellows)
Trichromatic: 3 cone types (adds reds and greens)
Tetrachromatic: 4 cone types
Infared vision
animals such as certain snakes have heat-sensitive photoreceptors to track endothermic prey
Bioelectric field detection
use by aquatic animals to detect prey items
magnetic field detection
Perceive magnetic field of earth for long-distance migration
Types of behaviors
migratory- animals moving from place to place
- Looking for more resources and food
- looking for better climate
- looking for more mates
foraging
behaviors focused on finding /capturing food sources.
Cooperative social behaviors
-Often due to altruism (one individual helps another at cost to itself)
-These altruistic behaviors are usually directed as close relatives of one’s own species
fitness
equals survival + reproduction
Inclusive fitness
obtained from close relatives surviving and reproducing
Kin selection
type of natural selection that focuses on helping others
Eusocial
-Live in colony
-Individuals have functional roles that they are raised into (reproductives such as queens and kings),(workers),(soldiers)
-Individuals have very high relatedness
-Individuals are involved in cooperative care of young
Eusocial colonies
animals functioning according to kin selection, where workers and soldiers get more fitness from helping parents reproduce than they would get if they tried to reproduce on their own
Ecology
the study of interactions between organisms and their environment
Population
group of individuals of the same species in the same area (such as animal diversity)
Community
groups of individuals of different species in the same area (such as biodiversity)
Ecosystems
Communities in the same area and nonliving parts of the environment
Autotroph
organism that builds it’s own energy molecules (usually carbs) using external energy source (usually sunlight) ( autotrophs are PRODUCERS)
- Plants, algae
Heterotroph
consume other organism to obtain their biomolecules (Heterotrophs are CONSUMERS)
Types of community interactions (competition):
individuals competing with eachother for resources
Types of community interactions (Niche):
each species has its own niche which is the set of food items, habitats, etc. it needs
Types of community interactions (Potential niche):
all possible resources for a species (fundamental niche)
Types of community interactions Actual (realized) niche:
what a species actually can use due to competition and predation
Predation
one species is a resource for another species
Carnivore
one animal eats another animal
Herbivore
animal eats plant
Parasite
one organism is a host for the parasite
Aerobic respiration
biological process by which food gluclose is converted into energy in the presence of oxygen
anaerobic respiration
cells can breakdown sugars to generate energy in the absence of oxygen
biomass
the mass of living biological organisms in a given area or ecosystems at a given time
carbon fixation
the addition of CO2 to organic molecules (usually carbohydrates) to prevent it from remaining in the atmosphere in that free state
greenhouse effect
A warming of earths surface and troposphere caused by the presence of water vapor CO2 has methane, and other gases in the air. Water vapor has the largest effect
Nitrogen fixation
an important microbe-mediated process that converts dinitrogen to ammonia using the nitrogen protein
eutrophication
emission of nutrients, mainly via water but also through air, which find their way through ecosystems and affect their relative growth patterns, posing a threat to biodiversity.
Dead zone
when O2 in the water is so low it can no longer sustain marine life in bottom or near bottom waters- literally a dead zone
Invasive species
an introduced species to an environment that becomes overpopulated and harms its new environment
Symbiosis
any type of a close and long term biological interaction between two biological organisms of different species
Commenalism
A symbiotic relationship in which one species benefits while the other species is not affected
Paratism
A symbiotic relationship where one species (the parasite) benefits while the other species (the host) is harmed
Neuron
basic cell of the nervous system in vertebrates and most invertebrates
Dendrite
branches of neurons that receive signals from other neurons. Cells can have hundreds of dendrites but one axon
Myelin sheath
A greatly extended and modified plasma membrane wrapped around the nerve axon in a spiral fashion
Synapse
A junction between two neurons or between a neuron and a gland or muscle cell that allows the transmission of the electrical impulse between them
Action potential
reversal of electrical polarization of the membrane of a neuron of a muscle cell
Neurotransmitters
messengers of the nervous system. They are small molecules that carry information across synapses from a nerve cell to its neighboring cells
Capillaries
very tiny blood vessels
glycogen
A form of glucose, a main source of energy that your body stores primarily in your lower body and muscles
Disturbance
a temporary change in environmental conditions that causes a pronounced change in an ecosystem.
