Biology Mini Test 3

Front 1

what does mapping of motor neurons within the primary cerebral motor cortex imply about how the nervous system is able to control various skeletal muscles throughout the body?

Back 1

homunculus maps the brain and shows where each part of the brain moves what part

Front 2

what is muscle flexion

Back 2

a joint movement that decreases the angle between the bones that converge at the joint. For example, your elbow joint flexes when you bring your hand closer to the shoulder. Flexion is typically instigated by muscle contraction.

Front 3

what is muscle extension

Back 3

is the opposite of flexion, describing a straightening movement that increases the angle between body parts. When a joint can move forward and backward, such as the neck and trunk, extension refers to movement in the posterior direction.

Front 4

what are the three types of muscle that make up the human body

Back 4

cardiac, skeletal, and smooth.

Front 5

what are the basic cellular characteristics of each?

Back 5

Cardiac muscle cells, or cardiomyocytes, are the muscle fibers comprise the myocardium, the middle muscular layer, of the heart.

Skeletal muscle cells make up the muscle tissues connected to the skeleton and are important in locomotion.

Smooth muscle cellsare responsible for involuntary movement, like that of the intestines during peristalsis (contraction to propel food through the digestive system).

Front 6

muscle fiber

Back 6

contract when stimulated.

Front 7

myofibril

Back 7

any of the elongated contractile threads found in striated muscle cells.

Front 8

sarcomere

Back 8

a structural unit of a myofibril in striated muscle, consisting of a dark band and the nearer half of each adjacent pale band. are composed of long, fibrous proteins as filaments that slide past each other when a muscle contracts or relaxes

Front 9

tendon

Back 9

a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.the hamstring of a quadruped.

Front 10

what is the function of a neuromuscular junction?

Back 10

The function of the NMJ is to transmit signals from the motor neuron to the skeletal muscle fibre quickly and reliably, to ensure precise control of skeletal muscle contraction and therefore voluntary movement.

Front 11

how does the electrical action potential from the nerve get translated at the NMJ to stimulate muscle fiber contraction?

Back 11

through ACh, Acetylcholine

Front 12

role of acetylcholine

Back 12

has functions both in the peripheral nervous system (PNS) and in the central nervous system (CNS). In the peripheral nervous system, acetylcholineactivates muscles, and is a major neurotransmitter in the autonomic nervous system.

Front 13

function of t-tubule

Back 13

he function of T-TUBULES is to conduct impulses from the surface of the cell (SARCOLEMMA) down into the cell and, specifically, to another structure in the cell called the SARCOPLASMIC RETICULUM. ... But the primary function of the SARCOPLASMIC RETICULUM is to STORE CALCIUM IONS.

Front 14

function of sarcoplasmic reticulum

Back 14

The sarcoplasmic reticulum (SR) constitutes the main intracellular calcium store in striated muscle and plays an important role in the regulation of excitation-contraction-coupling (ECC) and of intracellular calcium concentrations during contraction and relaxation.

Front 15

function of ca2

Back 15

calcium floods into the cell and binds with troponin to open the active sites

Front 16

function of troponin

Back 16

is attached to the protein tropomyosin and lies within the groove between actin filaments in muscle tissue. In a relaxed muscle, tropomyosin blocks the attachment site for the myosin crossbridge, thus preventing contraction.

Front 17

function of tropomyosin

Back 17

is a protein involved in skeletal muscle contraction and that wraps around actin and prevents myosin from grabbing it. ... When the nervous system tells the muscle cell to contract, calcium is released. The calcium activates the troponin complex, which moves tropomyosin, and the muscle cell can contract.

Front 18

what protein filaments contribute to sarcomere structure

Back 18

thick and thin filaments

Front 19

z-disc or z-line

Back 19

The Z disk (or Z line) defines the boundaries of a muscle sarcomere. Two adjacent Z disks along the myofibril mark the boundaries of a single sarcomere. The Z disks are the attachment sites for the thin filaments. Therefore, from each Z disk, thin filaments extend to two neighboring sarcomeres

Front 20

m-line

Back 20

In striated muscle sarcomere, the M line is the attachment site for the thick filaments. The M line is in the center of the A band and, thus, it is in the center of the sarcomere.

Front 21

actin thin filaments

Back 21

: a myofilament of the one of the two types making up myofibrils that is about 5 nanometers (50 angstroms) in width and is composed chiefly of the protein actin—compare thick filament.

