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113 terms

Science Semester 2 Vocab

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alleles
different forms of a gene
alveolus
tiny air sac at the end of a bronchiole in the lungs that provides surface area for gas exchange to occur
antibiotics
compounds that block the growth and reproduction of bacteria
arteries
large blood vessels that carry blood from the heart to the tissues of the body
ATP
large protein that uses H+ ions to bind ADP and a phosphate group together to produce ATP
atrium
large muscular upper chamber of the heart that receives and holds blood that is about to enter the ventricle
cartilage
strong connective tissue that supports the body and is softer and more flexible than bone
cellular respiration
process that releases energy by breaking down food molecules in the presence of oxygen; made of glycolysis, the Krebs cycle, and the electron transport chain
detritivores
organism that feeds on plant and animal remains and other dead matter
diffusion
process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated
down syndrome
if two copies of an autosomal chromosome fail to separate during meiosis, an individual may be born with three copies of a chromosome
eukaryotes
organism whose cells contain nuclei
genes
sequence of DNA that codes for protein and thus determines a trait
genetic engineering
process of making changes in the DNA code of living organisms
genotype
genetic make up of an organism
hemoglobin
iron- containing protein in red blood cells that transport oxygen from the lungs to the tissues of the body
heterozygous
term used to refer to an organism that has two different alleles for the same trait
homeostasis
process by which organisms maintain a relatively stable internal environment
homozygous
term used to refer to an organism that has two identical alleles for a particular trait
karyotype
set of photographs for chromosomes grouped in order in pairs
ligaments
strip of tough connective tissue in a joint that holds bones together
lymph nodes
places where blood cells hang out to fight infection; filters that trap bacteria
lymphatic system
returns excess fluid to the circulation; fights infection and disease
mesentery
keeps the small intestine in place; anchors all the blood vessels
nervous system
consists of central (brain and spinal cord) and peripheral (all other nerves); coordinates body's response to changes in its internal and external environment
nondisjunction
error in meiosis in which homologous chromosomes fail to separate
pancreas
glands that produce hormones that regulate blood sugar; enzymes that break down carbohydrates, proteins, lipids, and nucleic acids; and sodium bicarbonate, a base that neutralizes stomach acid
parasites
organisms that live in or on another organism and harms that organism by feeding on it
pathogens
disease causing agent, such as bacteria or fungus
pedigree
chart that shows the relationships within a family
phenotype
physical characteristics of an organism
photosynthesis
process by which plants and some other organisms use light energy to power chemical reactions that convert water and carbon dioxide into oxygen and high- energy carbohydrates such as sugars and starches
platelets
cell fragment released by bone marrow
prokaryotes
single- celled microorganisms without a nucleus
sex- linked genes
genes located on the X or Y chromosome
sterilization
process of destroying bacteria using great heat or chemical action
tendons
tough connective tissues that join skeletal muscle to bone
Turner's syndrome
only a single X chromosome; sterile female- sex organs don't develop; widened neck; more than 2 nipples
veins
blood vessels that return blood to the heart
hypothalamus
regulates body temperature, emotion, hunger, and thirst
thalamus
sensory and motor integration
pituitary gland
produces hormones
myocardium
thick layer of heart muscle tissue that contracts and pumps the blood
systolic pressure
force felt in the arteries when the ventricles contract
diastolic pressure
force felt in the arteries when the ventricles are relaxed
atherosclerosis
when fatty deposits called plaque build up on the walls of arteries
heart attack
when one of the coronary arteries becomes blocked and part of the heart muscle begins to die from lack of oxygen
fibrinogen
protein responsible for the ability of blood to clot
lymph fluid
(blood plasma) filters the fluid to remove bacteria and other microorganisms
thymus gland
helps mature T cells (white blood cells) and produce hormones
lymphatic system
supply fluid to circulatory system; fight infection; help in fat absorption
kidneys
two fist sized organs located near lower back; removes extra water and waste; controls blood pressure; red blood cell regulation; helps maintain chemical balance in body; helps maintain acid base pH; Vitamin D activator
nephron
tiny complex structures that filter blood plasma to remove wastes and to control the water and salt concentration of the blood plasma
