Biology Final June Flashcards
Theory of Evolution
Gradual development of new types of organisms from pre-existing types
Descent with modification
Process of evolution; all species descend from one original kind of life and change over time
Fitness
Relative ability for an organism to survive and produce fertile offspring
Adaptation
A heritable characteristic that increases an organisms ability to survive and reproduce.
Natural Selection
Organisms with variations most adapted to their environment to survive and leave more fertile offspring.
What are the five parts for evidence of evolution?
- Fossil record
- Biogeography
- Comparative anatomy
- Comparative embryology
- Molecular biology
Explain the law of superposition
If the rock layer at a certain location has not been disturbed…then the lowest layer is the oldest.
What is biogeography?
The study of locations where organisms lived and where there ancestors lived.
What is comparative anatomy?
Study of similarities and differences in the structure of different species.
What are homologous structures?
Structures that are found in different species yet are similar because they descended from a common ancestor.
What are analogous structures?
Similar functions that aren’t descended from a common ancestor.
What are vestigial structures?
Structures inherited by recent organisms that seem to have no significance but did in possible ancestors.
Comparative embryology
The study of similarity embryos
Molecular biology
Homologous structures are evidence of a common ancestor.
What is microevolution?
Evolutionary change that happens in a relatively short period of time within a population or species.
Population genetics
The study of evolution through a genetic standpoint.
What is a gene pool?
It is all the genes of all the members of a population.
Allele frequency
How often the allele occurs in a population
Harvey Weinberg Theorm
A population doesn’t change its allele frequency if it has NO mutation, NO immigration, NO natural selection, is very large, and if mates are chosen at RANDOM.
Mutations
Mutagens- mutations causing things; may be helpful or harmful.
Gene flow
The migration of fertile organisms or the transfer of gametes through a population—behavior can affect this.
What is genetic drift?
Change of allele frequency due to RANDOM cause
Speciation
Occurs when two parts of an interbreeding species are separated and stop interbreeding— occurs in two ways.
- geographic isolation
- reproductive isolation
Pure/true breeding
Homozygous
Dominant gene
Gene that prevents the other gene from showing
Represented by capital letters
Recessive gene
Does NOT show even thought it is present
Represented by lowercase letters
Must have 2 recessive alleles for a recessive trait to show
Genotype
alleles an individual inherits at a particular genetic locus
Phenotype
Characteristics of an organism that depend on how the organism genotype is expressed
PHYSICAL appearance resulting from gene makeup
Factor/allele
Different possibilities of a gene (for same trait)
2 alleles = 1 gene
Heterozygous
Two DIFFERENT alleles that are inherited
Homozygous
Two of the SAME alleles inherited. Genes come in pairs
23 sperm 23 egg
Trait
A characteristic that an organism can pass on to its offspring through its genes
Punnet square
Chart for determining the expected percentages of different genotypes in offspring of two parents
P1/F1/F2
P parental generation
F1 First generation of offspring
F2 Second generation of offspring
Traits can “skip” generations
Watson/Crick
Discovered that DNA has a double helix shape
Franklin
Used x rays to learn more about DNA’s structure
Parts of a nucleotide (DNA/RNA)
5 carbon sugar, phosphate group, and a nitrogen base
DNA bases
Adenine
Thymine
Guanine
Cytosine
RNA bases
Adenine
Uracil
Guanine
Cytosine
Purines
Double ring
Larger
Adenine and guanine
Pyrimidine
Single ring
Smaller
Thymine and cytosine
Double helix
two twisted strands of nucleotides
DNA polymerase
Helps with DNA replication
Hydrogen bond
Scientists concluded that hydrogen bonds between complementary bases hold together the two polynucleotide chains of DNA.
A bonds with T
C bonds with G
Deoxyribose
Five carbon sugar molecule that helps form the phosphate backbone of DNA molecules
Ribose
Sugar present in RNA
RNA polymerase
At the beginning of transcription, RNA polymerase binds to a region of a gene called the promoter. This signals the DNA to unwind so the enzyme can read the bases in on of the DNA strands.