Mechanoreception
ability of an animal to detect and respond to certain kinds of stimuli
- Some mechanoreceptors are:
touch, sound, changes in pressure or posture
Nociception
Sensory mechanism that allows animals to sense and avoid potentially tissue damaging stimuli (pain perception)
Somatosensation
Sense of touch
Eustachian tube
controls the pressure within the middle ear making it equal with the air pressure outside the body
inner ear
in most vertebrates the inner ear is mainly responsible for sound detection and balance
Electromagnetic reception
sensing of magnetic fields by organisms
cornea
transparent part of the eye that refracts, or bends light
iris
thin, circular structure in the eye that controls diameter and size of eye pupils
lens
refracts light like cornea
Retina (cones, rods)
Light sensitive layer located in the back of the inner eye ball that contains light sensitive cells that can determine light, dark and color to assemble images to the world
migration
seasonal movement of animals from one region to another
Territoriality
Defense of an area
Exponential growth
it is the population growth rate of the number of organisms added in each generation increases as the population gets larger
Logistic growth
Population growth rate in which the growth decreases with increasing number of individuals until it becomes zero when the population reaches a maximum
Carrying capacity
The maximum number of individuals (of that species) that the environment can carry and sustain, considering it’s geography or physical features
Why are there usually no more than 4-5 consumer levels in an ecosystem?
Nutrients availability: in addition to energy, the availability of nutrients decreases with each trophic level. Nutrients such as nitrogen, phosphorus and potassium are essential for growth and reproduction of organisms, but they become increasingly scarce at higher trophic levels.
Trophic levels
the hierchal levels in an ecosystem that describe the feeding relationships among organisms
-Producers: Autotrophic organisms that convert sunlight, CO2 and H2O into organic matter through photosynthesis
- Primary consumers: The herbivores that eat producers
-Secondary consumers: The carnivores that eat the herbivores
-Tertiary consumers: The top predators that eat other carnivores
What types of things bioaccumulate and biomagnify, and what types of organisms are most impacted?
Things like heavy metals such as mercury, lead and calcium can bioaccumulate and biomagnify in certain ecosystems. Top level predators are the most impacted because those chemicals become more concentrated in their tissue overtime.
Compare the nitrogen, carbon, and phosphorus cycles. How do these elements cycle through the environment? How are the carbon, nitrogen, and phosphorus cycles linked to different forms of pollution and other environmental problems?
- Carbon is taken up by plants through consumption. It is also released into the atmosphere through respiration and decomposition. Human activities such as burning fossil fuels increases the amount of carbon in the atmosphere leading to climate change.
- Nitrogen is essential for growth of plants and is often limiting nutrient in ecosystems. Human activities such as fertilizer use and fossil fuel combustion have increased the amount of nitrogen in the environment leading to eutrophication (excessive nutrient levels in water bodies) and greenhouse gas emissions
- Phosphorus is cylced between rocks, soils, water bodies and living organisms. It’s released from rocks through weathering and is taken up by plants and animals through consumption. Human activities such as fertilizers has increased the phosphorus levels leading to eutrophication and algal blooms.
What causes sexual dimorphism in animal populations? Which sex is more likely to have weaponry and bright coloration?
Sexual dimorphism are physical difference between males and females of a species. Some causes are sexual selection which causes male competition. Natural selection where physical differences relate to different roles they play in environment. Enviornmental factors such as temperature and nutrition play a role in sexual dimorphism. Like how temperature of nest determines sex of offspring of some lizards. Lastly genetic factors for example in birds males have two copies of Z chromosomes and females have one Z and one W chromosome.
Of exponential and logistic population growth, which is most realistic for most populations?
Logistic population growth because it takes into account that there are limiting factors such as food, availability, predation and disease and assumes that as the growth rate of a population slows down as it approaches its carrying capacity.
What part of the body is responsible for sensing balance, and what is the mechanism?
The vestibular apparatus
How does color vision function, and how does human color vision compare to that of other animals? Are other animals colorblind? Why do some animals eyes “glow” in the dark?
Humans are trichromatic other mammals are dichromatic. Some animals can also ultraviolet which humans can not see. Some animals eyes glow in the dark due to the presence of a reflective layer in the back of the eye known as the tapetum lucidum which amplifies the amount of light that enters the eye
