science semester 2 final Flashcards
a trait that helps an organism survive, opposable thumb
adaptation
a blood vessel that carries blood away from the heart
artery
the upper chambers of the heart
atria
reproduction with 1 parent, 1 set of DNA, makes exact copies but fast
asexual reproduction
a cell that protects the DNA and helps the organism survive harsh conditions
endospore
change in a species over time
evolution
when there are no living members of a species remaining
extinct
a trace of a living thing, like a cast, mold, footprint, most common in sedimentary rock
fossil
a stable internal environment
homeostasis
holds bone to bone
ligament
the soft inside of bone where blood cells are made or fat is stored
marrow
the control center of a cell
nucleus
reproduction with 2 parents and 2 sets of DNA, produces variety
sexual reproduction
one type of living thing, can breed and viable offspring under natural circumstances
species
holds bone to bone
ligament
prevents blood from going backward
valve
differences in an organism’s features (characteristics)
variation
back bone
vertebrae
a cell that fights off infection
white blood cell
How do scientists determine the actual age of fossils?
radioactive dating
How do fossils form?
organisms are buried in sediment before they can decompose
What is the role of genes in evolution?
Genes are passed from parents to offspring. Inherited traits are controlled by genes. Helpful genes are passed on more through natural selection because they help the parent survive.
If two organisms look very similar during their early stages of development, this is evidence that the organisms could have what?
a common ancestor
What is it called when an organism creates more offspring than can possible survive?
over production
What is mass extinction? What do scientists think caused mass extinctions?
many species go extinct at the same time - climate change
What do fungi have in common with animals?
heterotrophs
What characteristic do all algae share?
autotrophs
Compare viruses and parasites.
Both have host cells.
Why is a virus’s protein so important?
helps it attach to host
Why are some bacteria called decomposers?
break dead things down and return nutrients to soil and air
Why are viruses considered nonliving?
They don’t show all the traits of a living thing.
What directly provides energy for a virus?
host cell
What is the best treatment for most viral infections?
resting, fluids, and well-balanced meals
What stimulates a person’s body to produce chemicals that destroy viruses or bacteria?
vaccines
How does a vaccine work?
it injects dead or weakened forms of germs that activates your body’s immune system so it is prepared
WHy don’t people get sick after a vaccination?
made from dead or weakened germs that activate immune system
A hidden virus becomes part of a host cell’s what?
genetic material
Which organ system makes blood cells?
skeletal system
What is the function of the skeleton?
support, protection, stores fat, stores minerals, makes blood, leverage for movement
Most of a newborn’s skeleton is made of what?
cartilage
Describe the three types of muscle, and say which tires quickly
- cardiac - in heart
- skeletal - attached to bones - tires quickly
- smooth - in hollow organs
Explain why pairs of skeletal muscles work together.
bicep and tricep - when one contracts, the other relaxes - move bones in opposite directions
How does skin protect the body from disease?
It is a barrier that keeps germs from getting in.
When an individual washes their skin, what can they prevent?
infections and disease
What helps protect your skin from the sun?
melanin, hat, sunscreen
What are 4 levels of human body organization?
cell, tissue, organ, organ system
Are bones alive or dead? Explain.
alive - made of cells and produce blood cells, grow and develop, have a metabolism
What is homeostasis, and why is it so important to the body?
stable internal environment keeps body in check and allows chemical reactions
Name the 4 types of joints and their type of motion.
- hinge - back and forth
- ball and socket - greatest range of motion, can be a circle
- pivot - rotation
- gliding - 2 flat surfaces
If your pulse goes up, what happens to your heart beat?
speeds up
needed substances are carried to the body by what?
blood
What component of blood is 90% water?
plasma
What is the function of the cardiovascular system?
pumps blood to carry oxygen and nutrients throughout body and fights infection
If a person’s blood contains only anti - B clumping proteins, what is their blood type?
A
How many loops does the circulatory system contain?
2 loops
Explain why people with AB blood can accept blood of any type but can only donate to AB.
have no anti A or anti B
will react to both anti A and anti B