Start codon
Codon that signals to ribosome to start translation
Stop codon
Codon that signals to ribosome to stop translation
mRNA
Messenger RNA
Carries info from DNA in nucleus out into the cytoplasm and to the ribosomes.
tRNA
Transfer RNA
Transfers the amino acids to the ribosomes for protein assembly
Each has an anticodon for the amino acid it carries
rRNA
Ribosomal RNA
Helps to build ribosomes
Transcription
DNA used to make mRNA
Happens in the nucleus
Is the first part of the central dogma of molecular biology
DNA—>RNA
Translation
mRNA needed to make a protein
Happens in a ribosome
Second part of the central dogma of molecular biology
RNA—>Protein
Promoter
Region of a gene where a RNA polymerase binds to initiate transcription of the gene.
When it binds, it signals the DNA to “unwind” so the enzyme can read the bases in the DNA strand
Codon
group of 3 nitrogen bases in nucleus acids that makes up a code word of the genetic code and stands for an amino acid
Ribosome
Organelles inside all cells where proteins are made
Location of translation
Genetic code
Universal code of three-base codons that encodes the genetic instructions for the amino acid sequence of proteins
Protein synthesis
Process in which cells make proteins that includes transcription of DNA and translation of mRNA
Polypeptide
Chain of amino acids that alone or with other such chains makes up a protein
Early Earth conditions including atmosphere
At first earth was Milton and lacked an atmosphere and oceans. Then the planet cooled and formed a solid crust. Volcanos released gasses and formed an atmosphere.
Early atmosphere had ammonia, methane, water vapor and carbon dioxide and only a little bit of oxygen.
Water from rain formed oceans
Miller-Urey experiment
An experiment where scientists Miller and Urey simulated if organic compounds could have arose in earths early atmosphere.
They thought lightning sparked chemical reactions so in the experiment they used an artificial spark.
First cells
Scientists speculate lipid membranes grew around organic molecules and RNA.
This formed the first cells
First cells are prokaryotes
First eukaryotes
First eukaryotes probably evolved 2 billion years ago.
By endosymbiosis they survived:
Large cell engulfed small cell and they helped each other survive.
This made eukaryotic cells powerful and efficient and they were able to adapt largely.
Then they would evolve into animals, plants, and fungi.
First organic compounds
No oxygen, when earth cooled compounds condensed in lakes—where complex compounds formed
Origin of heredity
RNA was the first Genetic Material
Taxonomy
Science of describing, naming, and classifying organisms.
Linnaeus
Created the way we classify in modern day.
His system grouped living things into a hierarchy based on their form and structure
The five kingdom system: Kingdom Phylum or division Class Order Family Genius Species
Scientific name
Use the system binomial nomenclature
It is the creatures genus name and species name
Directional selection
favors ONE extreme trait
Stabilizing selection
Favors average trait
Disruptive selection
Favors BOTH extreme traits
Genetic drift
A random change in allele frequencies that occurs in a small population.
Gene flow
Change in allele frequencies that occurs when individuals move into or out of a population.
What are the four types of modern plants?
Nonvascular plants
Vascular plants
Seed plants
Flowering plants
Characteristics of non vascular plants
Lack true leaves, seeds, or flowers
Lack vascular tissue
Have rhizoids to anchor to ground instead of roots
Characteristics of seeded vascular plants
Two types
Gymnosperm - cone
Naked seed
vs
Angiosperm- flowers
Retained, protected seed
Characteristics of flowering vascular plants
Angiosperms
Flowers
Retained, protected seed
Rhizoids
Hair-like structure in a non vascular plant that absorbs water and minerals and anchors the plant to a surface
Vascular tissue
Transport tissue
Xylem and phloem
Xylem
Hollow tubes that transport water
Phloem
Transports products of photosynthesis
Vascular tissue
Stamen
The male reproductive structure of a flower.
It consists of a stalk-like filament that ends in an anther
Anther
Contains pollen sacs, in which meiosis occurs and pollen grains form
Filament
Long thin structure that supports the anther
Pistil
Female reproductive structure of a flower that consists of a stigma, style, and ovary
Stigma
Raised and sticky to catch pollen
Style
Long slender stalk that connects the ovary and the stigma.
Ovary
One of two female reproductive organs that produces eggs
Petal
Attract pollinators to the flower.