medulla
drainage
tissue
groups of similar cells that perform a single function
organ
group of tissues that work together to perform a specific function
organ system
a group of organs that perform closely related functions
integumentary system
serves as a barrier against infection and injury; helps regulate body temperature; protection from the sun
respiratory system
provides oxygen needed for cellular respiration and removes excess carbon dioxide from the body
digestive system
converts food into simpler molecules that can be used by the cells of the body; absorbs food
excretory system
eliminates waste products of metabolism from body; maintains homeostasis
skeletal system
supports the body; protects internal organs; allows movement; stores mineral reserves; site for blood cell formation
muscular system
works with skeletal system to produce voluntary movement; helps to circulate blood and movement through the digestive system
circulatory system
brings oxygen, nutrients, and hormones to cells; fights infection; regulates body temperature
endocrine system
controls growth, development, metabolism, and reproduction
reproductive system
produces reproductive cells; in females, nurtures and protects developing embryo
feedback inhibition
process by which the product of a system shuts down the system or limits its operation
epithelial tissue
cover the surface of the body and line internal organs; lining along the chambers of the heart prevents leakage of blood; glands are made of epithelial tissue
respiration
breathing
sinuses
blocks dust particles from entering the nose; trap bacteria; brings in molecules that are connected to our nervous system (ole factory)
nasopharynx
intersection where food, smells, and breathing pass through
epiglottis
a trap door; when we eat, the door is open; when we swallow, the door closes
larynx
(voice box) as air tries to go up and down, it passes through the larynx
trachea
cartilage rings
keratin
tough fibrous protein; basic structure of hair and nails
melanin
dark brown pigment
dermis
inner layer of the skin
melanocytes
cells that produce melanin; most people have roughly the same number of melanocytes in the skin
epidermis
outer layer of the skin
hair follicels
produces hair
white blood cells
leucocytes or phagocytes; no hemoglobin; have nuclei; engulf and/ or destroy invading particles and bacteria; part of the imune system; some escape through capillaries
red blood cells
also called erythrocytes; carries oxygen (attached to hemoglobin) to body cells; carries CO2 away from body cells; made in the bone marrow; no nucelus
plasma
55% of the total blood; mixture of 90% water, 8% proteins, .9% minerals; small amounts of amino acids, simple sugars, and metabolic wastes; interstitial fluid or Lymph
blood
humans contain 4 to 6 liters
organism
a collection of organs working together for the common good of the organism
platelets
cell fragments that start clotting; release enzymes that build up a fibrous clot to stop bleeding
synapse
location at which a neuron can transfer an impulse to another cell; the narrow space between neurons
neurotransmitters
chemicals used by a neuron to transmit an impulse across a synapse to another cell
threshold
the minimum level of a stimulus that is required to activate a neuron
action potential
reversal of charges due to the flow of positive ions into a neuron
sensory neurons
carry impulses from the sense organs to the spinal cord and brain
myelin sheath
an insulating membrane; leaves nodes where the axon membrane is exposed
bone
made up of calcium and phosphorous; living tissue
periosteum
tough layer of connective tissue surrounding bone
haversian canals
network of tubes running through bone
spongy bone
bone with a latticework structure
compact bone
thick layer of dense beneath the periosteum
somatic nervous system
conscious control; muscle- skeletal movement
autonomic nervous system
unconscious controls; helps maintain homeostasis of body
motor neuron
carries impulses to a muscle or gland to cause action
interneurons
transfers impulses from one neuron to another
sensory neuron
found near body surfaces to receive stimulus
salavary glands
chemical digestion; digestive enzymes; produce saliva
liver
produces bile; breaks down fats
gall bladder
stores bile
large intestine
removes water
espophagus
"food tube" between the pharynx and stomach
stomach
chemically breaks down food; mechanically breaks down food; hydrochloric acid and pepsin
small intestine
absorbs broken down nutrients
pancreas
produces something that changes the acids
punctuated equilibrium
a pattern in which species experience long, stable periods interrupted by brief periods of rapid evolutionary change
gene pool
combined genetic information of all members of a particular population
convergent evolution
process by which unrelated organisms independently evolve similarities when adapting to similar environments