Semester 2 Biology Flashcards
Heterozygous
When the alleles from each parent are different
Dominant
Allele that covers up the recessive allele
Recessive
Allele that gets covered up by the dominant. (Lower case).
Gamete
Egg and sperm
Zygote
First cell formed after fertilization
Karyotype
Chromosomes removed from a dividing cell. Placed in a chart according to size with their homologous partner. Helps determine gender and genetic disorders.
Genotype
A list of alleles for possible offspring
Phenotype
List of appearances for possible offspring. Physical traits.
Probability
The likelihood that a particular event will occur
Law/principle of independent assortment
Genes for different traits can segregate independently during the formation of genes.
Principle of segregation
Each gamete carries only one allele for each gene.
Mendel
Founded genetics
Gene
A piece of DNA
Trait
A specific characteristic for an individual
Carrier
Someone who has the gene for a trait, but doesn’t express/ show it
P1 generation
The first generation
F1 generation
Second generation
F2 generation
Third generation
Test cross
A individual of unknown genotype is crossed with a homozygous recessive individual
Mono hybrid cross
A cross between individuals that uses one trait
Co dominance
Both alleles are dominant and fight for expression
Incomplete dominance
Neither allele is completely dominant. (Blending).
Sex determination
A punnet square using x and y can be used to find probability that kid will be a boy or girl. There is a 50 50 chance.
Dihybrid cross
Any cross involving two traits at a time. Use 16 squares.
Chromosome
Genetic info bundled into packages of dna
Chromatid
One of the two identical parts of a duplicated chromosome.
Centromere
Where the two sister chromatids meet and are held together.
Genetic linkage
Tendency for alleles on one chromosome to be inherited to the other due to meiosis.
Homozygous
Both alleles are the same letter and case
Pedigrees
A family tree that can be used to determine sex-linked traits of offspring
Locus
The location of a gene on a chromosome
Differences between DNA and ran
DNA is a long polymer with a phosphate and deoxyribose backbone. It has four different nitrogenous bases, adenine thymine cytosine and guanine. RNA has a ribose and phosphate backbone. It’s four bases are adenine guanine cytosine uracil. RNA1 chain DNA 2 chains
Ribose
Backbone of RNA
Deoxyribose
Backbone of DNA
Purines
2 carbon rings (a,g)
Pyrimadines
1 carbon ring (t,c)
Nucleotides
Building block of DNA. Includes 1 phosphate, 1 deoxyribose, and 1 nitrogenous base.
Mutation
Heritable changes in genetic information. Good bad lethal or neutral. Frame shift: add or delete a nucleotide. Point: one nucleotide is switched.
Hydrogen bonds
Weak. Between a and t are two hydrogen bonds. Between g and c are three hydrogen bonds
Covalent bonds
Strong. Holds backbone together
DNA replication
During the s of interphase, the DNA doubles using enzymes
Helicase
Unzips hydrogen bonds. Breaks into two strands
DNA polymerase
Deals out the correct nucleotides to the old strands of DNA, creating two new identical strands
Replication fork
When the DNA separates it takes in the appearance of a fork
Repair enzymes
Proofread and fix mutations
Promoter
Marks the beginning of a gene.
Termination signal
Where transcription stops. Marks the end of a gene.
Transcription
The process of copying instructions from DNA to mRNA
Translation
The process of decoding the mRNA into a protein
Codon
Any three mRNA nucleotide sequences that code for an amino acid
Anticodon
A three nucleotide sequence on tRNA. The exact opposite of mRNA codon
Start codon
AUG. Codes for the AA met. All polypeptides start with met
Stop codon
UAA, UAG, UGA. No AA match these sequences
MRNA
Messenger RNA. copies and transports instructions from the DNA to the ribosome. AKA: transcript
tRNA
Transfer RNA. Decodes the instructions and builds the protein. Transfers amino acids
rRNA
Ribosomal RNA. Location of protein synthesis. 2 put together = 1 ribosome. Is the most abundant organelle
Steps of protein synthesis. Steps of transcription
RNA polymerase binds to the promoter and relaxes DNA. RNA polymerase moves to the first nucleotide of the template chain. A complimentary mRNA chain is built using A,G,C,U. RNA polymerase teaches the termination signal and pops off to be recycled. MRNA transcript gets processed. DNA returns to normal.