Front 22

myosin thick filaments

Back 22

pull the thin filaments toward the m-line after the cross bridge is formed

Front 23

what enzymatic activity does the myosin filament head have

Back 23

it forms a cross bridge

Front 24

what is the significance of the myosin power stroke

Back 24

its the actual muscle contraction

Front 25

what is a motor unit

Back 25

is made up of a motor neuron and the skeletal muscle fibers innervated by that motorneuron's axonal terminals. Groups of motor unitsoften work together to coordinate the contractions of a single muscle; all of the motor units within a muscle are considered a motor pool.

Front 26

how do motor units help us prevent fatigue when trying to sustain muscle tension

Back 26

Alternation of motor units allow some to rest between contractions, preventing fatigue.

Front 27

what is the advantage of turning on additional motor units when trying to lift an object

Back 27

so there is no fatigue and it allows the other motor units to rest.

Front 28

what is ecology

Back 28

the branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

Front 29

order of the biological hierarchy

Back 29

populations, communities, ecosystem, biome, and biosphere.

Front 30

population

Back 30

A group of organisms of one species that interbreed and live in the same place at the same time (e.g. deer population) (taxonomy)

Front 31

community

Back 31

An ecological unit composed of a group of organisms or a population of different species occupying a particular area, usually interacting with each other and their environment

Front 32

ecosystem

Back 32

made up of plants, animals, microorganisms, soil, rocks, minerals, water sources and the local atmosphere interacting with one another

Front 33

biome

Back 33

A large community of plants and animals that occupies a distinct region. Terrestrial biomes, typically defined by their climate and dominant vegetation, include grassland, tundra, desert, tropical rainforest, and deciduous and coniferous forests.

Front 34

biosphere

Back 34

s the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, geosphere, hydrosphere, and atmosphere.

Front 35

how does population density differ from population size

Back 35

population density is the number of people per unit of area, population size is the number of individual organisms in a population

Front 36

density-dependent definition and factors

Back 36

are factors whose effects on the size or growth of the population vary with the population density. There are many types of density dependent limiting factors such as; availability of food, predation, disease, and migration. However the main factor is the availability of food.

Front 37

density-independent definition and factors

Back 37

Any factor limiting the size of a population whose effect is not dependent on the number of individuals in the population. An example of such a factor is an earthquake, which will kill all members of the population regardless of whether the population is small or large.

Front 38

why are the characteristics of exponential growth vs. logistic growth of a population

Back 38

exponential looks like a J, Occurs when a population increases in size by a constant proportion from one generation to the next

logistic growth: occurs when the growthrate decreases as the population reaches carrying capacity. Carrying capacity is the maximum number of individuals in a population that the environment can support.May 30, 2015

Front 39

what is the name of the shape of the graph representing each type of growth

Back 39

exponential the shape is a J

logistic growth the shape is an S

Front 40

what are the factors that limit population growth

Back 40

Resources such as food, water, oxygen, and space availability, as well as predation, competition, and parasitism, place environmental limits on population growth.

Front 41

what is the carrying capacity of an ecosystem

Back 41

The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water, and other necessities available in the environment.

Front 42

what does a plateau in a logistic growth curve indicate about the health or reproduction of a population of a species

Back 42

that it stabilized

Front 43

what is a population crash

Back 43

a sudden decline in the numbers of individual members in a population, species or group of organisms

Front 44

what is a genetic bottleneck

Back 44

is a sharp reduction in the size of a population due to environmental events (such as earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide).

Front 45

what is the difference between interference competition and exploitive completion

Back 45

In exploitation competition, organisms use up resources directly. Once used, the resource is no longer available for other species to use. In interference competition, one organism prevents other organisms from using the resource. Of the two mechanisms, exploitation competition is the more common.

Front 46

symbiosis

Back 46

refers to a close and prolonged interaction between organisms of different species. Previously, the term is restricted to a mutualistic relationship wherein both organisms benefit from the interaction. In mutualism, the relationship between the two organisms is interdependent.

Front 47

mutualism

Back 47

is the way two organisms of different species exist in a relationship in which each individual benefits from the activity of the other.

Front 48

commensalism

Back 48

a relationship between individuals of two species in which one species obtains food or other benefits from the other without either harming or benefiting the latter.

Front 49

parasitism

Back 49

a non-mutual relationship between species, where one species, the parasite, benefits at the expense of the other, the host.

Front 50

keystone species

Back 50

is often a dominant predator whose removal allows a prey population to explode and often decreases overall diversity. Other kinds of keystone species are those, such as coral or beavers, that significantly alter the habitat around them and thus affect large numbers of other organisms.

