Science Section Flashcards
What is a cell?
A cell is the smallest living functional unit of an organism.
What are cells composed of?
Living cells are
composed of approximately 60% water and vary in size and shape.
How is a red blood cell shaped?
Disc shaped. Biconcave discs.
how is a nerve cell shaped?
whereas nerve cells can be very long and have extensions on their main
body.
What does the nucleus do?
The nucleus contains the genetic information, or DNA (deoxyribonucleic acid), and controls
the activities of the cell.
What is the plasma cell membrane?
The plasma (or cell) membrane is known as a semipermeable membrane that separates the contents of the cell from the surrounding fluid
What does the interstitial fluid contain?
The interstitial fluid contains substances such as amino acids, sugars, fatty acids,
hormones, neurotransmitters, and salts
What does selectively permeable mean?
The term, selectively permeable (semipermeable),
refers to the selective nature of the plasma membrane. It contains pores and channels that
allow only particles of the right size or the right chemical nature to pass through. Additionally,
the plasma membrane contains receptors that bind with specific substances, thus allowing for
special entry or signals the cell to perform a certain activity.
What is the cytoplasm?
The cytoplasm is the fluid matrix found between the plasma membrane and the nucleus that
acts as scaffolding for the organelles.
What are the organelles
Organelles, or “little organs,” are specialized units in the
cell that perform certain functions.
What are the mitochondria?
The mitochondria are the locations for cellular respiration
or the conversion of food to energy at the cellular level. Thus the mitochondria are the sites of
energy production and of most of its ATP (adenosine triphosphate), which is a chemical the
cell uses to store and transfer energy within itself
What are ribosomes?
Ribosomes are the sites of protein
synthesis in the cell.
What does the rough ER do?
Rough ER, named for the fact that it has ribosomes on its surface,
serves to store and deliver the proteins made by the attached ribosomes.
What does the smooth ER do?
Smooth ER is free of
ribosomes and is found in a variety of cells. It performs varying functions in different cells,
including the storage of enzymes and minerals and the folding of proteins. It is thought to be
involved in the detoxification of chemicals and the metabolism of fats.
What does the golgi complex do?
The Golgi complex
modifies and packages proteins destined for use in the cell or for export from the cell.
What do lysosomes do?
Lysosomes are sacs that contain strong digestive enzymes. These sacs are responsible for
digesting waste and cell structures that are malfunctioning or dead.
How can plant cells be distinguished from animal cells?
Plant cells can be distinguished from animal plants by the presence of a surrounding cell wall
and chloroplasts.
What does the cell wall do?
The cell wall is essential for protection of the cell, the maintenance of the
shape, and water balance.
What are chloroplasts?
Chloroplasts contain chlorophyll, which is necessary for
photosynthesis
What are vacuoles?
Plant cells also often have large vacuoles, which are compartments in the
cytoplasm that act as places for secretion, excretion, and storage
Why do cells divide?
Cells divide for a number of reasons: growth, repair, and the production of gametes (sperm or
egg cells).
What is the most important part of cell division?
The most important result of cell division is that the genetic material, DNA, is
transmitted to the offspring.
What is chromatin?
When a cell is not dividing, DNA is found in the form of loosely structured
chromatin,
What is chromosomes?
but when a cell is dividing, the DNA is seen in condensed rod-shaped bodies
called chromosomes.
What is mitosis?
When cells divide, the appropriate amount of genetic material must be passed on to the new
daughter cells. In somatic (non-reproductive) cells, the new cells are identical copies of the
parent cells. This is achieved by a doubling of the chromosomes prior to division. This type of
cell division is referred to as mitosis, and it is useful in the growth and repair of our bodies.
What are gametes?
These reproductive cells contain half
of the normal number of chromosomes so that the zygote, the cell created by the union of a
sperm and egg, contains a full set of chromosomes, half from each parent.
What is meiosis?
This type of
division, or meiosis, consists first of a doubling of chromosomes and then two subsequent
divisions. Thus the products are four daughter cells, each with half the normal number of
chromosomes.
What is an organ?
Various tissues are combined into an organ, which performs a specialized function in the
body
What are the types of muscle tissues?
(skeletal, cardiac, and smooth)
What are the types of nervous tissue?
Neurons
What are the types of epithelial tissue?
(skin, the lining of organs)
What are the types of connective tissue?
(cartilage, blood, fat, bone)
What is an organ system?
organ system, which is made up of a number of organs
working together to carry out a major function
What is an organism?
The highest level of organization is the organism itself, such as the human body.
What is evolution?
In 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection,
which presented evidence for evolution, a theory regarding the processes that have produced
the biological diversity we see today
What is natural selection?
. evolution occurs by means of natural selection, the process by which the traits that
promote or enhance an organism’s ability to survive and reproduce are passed on to
following generations.
What is adaption?
In this struggle, the individuals best suited to their environment survive (“survival of the fittest”)
and pass on those traits to their offspring. This is called adaptation, the evolutionary process
of an organism to survive in a given environment.
Why does natural selection occur?
For natural selection to occur, organisms must have variations, some of which give the
individuals having them an advantage in the struggle for survival. The struggle for survival
occurs because each generation of a species produces more offspring than can survive.
What is the fossil record?
There is evidence supporting the theory of evolution, such as the fossil record, which consists
of remnants or traces of organisms from past geologic ages
What are vertebraes?
vertebrates (animals with backbones)
What is biogeography ?
(the geographical distribution of plants and animals),
What is comparative anatomy?
The comparison of organisms structures.
What is comparative embryology? the comparison of organisms’ embryos
the comparison of organisms’ embryos
What is molecular biology?
Biology at the molecular level
What is taxonomy?
In taxonomy (the study of scientific classification), taxonomists group species according to their similarities and differences. They are classified in a hierarchical system in which each level is more specific than the one above it
What are kingdoms?
The broadest units of
classification are the kingdoms,
What are the kingdoms?
of which there are five: animal, plant, monera (bacteria),
protist (protozoa, algae, and some molds), and fungi (molds, mushrooms, yeasts, and the
like)
What are the classifications used to identify an organism?
The next six classifications become increasingly specific: phylum, class, order, family,
genus, and species.
What is active transport?
Active transport involves the use of energy in the form of ATP to move
substances across the membrane
What is passive transport?
Passive transport does not require energy and makes use
of diffusion and filtration.
What is diffusion?
In diffusion, particles move in a random manner, spreading evenly
throughout an available space and moving from regions of high concentration to those of low
concentration
What is osmosis?
A specific type of diffusion is that of water, or osmosis. Water moves from an area of high water concentration (or low particle concentration) to an area of low water concentration (high particle concentration)
What is isotonic?
When the solute concentration of the water is
the same as that inside the cell, the solution is said to be isotonic. Thus, the amount of water
that leaves the cell and the amount that enters it are equal.
What is hypertonic?
When the solute is more
concentrated outside the cell than inside it, the solution is hypertonic. As a result, the cell shrinks.
What is hypotonic?
If the solute concentration outside, the cell
is lower than that inside the cell, the solution is hypotonic. Water flows into the cell (again
high-water/ low-particle concentration to low-water/high-particle concentration). If the flow
continues long enough, the cell bursts
What is filtration?
Filtration is the movement of water and solutes through the membrane by fluid, or hydrostatic,
pressure.
What are autotrophs?
Autotrophs are organisms that produce their own food from inorganic substances (i.e. plants)
What are heterotrophs?
Heterotrophs, or consumers, on the other hand, obtain their food by consuming plants or
other animals.
What are secondary consumers?
Secondary consumers are carnivores (meat eaters) or omnivores that eat
herbivores.
What are herbivores?
Plant eaters
What are omnivores?
Plant and meat eaters
What are carnivores?
meat eaters
What are tertiary consumers
Tertiary consumers are carnivores that eat other carnivores or omnivores.
What are primary consumers?
Herbivores, omnivores.
What are the trophic levels of an ecosystem?
These divisions, which are made on the basis of how the organism meets its nutritional needs,
make up the trophic levels of an ecosystem.
What are the producers?
The autotrophs are the most important trophic
level in the ecosystem and are known as producers;
What is a food chain/food web?
The path along which food is transferred from level to level is called a food chain, and the interrelationship of many food chains is called a food web.
What are the functions of the decomposers/what are they?
An important role in an ecosystem is played by the decomposers, such as bacteria and fungi,
which consume nonliving organic material and release inorganic material.
What are factors that affect an ecosystem called?
Factors that affect an ecosystem are classified as biotic or abiotic.
what are biotic factors?
Biotic factors include the
living parts of the ecosystem,
What are abiotic factors?
and abiotic factors are nonliving influences, such as
temperature, humidity, or soil composition.
What is parasitism
parasitism (in which one species benefits and the other species is harmed, such as a tapeworm in a human host)
What is commensalism
commensalism (in which one species benefits
and one is unaffected, such as a remora and shark
What is mutualism
mutualism (in which both species
benefit, such as lichen, which is made up of a fungus and an alga and is found on a tree or
rock)
What is a biosphere?
a biosphere is the entire portion of our planet that is inhabited by living
things in a variety of ecosystems and communities
What are biomes?
Within the biosphere are groups of
ecosystems that are common to the various types of geographical areas. These geographical
areas are called biomes
What are tundras?
Tundras are characterized by very cold temperatures and high altitude. The conditions
allow shrubs and bushes to grow, but no trees.
What are deserts?
Deserts have little precipitation and are more arid than all of the other biomes.
What are tropical rain forests?
Tropical rain forests typically have a relatively constant temperature (68°F-90°F),
constant daylight length throughout the year, high humidity, and abundant rain (200-
400 cm/year). These forests are known for their biodiversity, having more species than
any other area of the world. Trees grow very tall and there is great competition for light.
Little light reaches the forest floor.
What are deciduous forests?
Deciduous forests are usually found in the temperate, mid-latitude regions of the
world, where the air contains enough moisture to support the growth of large trees.
Deciduous trees, such as oaks and maples, drop their leaves during the dry months.
The temperatures in this biome can range widely from season to season.
What are Coniferous forests
Coniferous forests (taigas) are found at high and cool elevations, where the seasons consist of short summers and long, chilly winters. These areas are characterized by conifers, such as pine, and firs, which do not shed their leaves in the cold, dry months.
What is photosynthesis?
To produce their own organic molecules from inorganic molecules in the environment,
autotrophs use the process called photosynthesis.
What does chlorophyll do?
In this process, the pigment chlorophyll,
which is located in the chloroplasts of plant cells, absorbs light energy. This energy, in turn,
drives the synthesis of food molecules
What is a cuticle plants?
The stems and leaves of most plants are covered by a cuticle, which is a waxy layer that helps
prevent water loss through evaporation.
What are stomates?
Additionally, the leaves have stomates, which are
pores on the lower surface of the leaves that allow carbon dioxide to enter and oxygen to be
released during photosynthesis without losing too much water.
What are angiosperms?
The flower in flowering plants,
or angiosperms, is responsible for reproduction
What are the sepals?
The sepals encase the flower
before it blooms.
What are the petals?
the petals are useful in attracting pollinators. In the center of the petals
are the stamen and pistils
What are the stamen?
The stamen consists of the filament, which supports the anther, where pollen is produced.
What does the pistil consist of?
The pistil consists of the stigma (which receives pollen), the style (which leads to the ovary), and the ovary (which contains the ovules and where fertilization
occurs).
How is fruit made?
After fertilization, the ovules within the ovary develop into seeds. The walls of the
ovary thicken to protect the seed and this thick fleshy protective layer is what we know and
love as fruit.
What are genes?
All living things possess a set of instructions (genes) that determines the characteristics of an
organism.
Where are genes?
On chromosomes
What is the law of dominance?
In observing pea plants, Mendel observed that, when individuals with contrasting traits are
crossed, one trait, called the dominant trait, is expressed, and the other trait, called the
recessive trait, is masked. This is the law of dominance
What does phenotype mean?
The phenotype, or appearance of the plants
What does homozygous mean?
An individual with two identical genes for a
trait is called purebred, or homozygous
What does heterozygous mean?
For example, if a tall plant (TT) is crossed with a short plant (tt), the result is 100%
heterozygous (Tt) offspring, containing one allele for tall and one for short
What is the law of segregation?
The law of segregation tells us that when two of these hybrids (heterozygotes) are crossed,
the hidden trait becomes segregated and appears in 25% of the offspring.
What is the law of independent assortment?
The law of independent assortment tells us that genes on different chromosomes are inherited independently of each other.
How many chromosomes do humans have?
46
What are autosomes?
Non sex chromosomes
What are sex linked traits?
For some traits, the genes are found only on the X chromosome, but not on the Y, and these traits are called sex-linked traits.
What is a nucleotide made of?
Each nucleotide is composed of a phosphate group (PO4), a five-carbon sugar called deoxyribose, and a nitrogenous base.
What is the double helix?
The nucleotides form long chains, which are joined to form a double helix.
What does guanine always pair with?
cytosine (C)
what does adenine always pair with?
Thyamine
What happens during replication of DNA ?
During replication, the DNA strand opens at the base pairs. Free (or unattached) nucleotides are incorporated into the unzipped portion of the DNA, so that
complementary base pairs join to form two exact duplicates
What is transcription?
The process of forming m-RNA according to the information contained in the DNA molecule is called transcription
How does transcription differ from translation?
RNA differs
from DNA in that it is single stranded, has the sugar ribose in place of deoxyribose, and
replaces thymine with uracil.
What is a light microscope?
In a light microscope, light is
first passed through a specimen and then through a glass lens, which bends light in such a
manner that an image is magnified
What is an electron microscope?
The electron microscope, which sends a
beam of electrons through a specimen, can be used to examine structures too small to be
seen through a light microscope.
How much can a light microscope magnify?
The light microscope can magnify specimens up to 2,000
times,
How much can a electron microscope magnify?
whereas the electron microscope can magnify them up to 2 million times
How much can the compound microscope magnify?
The compound microscopes you may have used in school usually magnify around 400 times,
under high power
What are variables?
During an experiment, we are often looking for data
on variables, which are measurable factors or qualities that change during an experiment.
What is an independent variable?
An independent variable is one that is changed by the experimenter.
What is the dependent variable?
The variable that changes in response to the independent variable is called the dependent variable
Where is the independent and dependent variable plotted on a graph?
When we represent data in the form of a graph, the independent variable is
always plotted on the x-axis and the dependent variable on the y-axis.
What is mechanical digestion?
breaking food into smaller pieces
What is chemical digestion?
chemical digestion (breaking nutrients into small molecules)
What is hydrolysis?
The process by
which chemical digestion occurs is called hydrolysis (splitting molecules by adding water).
What are the functions of enzymes in digestion?
Chemical digestion is sped up by the action of digestive enzymes (hydrolases
What is the alimentary canal?
Humans, as opposed to simpler animals, such as jellyfish, have a digestive system that is composed of a
tube that extends between two openings: the mouth and the anus. This tube,
called the alimentary canal
What are the accessory glands of the digestive system?
(liver, gallbladder, and pancreas).
What is the surface area (digestive system)
Food enters through the mouth, where it is chewed (mechanical digestion), increasing the
surface area, which makes it easier to both swallow and digest.
What do the salivary glands do?
The presence of food also
stimulates the salivary glands to release saliva, which contains an enzyme called amylase.
What does amylase do?
Amylase breaks down starches into smaller carbohydrate molecules (monosaccharides and
disaccharides)
What is the function of the epiglottis?
While swallowing, the top of the
windpipe is covered by the epiglottis to prevent food from entering the respiratory system.
What is peristalsis?
From the esophagus, the food is passed to the stomach by muscular contractions called
peristalsis.
What does the lining of the stomach do for digestion?
The lining of the stomach releases gastric juice, which is made up of hydrochloric acid and
proteases (protein digesting enzymes)
What is chyme?
The smooth muscles of the stomach mix the partially digested food and the result is a liquid called chyme
What does the pyloric sphincter do?
Chyme is released to the small intestine in a series of small portions through the pyloric sphincter.
Where does most of the digestion take place in humans?
Most of the digestion of food takes place in the small
intestine, which can be up to 6 meters long in humans. The small intestine is the major site not only for digestion but also for the absorption of
nutrients into the bloodstream. Digestive enzymes are secreted by intestinal glands.
What does the liver do in terms of digestion?
The liver produces bile, a substance stored and concentrated in the gallbladder, which helps in the
breakdown of fats.
What does the pancreas do in terms of digestion?
The pancreas supplies a number of enzymes needed for digestion.
what do the villi do?
To facilitate absorption, the small intestine is lined with villi, which greatly increase the intestinal
surface area for the absorption of the end products of digestion into the blood and lymph.
What happens to the undigested food?
Undigested food is moved to the large intestine, or colon, which is responsible for
reabsorbing water that has entered the alimentary canal.
Where is the waste stored?
Waste, or feces, moves along the colon by peristalsis, becoming increasingly solidified and is ultimately stored in the rectum until egestion (elimination from the body).
How does diarrhea and constipation occur?
. Diarrhea is a result of peristalsis moving feces
through the colon too quickly so that water is not reabsorbed, whereas constipation results
from too little peristalsis and thus too much reabsorption of water
What is circulation?
Circulation is the internal transport of blood and lymph throughout the body, which allows for
the exchange of gases, the absorption of nutrients, and the disposal of waste.
What is the circulatory system made up of?
The circulatory system is made up of the cardiovascular and lymphatic system, which function together to
achieve these goals.
What is the cardiovascular system made up of?
The cardiovascular system in humans is made up of the heart, blood vessels, and blood.
What are the four chambers of the heart?
Two atria, two ventricles.
What do the atria do?
: two atria (singular: atrium), which receive blood
What do the ventricles do?
ventricles, which pump blood to the body
Where does the blood from the body enter the heart?
Blood enters the right atrium from the upper and lower body through veins called the
superior vena cava and the inferior vena cava.
What is the atrioventricular valves functions?
From there, it passes through an atrioventricular valve into the right ventricle (valves
prevent backflow when ventricles contract).
What do the pulmonary arteries do?
The right ventricle pumps blood through the semilunar valve into the pulmonary arteries,
which carry the blood to the lungs. This blood is deoxygenated and becomes oxygenated
in the lungs where gas exchange occurs.
What do the pulmonary veins do?
Newly oxygenated blood leaves the lungs via the pulmonary veins, which returns blood to
the left atrium.
What does the left ventricle do?
From there, it passes through another atrioventricular valve to the left ventricle.
Muscular contractions of the left ventricle pump blood through the aorta to all parts of the
body.
What is systole?
When the heart
contracts, the pressure increases (systole),
What is diastole?
When the heart relaxes, the pressure decreases diastole
What are the three ways blood circulates?
There are three ways blood circulates: coronary circulation, (circulation of
blood to the heart ), pulmonary circulation (circulation of blood through the lungs), and
systemic circulation (circulation throughout the body).
What is blood?
Interestingly, blood is considered a type of connective tissue that is made up of variety of cells
suspended in a liquid called plasma.
What is the composition of blood?
Red blood cells, white blood cells, and
platelets make up 45% of whole blood, whereas plasma, which contains proteins, ions,
hormones, and gases, makes up the other 55%
What do red blood cells do?
Red blood cells, or erythrocytes, are
responsible for transporting oxygen, and they do not have nuclei or mitochondria.
How many molecules of hemoglobin per red blood cell?
To suit their
main function of transporting oxygen, red blood cells are small and thin (to allow for diffusion),
and each cell contains approximately 250 million molecules of hemoglobin, an oxygen carrier.
Why is iron necessary in our diets?
Hemoglobin is an iron-rich globular protein, which explains the need for iron in our diets.
What do white blood cells do?
White blood cells, or leukocytes, are less abundant than red blood cells and are involved in
host defense. Not surprisingly, an infection is indicated when the number of white blood cells
exceeds the normal concentration.
What do platelets do?
Platelets, also found in plasma, are pieces of cells that are important in blood clotting.
What do lymph capillaries do?
As blood passes through the capillary vessels of the circulatory system, fluid and proteins can
leak out into the interstitial space. This lost fluid diffuses into lymph capillaries, which are
found throughout the cardiovascular system, and thus enters the lymphatic system. Inside the lymphatic system, the fluid, or lymph, returns to the circulatory system
What do lymph nodes do?
Lymph nodes are special pockets in the lymphatic system where the lymph is filtered. White
blood cells are present in these nodes to attack bacteria and viruses that may be present in
the fluid. This is why swollen and tender lymph nodes are usually a sign of an infection.
What are the three kinds of blood vessels?
There are three kinds of blood vessels: arteries, veins, and capillaries
What are the functions of arteries?
Arteries transport blood away from the heart. Because they carry blood at relatively high pressure, they are muscular. We feel a pulse in the arteries
What are the functions of veins?
Veins transport blood to the heart, and they contain valves to prevent the backflow of blood as it returns to the heart.
What are the functions of capillaries?
Capillaries are tiny blood vessels that
connect arteries and veins. It is through the capillary walls (only one cell thick) that nutrients
and oxygen leave the blood to enter the interstitial space and tissue cells and waste products
and carbon dioxide leave the tissue to enter the blood.
What is the order of taking a breath?
Air enters the respiratory system through the nasal cavities, which lead to the pharynx, then to the larynx, then the air travels to the trachea, or windpipe, which branches into two main bronchi, which lead to the lungs. Inside each lung, the branching continues, creating thinner and thinner tubes called bronchioles, and at the end of these bronchioles are alveolus.
What is an alveolus?
An air sac. These thin and permeable air sacs are the functional units of the lung.
what does the diaphragm do in terms of respiration?
This involves the muscular movement of the diaphragm (a sheet of muscle lining the bottom of the
thoracic cavity) and of the rib cage, which raises and lowers the pressure in the chest cavity.
What is cellular respiration?
Cellular respiration is the process by which we get energy from the food that we eat.
What is aerobic respiration?
Aerobic respiration occurs when oxygen is present,
and it is the opposite process to that of photosynthesis
What is anaerobic respiration?
If oxygen is not present, anaerobic respiration occurs, which is less efficient, producing a lower amount of
ATP.
What is the production of lactic acid a result of?
. Lactic acid, which is produced during anaerobic respiration, is a cause of sore muscles
after strenuous exercise.
What is anaerobic respiration called in yeast, and why
Anaerobic respiration in yeast is called fermentation, producing
ethanol rather than lactic acid.
What does the nervous system do?
The nervous system directly regulates body functions and responds to environmental stimuli.
What is the functional unit of the nervous system?
The functional unit of the nervous system is the neuron
Why do neurons at rest have an electrical potential?
At rest, neurons have an electrical potential due to differences in sodium and potassium ion concentrations across the cell membrane
What is an impulse?
Generally, an impulse is generated when the dendrites of a neuron are stimulated by the environment or by another neuron.
How does the impulse travel?
The impulse travels from the cell body along the axon until it reaches the ends (axon terminals)
What does the impulse traveling trigger?
This triggers the release of neurotransmitters, which travel across synapses and may trigger other neurons or muscles.
What do myelin sheaths do in terms of impulse traveling
Axons may have myelin sheaths, which help transmit
impulses faster.
What are the three types of neurons?
Sensory neurons, interneurons, motor neurons.
What do sensory neurons do?
Sensory neurons transmit impulses from sense organs and receptors.
What do inter neurons do?
Interneurons make up the brain and spinal cord.
What do motor neurons do?
Motor neurons carry impulses from interneurons to skeletal and visceral muscles and glands.
What are nerves?
Nerves are groups, or bundles, of the axons of sensory and/or motor neurons.
What are the two subsystems of the nervous system
Central nervous system, peripheral nervous system.
What does the central nervous system include
The central nervous system (CNS) includes the brain and spinal cord.
What does the peripheral nervous system include
The peripheral nervous system (PNS) includes the nerves and sense receptors.
What is the PNS responsible for?
The PNS is responsible for transmitting information to and from the CNS.
What is the CNS responsible for?
The CNS is responsible for processing information.
What are the two branches of the PNS?
e somatic branch
autonomic branch.
What is the somatic branch concerned with?
the somatic branch is concerned with the external environment
What is the autonomic branch concerned with?
autonomic branch is concerned with the
internal environment, such as the digestive system.
What does a reflex arc do?
A reflex arc carries out simple, quick, and automatic responses to certain stimuli. Reflex
actions are commonly defensive and do not necessarily involve the brain.
Where is the spinal cord located?
The spinal cord extends from the brain downward and is enclosed by the bones of the vertebral column, or spine
What do openings between the vertebrae allow for?
Openings between the vertebrae allow peripheral nerves to join with the spinal cord.
What does the spinal cord do?
The spinal cord passes messages to and from the brain, and acts as the center
for reflex actions.
What can damage to the spinal cord result in?
Damage to the spinal cord may result in paralysis and may be permanent.
Where is the brain and what are its subdivisions?
The brain is protected and enclosed within the cranium and is divided into three areas: The cerebrum, the cerebellum, and the medulla (Brain stem)
What is the cerebrum responsible for?
The cerebrum makes up the largest portion of the human brain and is the site of complex
and high-level thinking. Conscious and voluntary actions are controlled here, as are other
functions such as speech, vision, hearing, and memory.
What is the cerebellum responsible for
The cerebellum is located below and behind the cerebrum. It is responsible for muscular
coordination and balance.
What does the brain stem do
The brain stem, or medulla, controls basic homeostatic functions such as body
temperature, blood pressure, and breathing.
What is an important function of the endocrine system>
An important function of the endocrine system is to maintain homeostasis
What is homeostasis?
homeostasis, which is the body’s
way of keeping its internal environment stable by means of secretions from the endocrine
glands.
Why are endocrine glands also called ductless glands?
These glands are also called ductless glands because they secrete hormones directly
into the bloodstream
What are hormones?
Hormones are chemicals that act as messengers and that help control
the important processes of growth, metabolism, reproduction, osmotic balance, and
development
How do hormones work?
Most hormones work by binding to their target cells by means of a receptor and
influencing the activity of the cell.
How are hormones activated?
Hormones are usually activated by some type of stimulus
What does the thyroid gland do?
regulates·
metabolism
What does the parathyroid gland do?
regulates calcium
metabolism
What does the thymus gland do and where is it located>
supports immune
system in young
children and on chest
What does the adrenal gland do?
so-called fight-orflight hormone;
regulate water
balance, blood
pressure
What does the Isles of
Langerhans do and where is it located?
control storage of
sugar in liver and
blood level of sugar and pancreas
What does the testes do and where is it located?
Located : in the scrotum
male secondary sex
characteristics
What do the ovaries do and where are they located
pelvic
female secondary sex
characteristics,
menstrual cycle
What is the musculoskeletal system composed of?
The musculoskeletal system is composed of bones, connective tissue, and muscle.
What are the functions of the musculoskeletal system?
the support and protection of the internal organs, and movement
Where are blood cells made?
blood cells are made in the red marrow of the long bones
What are osteocytes?
Bone contains osteocytes, which produce a hard, calcium-rich extracellular matrix.
How many bones in the body?
206.
What does the axial skeleton consist of?
The axial portion of the
skeleton consists of the skull, vertebrae, ribs, and sternum.
What does the appendicular skeleton consist of?
The appendicular skeleton is made
up of the bones of the shoulders, arms, pelvis, and legs.
What do joints do?
Joints connect the bones of the skeleton
What are sutures?
Sutures are immovable joints that join the bones of
the skull, permitting growth but no movement.
What type of joints do the shoulders and hips have?
ball-and-socket joints
What type of joints do the elbow/knee have?
Hinge joints
What type of joints do the wrists have?
Sliding and gliding joints
What is osteoarthritis
a degenerative bone and joint disease
What is Rheumatoid arthritis
Rheumatoid arthritis (a degenerative joint disease caused by an autoimmune response)
What is osteoporosis
Osteoporosis (a disease caused by calcium loss often found in older people, especially
postmenopausal women)
What do ligaments do?
Ligaments connect bones to other bones.
What do tendons do?
Tendons connect muscles to bones
What does cartilage do in the skeletal system?
Cartilage cushions bones at the joints.
What are the three types of muscles?
Cardiac, smooth, skeletal
What is cardiac muscle and where is it found?
Cardiac muscle is found only in the heart and is involuntary.
What is smooth muscle and where is it found?
Smooth muscle also involuntary, is found in the internal organs of the digestive tract
and in blood vessels.
What is skeletal muscle?
. Skeletal muscle is also called striated muscle due to the microscopic appearance of
the individual muscle cells or fibers. Skeletal muscles move bones and are responsible
for voluntary movements. Skeletal muscles, attached to bones by tendons, move the
bones when they contract and thereby shorten.
Which muscle is often found in opposing pairs?
Skeletal
What is the flexor of a muscle?
In such a pair, one muscle, the flexor,
bends or moves a limb away from anatomical position.
What is the extensor of a muscle?
The other muscle, the extensor, returns
the limb to the anatomical position
Give an example of the body using a flexor/extensor muscle
The biceps muscle (a flexor) and the triceps muscle (an
extensor) of the upper arm are good examples of this.
What are the kidneys?
The kidneys are the principal excretory organs of the body
What is the functional unit of the kidney?
nephron
What is the outer and inner parts of the kidney called?
The outer portion of
the kidneys is the renal cortex and the inner portion is called the renal medulla.
What does the nephron include?
glomerulus, Bowman’s capsule, the
proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule.
What is urine?
The concentrated mixture of wastes that is left in the tubules forms urine
What are the functions of ureters?
Urine which enters the
collecting tubules to the ureters, The ureters transport urine to the urinary bladder for storage.
What does sexual reproduction start with?
Sexual reproduction starts with the fusion of two gametes (sperm and egg) to form a zygote
(united sperm and egg).
What is a monoploid/haploid?
Each gamete is monoploid (or haploid), containing half of the normal
complement of chromosomes
What is diploid?
When the zygote is created from the union of a sperm and an
egg, it contains the full complement of chromosomes and is diploid.
What are the external reproductive organs in the male?
In the male, the genitalia, or the external reproductive organs, are the penis and the scrotum
What are the internal reproductive organs in the male?
The internal reproductive organs consist of the testes, the primary male
reproductive organs
What do the testes contain?
The testes contain seminiferous tubules, where sperm form, and interstitial cells, which produce male sex hormones such as testosterone.
What does the epidymis do?
When sperm is
produced in the seminiferous tubules, it then travels into the epididymis, which is made of
coiled tubes that store sperm while they mature
What happens to the sperm during ejaculation?
The sperm are sent through the epididymis
during ejaculation into the vas deferens to the ejaculatory duct to the urethra.
What are the primary reproductive organs in the femael?
The ovaries which produce both eggs and
the hormones progesterone and estrogen
What is a oocyte
Inside the ovaries are ovarian
follicles, each of which contains an immature egg called an oocyte
What is ovulation?
As the egg develops, the
follicle also matures and enlarges. When fully mature, the follicle releases the egg in the stage
called ovulation, which occurs approximately every 28 days
What is the fallopian tubes function?
The egg then travels through the
fallopian tubes, where it can be fertilized.
What is the endometrium?
If fertilized, the egg travels to the uterus, where it
becomes implanted in the uterine lining, the endometrium, and remains there for the rest of its
development.
What happens when the egg is not fertilized?
the endometrial lining
is shed, and it thickens again in preparation for the possibility of implantation in the next cycle.
The shedding is a process known as menstruation.
What happens when the egg is fertilized?
If fertilization occurs, the developing embryo implants itself in the uterus, where it develops
during its gestation period of nine months.
How is the placenta formed?
Tissues of the embryo and the mother grow together
to form the placenta
What does the placenta do?
The blood of the embryo and mother are never directly connected, but nutrients and oxygen from the mother and wastes from the embryo are exchanged through the
placenta
How is the fetus connected to the placenta?
The fetus is connected to the placenta by the umbilical cord.
What does the cornea do?
At the front of the eyeball, the transparent cornea allows light to enter the eye
What does the iris do, where is it located?
Behind the cornea is the iris, which not only gives our eyes color, but also changes in size,
regulating how much light is allowed to enter the pupil, which is in the middle of the iris.
What do the lenses do?
The lens focuses light onto the retina, its shape changed by attached muscles.
What is the retina?
The retina is the innermost layer of the eyeball and contains two types of photoreceptor cells.
What are the two types of photoreceptor cells in the retina?
Rod cells / Cone cells
What do cone cells do?
Cone cells allow us to distinguish colors in the day
What do rod cells do?
are
sensitive to light, distinguish between black and white, and allow us to see at night.
What does the optic nerve do?
When they are stimulated by light, the photoreceptor
cells transmit the information along the optic nerve to the brain.
What is the ear responsible for
The ear is responsible not only for hearing, but for balance as wel
What does the outer ear do?
The outer ear collects sounds and transmits them to the tympanic membrane
What is the tympanic membrane?
Seperates outer ear from middle ear
What does the middle ear do?
In the middle ear, the vibrations produced by sound are transmitted through three small
bones (ossicles):
What are the three bones in the middle ear?
Malleus, incles and stapes
What makes your ears pop?
The middle ear is also connected to the
Eustachian tube, which opens into the pharynx. This tube equalizes the pressure
between the middle ear and the atmosphere, sometimes making your ears “pop.”
What does the inner ear do?
The inner ear has many channels containing fluid that moves in response to your
movement or to sound.
What is the cochleas function?
Sound coming into the inner ear moves the fluid, causing the cochlea, a part of the inner ear, to transduce (or convert) the movement into signals or
action potentials.
What are the semicircular canals involved in?
The semi-circular canals are involved
in balance.
What is chemistry?
Chemistry is the both the study of the properties of matter, which is a substance that has mass
and energy, and occupies space, and the ways in which the properties of matter interact,
combine and change.
What is matter?
matter, which is a substance that has mass
and energy, and occupies space
What is a substance?
A substance is any material all samples of which have the same
composition and properties (a mixture is not a substance).
What is an atom?
An atom is the smallest
unit of an element that still retains the properties of that element.
What are the three types of subatomic particles?
Protons, neutrons and electrons
What are protons?
Protons carry a positive charge and are found in the nucleus of an atom.
What are neutrons?
Neutrons are neutral and are also found in the nucleus.
What are electrons?
Electrons carry a negative charge and are found outside the nucleus and arranged according to their energy level.
How is an element identified?
An element is identified by its symbol and its atomic number
What is the atomic number?
The atomic number is equal to the number of protons found the nucleus of each of its atoms
What is the mass number?
The mass number of an atom,
which is the number at the bottom of the symbol is equal to the number of nucleons (protons + neutrons) in its nucleus. To find the number of protons in an atom, just look at its atomic number.
How do you find the number of neutrons in an element?
To find the number of neutrons in an
atom, subtract the atomic number from the mass number of the element
What are isotopes
Atoms of the same element (with the same number of protons)
that contain a different number of neutrons are called isotopes
What is the atomic mass?
The atomic mass of an element is a weighted average of the mass numbers
of all naturally occurring isotopes of the element.
What are radioisotopes?
ome isotopes are radioactive; these are
called radio-isotopes
What happens when the number of electrons does not equal the protons?
When
the number of electrons does not equal the number of protons, the atom carries a charge.
What are charged atoms called?
Charged atoms are called ions
What is a cation?
An ion with a positive charge is called a cation. `
What is an anion?
n ion with a negative charge is called
an anion; it has more electrons than protons.
What are electrons found in the outermost shell called?
Electrons found in the outermost
energy level are called valence electrons
What is the maximum number of valence electrons in the outer ring?
8
What is the periodic table?
The periodic table (Figure 21) contains all the known elements, arranged in horizontal rows
called periods, in order of increasing atomic number.
What do the groups of the periodic table contain?
The columns, or groups, on the table
contain elements with similar properties because of their similar electron configurations
What is on the periodic table of elements from left to righ?
From left to right across a period, the elements move from metals on the left-hand side of the chart
to metalloids and finally to nonmetals on the right-hand side
What are noble gases?
The last group (18) on the right is
the noble gases, which have full valence shells; some of them can form compounds with other
elements
How does an atom become more stable?
An atom becomes more stable as its electron configuration becomes like that of a noble gas.
What does the octet rule state?
The
octet rule states that atoms tend to combine in such a way that they each have 8 electrons in
their valence shells, giving them the same electronic configuration as a noble gas.
How can atoms achieve this stability?
Atoms can
achieve this stable configuration by gaining, losing, or sharing electrons.
What is an ionic bond?
Positive and negative ions attract each other forming an ionic bond.
What are the chemical compositions of ionic compounds?
Ionic
compounds have high melting and boiling points, but dissolve in polar solvents such as water.
What is a covalent bond?
Some atoms form molecules by sharing pairs of electrons, forming what is known as a
covalent bond
What is a nonpolar covalent bond?
When two atoms share electrons equally, as in Cl2, we say the bond is a nonpolar covalent
bond
What is a polar covalent bond>
they share electrons
unequally, the electrons being held closer to one atom than to the other.
What is an element?
An element is a simple substance, made up of one type of atom. An element cannot be broken down
into anything simpler;
What is a compound?
A compound is a substance
made up of two or more different atoms bonded together.a compound can be broken down into elements
What are the 3 different phases of matter?
Gas, liquid solid
What are the charactersitics of gas?
A gas has weak attractions between the atoms or molecules and particles move in a
random and erratic manner. If placed in a container, a gas takes the shape of its
container and spreads to fill its volume.
What are the characteristics of a liquid>
A liquid has more attraction between its particles. It takes the shape of the container it
is in, but it does not vary in its volume.
What are the characteristics of a solid?
A solid does not take the shape of the container it is in and does not flow and its
particles have very little movement.
What is melting?
The process that takes a solid to a liquid is melting.
What is evaporation?
the process that turns a liquid to a gas
is evaporation.
The gas to liquid conversion is called
condensation.
A liquid turns into a solid by
Freezing
The direct change between the solid phase and the gaseous phase without an apparent liquid phase is called
Sublimation
What is vapor pressure
In a closed system, the evaporated
gas above a liquid exerts a pressure called vapor pressure, which is specific for each liquid
and at each temperature.
When would liquid boil at a lower temperature?
At high altitudes where the barometric pressure is lower, liquids boil at lower temperature.
A _____ mixture differs from a substance in that its composition may vary within a
sample;
heterogeneous
A ______ mixture is one in which the composition does not vary within the sample
homogeneous
In a solution, the substance that does the
dissolving is called the ____ and the substance being dissolved is the ____.
Solvent, solute
A _____ is a solution in which the solvent is alcohol.
Tincture
How can homogenous mixtures be seperated?
Homogeneous mixtures such as solutions can be separated by physical
means such as distillation or chromatography
An _____ for example, refers to a liquid dispersed in
another liquid in which it is not soluble
Emulsion
_____ is the ability of a solute to dissolve in a
particular solvent
Solubility
The addition of certain substances called _____ can
stabilize emulsions.
emulsifiers
How can heterogenous mixtures be seperated?
Heterogeneous mixtures can be separated by physical means such as
filtration.
Iron left exposed to the environment reacts with oxygen in the air. The result is a new compound, iron oxide. This type of change, in which a substance changes into a new and different substance, is a ______.
Chemical change.
______, a change in which the substance undergoing the change remains the same.
Physical change
The substances that react with each other are written on the left side of the equation are _______.
Reactants.
The substances that are the end products of the reaction are written on the right side of the equation are ______
Products
. The law of ______ of mass tells us that matter is
neither created nor destroyed
Conservation
_____, or _______, reactions involve two or more reactants that combine to create a
new product.
Synthesis, Combination
________ reactions involve an element reacting with a compound. During this reaction, an atom of the single element replaces an element in the compound.
Single replacement reaction
_______ reactions involve two ionic compounds. The positive ions, or metal, in
each compound switch positions.
Double displacement reactions
The _____ was created to identify the strength of an acid or a base (or alkaline)
depending on the concentration of hydrogen and hydroxide ions.
pH scale
pH below 7 as ____, a pH above 7 as ____, and a pH of 7 as _____
Acidic, basic and neutral
_______ involve one reactant that is broken down into two or more simpler
products. Often heat is used to drive this type of reaction.
Decomposition reactions
What does a reaction depend on?
- The two substances must come into contact.
- Enough energy has to be available. If the appropriate amount of energy, the activation energy, is available, then the reaction can proceed.
Why is a reaction rate increased because of an increase in high temperatures?
the reaction rate is increased by raising the temperature because an elevated temperature
causes particles to move around in a quicker and more erratic manner.
What are catalysts?
These are substances that increase the rate of a reaction by lowering the
activation energy needed. It is important to remember that catalysts only affect the rate of the
reaction and are not used up in it
A reaction that releases energy is called ____; its
products contain less energy than its reactants.
Exothermic
A reaction that absorbs energy is called
______; its products contain more energy than its reactants.
Endothermic
Most chemical reactions do not go to completion but instead reach _____
Equillibrium
At _____, the rate of the forward reaction is equal to the rate of the reverse reaction.
Equillibrium
Organic chemistry is the study of ______, which are compounds that contain carbon.
Organic compounds
What are organic compounds?
Compounds that contain carbon
Examples of organic compounds include______, such as methane or butane, alcohols, aldehydes, ketones, ethers, and esters
Hydrocarbons
What are organic compounds often represented with?
Structural formulas
_______ contain carbon, hydrogen, and oxygen, and the ratio of hydrogen to oxygen is typically 2:1.
Carbohydrates
______ are
the so-called simple sugars
Monosaccharides
______ are made from two monosaccharides and
include table sugar, or sucrose.
Disaccharides
______ are chains of monosaccharides and are
commonly known as starch and glycogen.
Polysaccharides
_____ is formed in plants, whereas _____ is
found in animals.
Starch, glycogen
A common test for the presence of starch is ______ , which turns blue-black in the presence of starch.
Lugol’s solution (iodine)
A common test for monosaccharides is ______ which, when heated with a simple sugar, turns brick red.
Benedicts solution
In ______ , the bonds between the carbons are single; in ______, the bonds tend to be double or triple
bonds.
Saturated fats, unsaturated fats
A common test for the presence of proteins is _____
Biurets solution
______ is a reaction in which small units, such as monosaccharides or amino acids, are
joined to form larger molecules. In this reaction, one molecule gives up a hydrogen atom and
the other an OH to form water and the two molecules bond.
Dehydration synthesis
_____ is the opposite; a large
molecule is broken down into smaller molecules by adding water (H2O) and putting the H and
OH back.
Hydrolysis
The ______ of an object is the distance and direction of the object from some starting
point (e.g. 15 meters at 45° north of east)
Displacement
When an object is in _____ its displacement is constantly changing.
Motion
How is motion described?
Motion is described by displacement, velocity (speed), and acceleration.
_____ is the distance traveled by an object per unit of time.
Speed
How is speed calculated?
Speed = Distance traveled/time
_____ is speed in a given direction; it therefore tells us two things about a moving object: its speed and its direction.
Velocity
The rate of change in velocity is called _____.
Acceleration
______ is sometimes used to refer to negative acceleration or a decrease in velocity.
Deceleration
How is acceleration calculated?