Steps of translation
The process of decoding the mRNA into a protein. Ribosome attaches to the mRNA strand. tRNA with its anticodon and appropriate AA, attaches to the codon of the mRNA chain within the ribosome. Only two tRNA’s can fit into the ribosome at a time. Two AA’s bind together with peptide bonds. tRNA pops off to be recycled. This continues until the whole mRNA sequence is read.
Amino acid
Th building blocks of a protein
Polypeptide chain
Two or more amino acids in a chain
Protein
Composed of one or more long chains of amino acids
Jim Watson
American biologist. Co discoverer of the double helix
Francis crick
British biologist. Co discoverer of the double helix
Maurice Wilkins
English physicist whose research contributed to the scientific understanding of DNA
Rosalind Franklin
English chemist who made contributions to the understanding to the molecular structure of DNA and RNA
Gel electrophoresis
A laboratory method used to separate mixtures of DNA and RNA, or proteins according to size. Molecules are separated or pushed by an electrical field through a gel that contains small pores(auger). Pipette and tip
DNA fingerprinting
The sample that’s lines match up with the suspects, is the match.
Classification system
Kingdom, phylum, class, order, family, genus, species
Taxonomy
Grouping organisms according to characteristics and evolutionary history
Phylogeny
Evolutionary history of an organism
Binomial nomenclature
Includes genus and species. ( Genus species, italicized)
Linnaeus
Developed the 4 level classification system of binomial nomenclature.
5 kingdoms and characteristics
Monera:single celled, have a cell wall, have no chloroplasts or any other organelle, no nucleus.
Protista: single celled. Usually no cell wall. They have a nucleus and may have chloroplasts.
Fungi: multicellular with a cell wall. Have a nucleus, no chloroplasts.
Plantae: multicellular, nucleus, chloroplasts, photosynthesis.
Animalia: multicellular, digestion, nucleus, no chloroplasts
3 domains
Bacteria:unicellular prokaryotes. No cell membrane. Asexual reproduction
Eukarya: unicellular and multicellular eukaryotes. Cell membrane.
Archaebacteria: unicellular prokaryotes. No cell membrane. Asexual reproduction.
Darwin
Developed the theory of evolution
Natural selection
The environment chooses the organisms with variations that are most likely to survive.
Fitness
Are well adapted to their environment so they survive and reproduce.
Fossil
Traces of dead organic matter
Extinction
When an entire species dies off
Biogeography
Study of geographical distribution of fossils and of living organisms.
Pangea
An original huge continent before continental drift occurred.
Homologous structure
Similar structures in species that originated from a common ancestor
Vestigial structure
Structures that seem to have no function now, but may have helped past generations
Embryonic homology
Embryos of related organisms are very similar
Conserved genes
Genes that have remained unchanged throughout evolution
DNA similarities
Similarities in DNA between related organisms
First organisms to appear on earth
Single celled organisms called archaea
Population
Group of organisms of the same species living in the same area
Variation
There is natural variation in inherited traits due to random mutations
Artificial selection
Humans speed up evolution by selective breeding.
Gene pool
All of the alleles in all of the individuals that make up a population
Bottleneck effect
Population went so low that gene pool was small
Biodiversity
The huge variety of animals on this planet
Bilateral symmetry
If cut in half , both sides would be the same. Anything with a head
Radial symmetry
All parts radiate out from s central point and are the same.
No symmetry
No patterns can be found that repeat
Open circulatory system
Where the blood and interstitial fluid are allowed to mix within an organism
Closed circulatory system
Good always flows inside vessels. What humans have
Vertebrate
Has a backbone
Invertebrate
Doesn’t have a vertebrate
Cephalization
Having a head with sense organs and nerves
Exoskeleton
Skeleton on the outside
Endoskeleton
Skeleton on the inside
Fluid-filled body cavity
Earthworms and roundworms have it
Freshwater habitat
Puddles ponds streams rivers lakes inland marshes
Marine habitat
Live in saltwater
Brackish habitat
Area where fresh and saltwater meet. Like an estuary where a river meets the ocean.
Terrestrial habitat
Animals live on land
Anterior
Head
Posterior
Tail
Dorsal
Back
Ventral
Stomach
Autotrophs
Make their own energy
Heterotrophic
Need to consume plants or other animals for energy
Mechanisms for breathing
Gills, skin, lungs, trachae
Incomplete metamorphosis
Egg, nymph, adult
Complete metamorphosis
Egg, larvae, pupa, adult
Chrysalis
Pupa of a butterfly
Cocoon
Pupa of a moth
Coelom
True body cavity, completely lined with mesoderm
Ectoderm
Sense organs, nerves, skin
Mesoderm
Muscles, circulatory, reproductive, and excretory organs
Endoderm
Linings of the digestive tract and much of the respitory system
Blastopore
A hollow call of cells in early embryonic development. As it developed it folds and becomes a tube that creates the digestive tract. The tube only has one opening called the blastopore.
Protosome
Blastopore becomes the mouth
Deuterostomes
Blastopore becomes the anus
Segmentation
Most parts are repeated in each segments
Cerebral ganglia
Nerve bundles in the head
How worms move
Posterior setae grip the ground. Circular muscles contract. Anterior end advances. Anterior setae grip the ground. Longitudinal muscles contract. Pulling the posterior end forward.
Worm digestion
Pharynx obtains food. Esophagus. Crop stores. Gizzard grinds dirt. Intestines absorb nutrients. Anus excretes waste.
Respiration and excretion of worm
Breathes thru skin. Nephridia. Eliminates liquid waste and balances h20
Clitellum
Thick area on worm secretes mucus to stick worms together for reproduction
Jointed appendages
What all Arthropoda have.
What type of circulatory system do Arthropoda have
Open
Antennae
Can be used for tasting smelling or tactile functions
What three sections of the body do class insects have
Head thorax abdomen
What two sections of the body to arachnids and crustaceans have
Cephalothorax abdomen
Compound eye
Have many lenses
Cheliped
Pinches on phylum Crustacea
Characteristics of all chordates
Notochord, dorsal hollow nerve chord, pharynial slits, postanul tail
Vertebrate characteristics
Vertebral column (spine). Cranium(brain). Endoskeleton. Cartilage and hard bone. Tetrapods. Hinged lower jaw.
Characteristics of fish
Operculum( moves water over gills for gas exchange). Swim bladder( can be filled with gasses to make the fish buoyant). Lateral line (sensory organ used to detect when water is moving differently. Scales (make the fish hydrodynamic and sleek).
Characteristics of amphibians
Pulmonary circulation (takes blood to the lungs). Tadpoles (the middle stage that swims in water in metamorphosis). Webbed feet ( to swim better). Heart (have a three chambered heart). Metamorphosis.
Characteristics of reptiles
Amniotic egg (hard outer shell with amniotic fluid on inside so baby doesn’t dry out). Completely terrestrial( lungs for respiration). Chelonia(turtles). Crocadilia ( crocs and alligators). Squamata ( snakes and lizards). Three chambered heart
Characteristics of birds
Feathers made of keratin. Down feathers: prevent heat loss. Contour feathers: shape, color, and insulation. Flight feathers: flight. Light skeleton. Can fly. When birds inhale only 25% goes to lungs, other goes to air sacs. Beals adapted to food they eat.
Characteristics of animals
Endothermic. Mammary glands to feed young. Give birth to live young. Have hair and fur.
Tools for dissection
Forceps(tweezers), scalpel(knife), probe(poker thingy), scissors
