92 terms

Biology

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What is a Punnett square?
a way to keep track of the possible genotypes in a cross
Probability
the likelihood that a particular event will occur
Dominant characteristics
occurs most often because only one allele is needed for the characteristic to appear
Recessive characteristics
masked by a dominant allele. requires two to appear
homozygous alleles
two of the same alleles. AA & aa
heterozygous alleles
two different alleles. Aa
recessive alleles
form of a trait that can be masked. aa
hybrids
heterozygous organisms
incomplete dominance
no dominant allele. heterozygous phenotype is blended
codominance
both are dominant and both are expressed
sex-linked
located only on the X chromosome
blood types
A and B are dominant. O is recessive
PKU
inability to breakdown phenylalanine (recessive)
sickle cell anemia
affects red blood cells and ability to transport oxygen (codominant)
colorblindness
not being able to see certain colors (sex-linked)
Huntington's disease
affects the nervous system (dominant)
Human Genome project
determine the sequence of the nucleotides that make up human DNA
mRNA
carries genetic info from DNA to direct protein synthesis in the cytoplasm
tRNA
transports amino acids to the ribosome
rRNA
associates with protein to form the ribosome
Transcription
synthesis of mRNA from DNA (nucleus)
translation
code is read and translated to make a protein (cytoplasm)
replication
parent strands of DNA serve as a template and produce DNA molecules of one parent strand and one new strand
what enzyme controls DNA replication
DNA helicase
where does DNA replication occur
in the nucleus because that is where the DNA is located
nucleotide
basic structure that makes up DNA
what makes up a nucleotide
five-carbon sugar, a phosphate group, and a nitrogenous base
how are DNA and RNA different
RNA has ribose, has uracil instead of thymine, and it's single-stranded
what is the start codon
AUG
what are the stop codons
UAA, UGA, UAG
what do stop codons do
signals the endof protein synthesis
how many nitrogenous bases make up a codon
3
genes contain instructions for assembling which important macromolecule?
protein
test cross
breeding an organism that has an unknown genotype with an organism with a known genotype to determine the unknown one
restriction enzymes
proteins that recognize and bind to specific DNA sequences and cleave the DNA within the sequence
autosomes
pairs of chromosomes that aren't sex chromosomes (44)
sex chromosomes
female - XX
male - XY
karyotype
pairs of homologous chromosomes are arranged to determine if there is something wrong
transgenic organism
genetically engineered by inserting a gene from another organism
how has the theory of continental drift influenced evolution
if the earth changed, life had to too
what is a geologic time scale
a model that expressed major geological and biological events in earth's history
relative dating
method used to determind age of rocks by comparing them with those in other layers
radiometric dating
uses the decay of radiactive isotopes to determine the age of rock
half-life
amount of time it takes for half of the original isotope to decay
natural selection
process by which individuals that are better suited to their environment survive and reproduce most successfully
speciation
a population must diverge then be reproductively isolated
fitness
ability to survive and reproduce
homologous structures
anatomically similar structures inherited from a common ancestor
analagous structures
used for the same purpose and can be superficially similar but aren't inherited from a common ancestor
vestigial structures
reduced forms of functional structures in other organisms
geographic isolation
separation of populations as a result of geographic change or migration to geographically isolated places
adaptive radiation
one species gives rise to many species in response to the creation of a new habitat or another ecological opportunity
convergent evolution
unrelated species evolve similar traits even though they live in different parts of the world
gradualism
evolution occurs in small, gradual steps over time
puntuated equilibrium
rapid spurts of genetic change cause species to diverge quickly; these periods punctuate much longer periods when the species exhibit little change
primary role of fungi in the environment
break down dead material
what do fungi eat
dead organisms, a host, or a plant
how and where do fungi digest their food
produce enzymes that breakdown organic material then they absorb nutrients through their thin cell wall
2 characteristics of bryophytes
small, nonvascular. no true leaves
what are vascular tissues used for
specialized transport tissues used to move substances faster and over large areas
what are vascular tissues made of
xylem and phloem
gymnosperm
naked seed
angiosperm
flowering plants
what has an endoskeleton and a backbone
a vertebrate
arthropod
jointed legs that extend from body; has exoskeleton
mammals
live birth; feed with milk; endothermic; covered in hair
birds
feathers; lay eggs; warm-blooded
amphibians
ectothermic; eggs; smooth moist skin; live on land and in water
reptiles
ectothermic; eggs with protective shells; dry skin covered with scales
amniotic egg
covered with a protective shell and has several internal membranes with fluids contained between the membranes
marsupial
pouched mammal who's offspring have a short period of development in the uterus then have a long period of development in the pouch
placental
specialized organ that provides food and oxygen to developing young and removes waste in a mammal
monotreme
mammal that only reproduces by eggs
notochord
flexible, rodlike structure extending the length of the chordate body, enabling the body to bend and make side-to-side movements
homeostasis
regulation if an organims internal environment to maintain conditions needed for life
how do you maintain a healthy immune system
eat healthy, exercise, get vaccinated
primary purpose of sweat glands
secrete sweat that evaporates and draws heat away from the body
what are the three kinds of protists
animal-like, plant-like, and fungus-like
where can protists be found
damp or aquatic environments
what is cilia
short, hair-like projections used for movement and to obtain food
how do ameoba move
psuedopods
taxonomy
system of grouping based on characteristics
what are the 7 taxanomic levels from biggest to smallest
kingdom, phylum, class, order, family, genus, species
what is binomial nomenclature and what are the two parts
scientific name with two parts. genus then species
what are the 6 kingdoms
archaebacteria, eubacteria, protista, fungus, plants, and animalia
which of the 6 kingdoms are prokaryotes
eubacteria and archaebacteria
which of the 6 kingdoms are eukaryotes
protists, fungus, plants, and animals
conjugation
form of reproduction used by some prokaryotes in which the prokaryotic cells attach to each other and exchange genetic material
binary fission
asexual form of reproduction used by some prokaryotes in which a cell divides into 2 genetically identical cells
prion
protein that causes infection or disease
cell wall of mushrooms are made of what
chitin
what type of genetic material is present in a virus
DNA or RNA