Front 51

exotic invasive species

Back 51

they Fvck up the biome

Front 52

what are some strategies used by different species for protection/security from other species in the same area or territory

Back 52

camouflage , hiding, friendship

Front 53

what does a tightly linked population cycle represent

Back 53

inbreeding

Front 54

what are morphologic traits

Back 54

traits that are adapting, and changing based on their environment

Front 55

what is the gene pool for a species

Back 55

The total number of genes of every individual in an interbreeding population. Supplement. A large gene pool indicates high geneticdiversity, increased chances of biological fitness, and survival.

Front 56

genetic variation

Back 56

refers to diversity in gene frequencies.

Front 57

genetic recombination

Back 57

is the production of offspring with combinations of traits that differ from those found in either parent

Front 58

gene mutation

Back 58

is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people

Front 59

gene flow

Back 59

is the transfer of alleles or genesfrom one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies

Front 60

genetic drift

Back 60

variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.

Front 61

natural selection

Back 61

the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.

Front 62

what are the dangers of inbreeding over time in a population

Back 62

1. gene pool becomes less diverse

2. fertility and birth rates drop

3. infant mortality increases

4. growth and development rates slow

5. more susceptible to disease

Front 63

hardy-weinberg equilibrium equation

Back 63

p^2+2pq+q^2=1

p+q=1

Front 64

what do all the terms mean in the HW principle

Back 64

p is the variable for the frequency of the dominant allele

q is the variable for the frequency of the recessive allele

p² is the frequency of the homozygous dominant genotype (AA)

2pq is the frequency of the heterozygous genotype (Aa)

q² stands for the frequency of the homozygous recessive genotype (aa)

Front 65

what are the conditions for maintaining hardy weinberg genetic equilibrium

Back 65

Population must be very large.Population must be isolated from other populations (no immigration or emigration).No mutationsRandom matingNo natural selection (i.e. every individual has an equal chance of survival)

Front 66

how does microevolution of bacterial resistance to antibiotics develop

Back 66

In the case of antibiotic resistance, for example, a bacterial strain's huge population size and short generation time mean that natural selection acts quickly. In each bacterial generation, new mutations and gene combinations are generated. If any of these confer resistance to a drug to which the bacteria are exposed, natural selection will favor those gene versions. Over the course of many bacterial generations (a small fraction of a single human lifetime), the bacteria adapt to our defenses, evolving right out from under our attempts to rid ourselves of them.

Front 67

what causes insects to become resistant to pesticides

Back 67

Selection for resistance can occur if a small proportion of the insect population is able to survive treatment with insecticide. These rare resistant individuals can reproduce and pass on their resistance to the offspring

Front 68

how do microevolutionary events lead to cancer formation

Back 68

free radicals

Front 69

what is the difference between artificial selection and natural selection

Back 69

Natural selection and selective breeding can both cause changes in animals and plants. The difference between the two is that natural selection happens naturally, but selective breeding only occurs when humans intervene

Front 70

directional selection

Back 70

directional selectiona mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction

Front 71

stabilizing selection

Back 71

stabilizing selectiona type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value

Front 72

disruptive selection

Back 72

disruptive selection(or diversifying selection) a mode of natural selection in which extreme values for a trait are favored over intermediate values

Front 73

what are adaptions

Back 73

also called an adaptive trait, is a trait with a current functional role in the life of an organism that is maintained and evolved by means of natural selection.

Front 74

what is biological evolution

Back 74

is the process through which the characteristics of organisms change over successive generations, by means of genetic variation and natural selection

Front 75

how does divergent and convergent evolution relate to the acquisition of adaptions

Back 75

divergent is something coming in and changing it and convergent is something that was already there

Front 76

macro evolution

Back 76

major evolutionary change. The term applies mainly to the evolution of whole taxonomic groups over long periods of time.

Front 77

microevolution

Back 77

evolutionary change within a species or small group of organisms, especially over a short period.

Front 78

what is the theory of evolution

Back 78

The theory of evolution by natural selection, first formulated in Darwin's book "On the Origin of Species" in 1859, is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits.

Front 79

what does survival of the fittest mean

Back 79

the continued existence of organisms that are best adapted to their environment, with the extinction of others, as a concept in the Darwinian theory of evolution.

Front 80

what does form follows function mean

Back 80

is a principle associated with modernist architecture and industrial design in the 20th century. The principle is that the shape of a building or object should be primarily based upon its intended function or purpose.

Front 81

what does descent with modification mean

Back 81

is simply passing traits from parent to offspring, and this concept is one of the fundamental ideas behind Charles Darwin's theory of evolution

Front 82

what is an adaptive radiation

Back 82

the diversification of a group of organisms into forms filling different ecological niches.

Front 83

what is mass extinction

Back 83

The extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt.