Biology test Flashcards
Cell theory
Prokaryotes vs eukaryotes
Eukaryotic cells are cells containing membrane-bound organelles and are the basis for both unicellular and multicellular organisms. In contrast, prokaryotic cells do not have any membrane-bound organelles and are always part of unicellular organisms
Cell structure
Oragnelles
A small structure in a cell that is surrounded by a membrane nuclei, which store genetic information; mitochondria, which produce chemical energy; and ribosomes, which assemble proteins.
Cell division
cells divide to create
new cells.
Purpose of CD
Reproduce
Repair Damage
Grow
CD reproduction
ALL cells use cell division to reproduce. When a parent cell divides it results in, 2 new organisms
Ex. Bacteria
A sexual reproduction
Offspring from one parent, genetically identical to one parent
Sexual reproduction
A cell from one parent joins with a cell from another parent.
Different as they contain half the
number of chromosomes found in
body cells. 2 gametes combine and get characteristics from both parents
Cell division for growth
It is better for an organism to have many small cells than one big cell.
When a cell gets too large:
Nutrients and water cannot move through it fast
enough.
Wastes cannot exit fast enough, chemical cells are used for growth
Diffusion
the net movement of molecules from an area of greater concentration to an area of lesser concentration
Concentration
The
amount of solute
(substance) in a
solution
Osmosis
when the water leaves and enters the cell important chemicals must be available to
cells in the right amount of water for the cell
to function properly.
Waste must also diffuse out of the cell not to
poison the cell.
Cell repair
Every day your body sheds skin cells that are replaced by new skin cells
Red blood cells are replaced every 120
days
Every cut and blister needs new cells to
fill in the gaps
If you break a bone, cells divide to heal
the break.
cancer
Cancer is a group of diseases in which cells grow and divide out of control It results from a change in the DNA that controls the cell cycle. Th is change prevents the cells from staying in interphase for the normal amount of time. One or more of the checkpoints (addressed in Section 2.5) fails, so the cell and all of its subsequent daughter cells continue to divide uncontrollably.
carcinogen
any environmental factor that causes cancer
mutation
a random change in the DNAchanges may either result in the death of the cell or allow the cell to survive and continue to grow and divide.
Hereditary
DNA passed from one generation to the next may contain information that leads to disease. Th ese cancers include some breast cancers and some colon cancers. A genetic link makes it more likely that you will develop a particular type of cancer, but it does not guarantee that you will get cancer.
pap test
a test that involves taking a sample of cervical cells to determine if they are growing abnormally
PSA test
used for men under the age of 50 as the incidence of prostate cancer is lower for that age group.
blood test
colon cancer regular skin checks by a doctor or dermatologist to look for changes in moles, new growths, and sores.
Treatment for cancer
surgery
chemo
Radiation
Biophotonics
Surgery
physically removing the cancerous tissueis sometimes the preferred way of treating cancer. If the tumour is easily accessible and fairly well defi ned, the doctors may recommend this option.
Chemo
Uses drugs-kills the cells Side eff ects may include hair loss, nausea, and fatigue, but the benefi ts of the treatment generally outweigh the negative effects. Shrinks tumour
Radiation
divides cells rapidly,Th e radiation is directed at the tumour either by using a focused beam or by implanting a radioactive source into the tumour. This minimizes side effects.
Biophotonics
the technology of using light energy to diagnose, monitor, and treat living cells and organisms
cells
Simplest/basic unit of life
tissue
A collection of similar cells that
perform a particular, but limited
function.
EPITHELIAL TISSUE
Description: thin sheets of packed cells covering surfaces
and lining internal organs
Function: protects structures, protects from dehydration
Examples: skin, lining of the digestive system
CONNECTIVE TISSUE
Description: various types of cells and fibres held together
by a liquid, a solid or gel known as a matrix
Function: support, insulation, join other tissues together
Examples: bones, tendons, blood, fat storage
muscle tissue
Description: Bundles of long cells called muscle fibres that
contain specialized proteins capable of shortening and
contraction. There are three major types: skeletal, smooth,
and cardiac.
Function: movement
Examples: heart, muscles that make bones move, muscles
that make up organs
Nerve tissue
Description: long, thin cells with branches at the ends
capable of conducting electrical impulses
Function: sensory, communication within the body,
coordination of body functions
Examples: the brain, respond to stimuli, transmit and store
information
Organ
Organ: A structure
composed of different types
of tissues working together to
perform a complex body
function.
Examples: stomach, small
and large intestines, liver,
pancreas, skin, heart
Organ system
All animals obtain oxygen and nutrients and eliminate wastes
They all sense and respond to their environment, grow and repair damage and
reproduce
Organ systems assist in these basic functions.
Each organ system consists of a group of organs that work together to carry out specific
duties in the body.
Animal organ system
Tissue comes together to form organs. Skin is and organ that protects the body. Organ can be made out of specific tissue
Plant organs
Roots: anchor the plants soil permits plant to row above soil without topping over, collect water and nutrients
Leaf:photosynthesis, carries water to complete process,sugar prodcued carried to vascular tissue
Stem: Transports water and nutrients thought out the plant, supports leaves and flowers
Flower: Reproductive structure,procude seeds,contains male organs.
DIgestive system
takes in
food, digests it, and excretes the waste.
Digestive tract
The digestive tract consists of the Mouth, Esophagus,
Stomach, Small Intestine, Large Intestine, Rectum
and Anus.
4 main
processes involved in
digestion:
Ingestion
Digestion
Absorption
Excretion
Ingestion
The mouth begins the process of breaking
down food.
Physical/Mechanical Digestion
Teeth and tongue
Chemical Digestion
Chemicals called enzymes break apart food
molecules
Chewing stimulates the salivary glands to secrete
saliva
Saliva: mixture of water, mucus and amylase
Amylase: enzyme that helps carry out chemical
digestion
Tongue
muscular
organ that helps move
food around until it forms
a ball called a bolus,
which the tongue pushes
back to the pharynx.
The tongue also contains
taste buds which helps
detect certain flavours.
Esophagus
Muscular tube (25 cm long)
that connects the mouth to the
stomach.
It is made of smooth muscle
that can relax and contract
without conscious thought.
Epiglottis
flap of cartilage that covers the trachea (windpipe) during swallowing and helps ensure
that food travels down
the esophagus to the stomach.
It preventschoking.
Stomach
muscles
contract and relax to
churn the food and mix it
with gastric juices to help
break down the food.
Small intestine
Fats, proteins and carbohydrates
are broken down. Finger-like projections called
VILLI absorb nutrients into the
blood.
Undigested material is pushed
into the large intestine.
Large intestine (colon)
The lining of the
intestine absorbs water
from the indigestible
food.
Colitis
The epithelial tissue lining of
the colon may become
inflamed and stop working
properly resulting in a
condition known as colitis.
Causes include viruses,
bacteria, narrowed blood
vessels, failure of the body’s
disease fighting mechanism.
Rectum
Feces are stored in
the rectum until they
are eliminated.
anus
The anus is made of a
ring of muscles that
pushes the feces
through
Pancreas
leaf shaped gland below the
stomach that secretes enzymes
to help with digestion.
The pancreas produces
INSULIN, an enzyme that
regulates the concentration of
glucose (a sugar) in the blood.
Diabetes is a disease in which
the pancreas produces too
much or too little insulin.
Liver
largest internal
organ.
The liver produces BILE, a
substance that breaks down
large fat molecules into smaller
ones. This process is called
EMULSIFICATION
Bile also causes feces to turn
brown and helps break down
alcohol.
Gallbladder
Small pouch on the
underside of the liver that
stores bile and sends it to
the small intestine.
Function of the circulatory system
Moves oxygen from the lungs to all the body cells
Moves carbon dioxide from the body cells to the lungs
Moves nutrients from the small intestine to the body cells
Moves waste materials from the body cells to the kidneys and skin
Regulates body temperature and transports disease-fighting white
blood cells to sites of viruses or bacteria
Components of blood
Red blood cells (RBCs) – Contains a protein called hemoglobin that
transports oxygen throughout the body and makes the cells appear
red. They make up 45% of the blood volume.
White blood cells – infection fighting cells that recognize and destroy
pathogens. They make up less than 1% of blood.
Platelets – Cells that help in blood clotting, making up less than 1 %
of blood.
Plasma – A liquid that carries blood cells along, making up 55% of
blood volume.
The heart
The heart pumps with a regular beat
(average heart rate = 70-80 beats per
minute)
Heart rate changes depending on:
physical activity, stress, temperature,
time of day, blood volume, whether you
have recently eaten and general health.
Parts of the heart
The atria
Receiving chambers
The ventricles
Pumping chambers
The valves
Prevent backflow
The septum
Divides the heart
Blood vessels
Arteries: carry blood away from the heart (under greater pressure
than other vessels)
Usually carry oxygenated blood
pulmonary artery is only exception
Veins: carry blood toward the heart. The wall of the veins are
thinner than the walls of the arteries and have valves that ensure
blood doesn’t flow backwards
Usually carry deoxygenated blood
pulmonary vein is only exception
Capillaries: connect arteries and veins. They are tiny blood vessels
with thin walls that are the site of gas exchange between blood and
cells
Path of blood
Deoxygenated blood enters the right
atrium from the superior and inferior
vena cava.
Blood from the right atrium is pumped
through the AV valve to the right
ventricle.
The right ventricle pumps blood to the
lungs through the pulmonary artery.
Oxygenated blood returns to the heart
from the pulmonary vein and enters the
left atrium.
Blood from the left atrium is pumped
through the AV valve to the left ventricle.
The left ventricle pumps blood to the
aorta from where it travels to the rest of
the body.
Disorders cardiac
Coronary arteries: blood vessels
that provide blood to the heart
muscle
These arteries can become partially
blocked with plaque.
Plaque: a deposit, made of fat,
cholesterol, calcium and other
substances that normally circulate
the blood.
Plaque buildup may be caused by
poor lifestyle choices such as a high
fat diet, lack of exercise and
smoking.
Coronary artery disease
Symptoms of coronary artery disease
Tiredness
Dizziness
Pain or burning in the chest or arms
This can be detected using a special x ray
called an angiogram.
Heart attack
arteries may become
completely blocked with plaque or a
blood clot.
When this happens and the heart
muscle cells stop receiving oxygen and
nutrients, the heart stops pumping and
the heart tissue starts to die.
Symptoms:chest pain
or pressure, shortness of breath, nausea,
anxiety, upper body pain, abdominal or
stomach pain, sweating, dizziness,
abnormal fatigue
Aneurysm
Bulging blood vessel
that can rupture and
cause a stroke,
internal bleeding, and
even death
Varicose Veins
Valve failure resulting in
backflow of blood
Causes enlargement of
superficial veins in
legs or rectum
(hemorrhoids)
Respiratory system
Take in oxygen and remove carbon dioxide
Works very closely with the circulatory system (which moves substances throughout the body)
Pathway of air
Air enters through the mouth and nose
Air then passes through the pharynx (throat)
It travels down the trachea (windpipe)
The trachea then separates into two branches called bronchi (singular: bronchus)
The bronchi branch again and again, ending in tiny air sacs called alveoli (singular: alveolus)
Structual features
the trachea and bronchi are lined with epithelial cells
Some produce mucus
Others have cilia (hair-like projections)
Cilia help move mucus and filter foreign material that might enter the system trachea is the tube that takes air into the lungs
The trachea is supported by rings of cartilage to keep it open and allow air to flow through it freely
gas exchange
Oxygen enters and carbon dioxide leaves the bloodstream in the lungs by diffusion. The alveoli have very thin walls
Each alveolus is surrounded by a network of capillaries
Oxygen and carbon dioxide must diffuse through two thin walls: the walls of the capillaries and the walls of the alveoli
Breathing
alternately drawing air into the lungs (inhalation) and then pushing air out of the lungs (exhalation)
This process involves:
Muscles between the ribs that move them, making the rib cage expand and contract
Diaphragm that sits below the lungs contracting and relaxing to draw the lungs down then up
Together, the muscles increase the volume of the lungs, and changes the pressure inside the lungs allowing air to flow in and out of the alveoli
Control of breating involuntary
Breathing is controlled by a part of the brain that senses CO2
If there is too much carbon dioxide detected, the breathing rate increases, as does the heart rate
This will help reduce carbon dioxide, and increase oxygen
Involuntary
TB
infectious disease (can be spread from person to person)
Caused by bacteria that grow in the lungs and may also spread to other parts of the body
Symptoms: fever, cough, weight loss, tiredness, chest pain
Diagnosed through a chest X ray and to confirm the diagnosis through examinations of stomach or lung secretions
The bacteria may remain dormant in the body for decades
Once diagnosed TB can be successfully treated with medicine and a few weeks of hospitalization
cancer
lol
SARS
Severe Acute Respiratory Syndrome (SARS) spread from a region of China to 37 countries around the world
Canada identified 438 cases; 44 of these patients died
Symptoms: flu-like, high fever, shortness of breath, dry cough, sore throat, headache, muscle pain, and exhaustion
Diagnosis is made based on chest X-ray, showing evidence of pneumonia, and positive lab results of cell samples