Acceletation = Final velocity - original velocity divided by time
Velocity and acceleration can both be described using _____ because they have both
magnitude and direction
Vectors
An object traveling at a specific velocity has a quantity called _____.
Momentum
How is momentum calculated?
Momentum = mass x velocity
One of the main laws of classical physics is the _______, which states that the total _________of an isolated system is always constant.
conservation of momentum, momentum
the law of _____, states that objects in motion tend to stay in motion and that objects at rest tend to
stay at rest.
Inertia
____ is the property of matter that resists any change in motion
Inertia
How is force calculated?
Force = mass x accleration
The ____ is the unit that represents a force that
gives a mass of 1 kilogram an acceleration of 1 meter per second.
Newton
Whenever a force is exerted on an
object along a surface or whenever an object has a velocity along the surface and the two
surfaces touch, there is a force called ____
Friction
_____ is the force of attraction between
all objects in the universe. The greater the mass of an object is, the greater its gravitational
force will be.
Gravity
Why is the earths gravitational force so strong?
The earth’s gravitational force is great because the earth has a large mass.
However, the _____ toward earth is the same for all objects, independent of their mass.
acceleration
What is density?
density, which is mass per unit volume
How is density calculated?
Density = mass/volume
The ability of a force that is applied perpendicularly to rotate an object around an axis, such as
using a wrench to turn a bolt, is measured by a quantity called ____… ____ is the perpendicular force times the lever arm.
Torque
The _____ is the distance from the axis of rotation
to the point where the force is exerted (e.g. the length of the wrench). The farther the force is
from the axis of rotation, the more torque is produced and the easier it is to rotate the object.
Lever arm
To keep a ball at the end of a string moving in a circle, you must continually exert a force pulling
the ball back toward the center of the circle. This force is called the _____ and, in
the case of the ball on a string, the string provides the force.
centripetal force,
______ is the ability to do work.
Energy
________ is energy associated with motion. Any moving body has this type energy
because it is able to do work by moving other bodies.
Kinetic energy
_______ is the energy stored in a body because of its position
Potential energy
______ is the rate at which work is done.
Power
An _________ is a slanted surface used to raise an object.
.
inclined plane
A ____ is a moving inclined plane.
Wedge
A ____ is an inclined plane wrapped around a cylinder.
Screw
A ____ is free to move around a fulcrum when force is applied.
Lever
A ____ is a chain or rope wrapped around a wheel.
Pulley
A ____ and ____ act as a lever that rotates in a circle
Wheel and axle
A _____ is a combination of two or more simple machines.
Compound machine
According to the _____ , the atoms in
matter are in a constant state of motion.
kinetic theory of matte
____ is the result of the impulses from the collision of molecules with the walls of the
container.
Pressure
_____ states that, when the temperature of a gas is kept constant, the volume
of a fixed amount of gas varies inversely with the pressure of the gas. If the volume
of the gas is decreased, both the number of particle collisions and the pressure of
the gas increase. If the volume of the gas is increased, the pressure of the gas
decreases.
Boyles law
_____ defines the relationship between the temperature and volume of a gas
when its pressure is kept constant. According to this law, the volume of a fixed
amount of gas varies directly with its temperature. If the temperature of a gas
increases, the volume increases.
Charles law
_______ is a measure of the
average kinetic energy of a single particles moving in a substance.
Temperature
_____ is a form of energy that causes the particles
of matter to move faster and farther apart.
Heat
_____ refers to
the physical change of a substance from one state to another.
Phase change
The______ is the heat energy needed per unit mass to change the
phase of a substance.
latent heat
In science, the most commonly used temperature scale is the ____ scale
Celsius
the ____ , or absolute temperature, scale.
Kelvin
The ____ is the temperature at which
ice melts or water freezes
Ice point
The _____ is the point at which water at standard pressure boils.
Steam point
The _____
(273.16 K) on the Kelvin scale is the temperature at which water exists simultaneously as a gas,
a liquid, and a solid.
Triple point
On the Kelvin scale, the lowest possible temperature is known as _____
Absolute zero
___ is a rhythmic disturbance that travels through matter or space, and ____ motion is a means of transferring
energy.
Wave
A ____ is a wave in which matter vibrates at right angles to the direction in which the wave
travels.
Transverse wave
A ______ is a wave in which matter vibrates
back and forth along the path that the wave travels.
longitudinal wave i
Sounds, for example, are transmitted by
______
longitudinal waves.
_____ is motion that repeats itself over and over again, such as the motion of a
pendulum.
Periodic motion
A ____ is motion that repeats itself at regular intervals and transfers energy, but not mass.
Periodic wave
The _____ of a wave tells us the number of cycles per second that a wave repeats itself (e.g.
10 cycles per second).
frequency (f )
Frequency is often measured in ____, which is equivalent to cycles per second.
hertz (Hz)
____ refers to the maximum distance a wave rises or falls (measured relative to the
wave’s undisturbed position) as the wave travels.
Amplitude
The ____ of a transverse wave is the maximum upward displacement and the ____ is the maximum downward displacement.
Crest; Trough
The ____ of a transverse wave is the distance
between two successive crests.
Wavelength
_____ is the frequency of the wave times the
wavelength
Wave speed
_____ between two systems occurs when the vibration of one system results in the vibration of the
other system at the same frequency.
Resonance
Light waves are made up of streams of tiny packets of energy called ____
Photons
Light waves are called _____ because the moving photons consist of electric and magnetic fields.
Electromagnetic
The complete spectrum of light, arranged in order of their wavelengths, is called the ____
Electromagnetic spectrum
_____ , only a small part of this spectrum, is the portion that is visible to the human eye.
Visible light
The ____ of a sound wave has to do with the frequency
Pitch
The ____ of a sound wave is
determined by its amplitude.
Loudness
The ______ occurs whenever there is relative motion between the source of waves and the observer
Doppler Effect
____ is the bending of light rays as they pass from one medium to another
because light moves at different speeds through different mediums.
Refraction
A prism is a piece of glass that
separates light into its component colors. This phenomenon is called _____
Dispersion
A lens that is thicker in the center than it is at the edges is a _____
Convex lens
The ____ is the point at which the
light rays meet.
Focal point
A _____is thicker at the edges than it is in the middle.
Concave lens
Electricity moving through a circuit is called a _____
Current
An ____ is the unit used to measure
electrical current
Ampere