Petals are often brightly colored and smell good so pollinators will notice them
Sepal
Protects the developing flower while it is still in the bud.
Usually green
Pollinators
An animal that moves pollen from a male anther to a female stigma on a flower.
Plant growth
Plants grow through a combination of cell growth and cell division. Cell growth increases the size while cell division increase the # of cells
Taproot
~Single, thick primary root
~Smaller secondary roots growing out from the sides
~anchors the plant to the ground
Fibrous root
~Smaller branching roots
~No large primary root
~Threadlike roots increase surface area for absorption of water and minerals
~Anchors badly
Root functions
- Absorbing water and minerals
- Anchoring and supporting plant
- Storing food
Evergreen vs. deciduous
Evergreen:
Keeps pines all year
Has reduced area for sunlight
Deciduous:
loses leaves
Loses energy from having to regrow
Invertebrates vs. Vertebrates
Invertebrates:
- no digestive system
- A simple central chamber with 1 opening
- a digestive tract
- in some animals, food is broken down and absorbed in the gut
vs.
Vertebrates:
- digestion occurs in the gut
- the gut is very longs and folded
- expel wastes while conserving water
Complete digestive system
Consisting of a digestive tract and two body openings (mouth and anus)
Incomplete digestive system
Consists of a digestive cavity and a single opening that serves both as a mouth and anus
Segmentation
The division of the body of an organism into a series of similar parts.
Open circulatory system
Pump hemolymph (blood cells with body fluid) into the space between the cells
Common to mollusks and arthropods
Elongation
New molecules are added to mRNA strand
Anticodon
Complimentary to the codon
Codon: AAG
Anticodon: UUC
Invertebrate gas exchange
Occurs... Directly across the body covering (skin) -ex worms Through book lungs -ex spiders Through spiracles
Vertebrate gas exchange
Occurs…
~Through gills of aquatic vertebrates
~Through lungs in terrestrial vertebrates
Termination
mRNA
Strand is done and detaches from DNA
Closed circulatory system
~Vertebrates and a few invert have a closed circulatory system.
~Closed circulatory systems have blood held at all times within vessels.
~blood is pumped by a heart through vessels and does not normally fill body cavities.
~vertebrates have a closed circulatory system with a multi chambered heart
List the hierarchy of taxa staring with the largest most inclusive grouping, to the smallest most exclusive grouping?
King Phillip came over from great Spain
Kingdom Phylum Class Order Family Genius Species
What direction do secondary roots grow?
They grow or branch out to the side
What are the three types of plant tissue?
Dermal tissue
Ground tissue
and
Vascular tissue
Secondary growth
Meristem around vascular tissue allows plant to grow in width
Primary growth
Meristem at the tips of the roots and stems allows plant to grow in length.
Which direction do primary roots grow?
Downward
List the three steps of transcription (In order)
- Initiation
- Elongation
- Termination
What is an example of a non vascular plant?
Moss
Also can say hornwort or liverwort
What is an example of a seedless vascular plant?
Ferns
Clubmosses
What is an example of a seeded vascular (nonflowering) plant?
Conifers
What is an example of a flowering vascular plant?
Any flower,
Roses
Tulips
Replication
Replication begins when an enzyme breaks the bonds between complementary bases in DNA
Builds new complementary strand to go with one parent strand
Species
The smallest, and most exclusive grouping
Consists of organisms that resemble each other and are capable of interbreeding to produce fertile offspring.
Second word of scientific name
Not capitalized
Should be italicized or underlined
Genus
Closely related species
First word of scientific name
Should always be capitalized
Should be italicized or underlined
What are the four nitrogen bases of DNA?
Adenine
Thymine
Guanine
Cytosine
What are chargaff’s rules?
A=T
G=C
What is the ribosomes role in translation?
To read mRNA codons and make sure the correct amino acid is attached.
What are the steps of building a polypeptide chain?
- mRNA and the ribosome come together at the start codon
- Amino acids are added one by one (as a mRNA codon is read correct tRNA carries in amino acid)
- Ribosome stops building when it reads a stop codon
What are some characteristics of seedless vascular plants?
True roots, leaves, and stem
No seeds
So spread around by spores
