Biology test 5

Different heritable features, such as flower color

Character variants, such as purple or white flower color

• Characters and character traits
• Mating easily controlled
• Stamens and carpel
• Cross pollination (fertilization between different plants) involves dusting one plant with the pollen of another

• Stamens
• Carpel

Plants that produce offspring of the same variety when they self-pollinate

Mating 2 contrasting, true-breeding varieties

P generation

The offspring of the true breeding parents

The product of when the F₁ generation self-pollinates or cross pollinates with another F₁ hybrid

Heritable factors

• Factors exist in versions (alleles)
• Alleles segregate/separate (law of segregation)
• Independent assortment
• Particulate inheritance

• Independent assortment of chromosomes
• Crossing over
• Random fertilization

• Easy to culture (small size; minimal nutrient requirements)
• Quick generation time
• Simple genetics
• Mutant form apparent
• Economic importance

Discreet expression or form, 1 among several, for a given character.

Individuals that are heterozygous for one character

Heterozygous for both traits

the two alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes

• •each pair of alleles segregates
• independently of each other pair of alleles during gamete formation

• When alleles are not completely dominant or recessive 
• More than one allele
• When a gene produces multiple phenotypes

occurs when phenotypes of the heterozygote and dominant homozygote are identical

the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties

two dominant alleles affect the phenotype in separate, distinguishable ways

an additive effect of two or more genes on a single phenotype

–Mendelian genes have specific loci (positions) on chromosomes

–Chromosomes undergo segregation and independent assortment

the most commonly occurring phenotype in nature

Cross the F₁ generation with itself

• Two traits on same chromosome
• sex-linkage: a trait that is linked on a sex chromosome

On Y chromosomes, code for male anatomical parts

• Female needs two copies of the alleles (heterozygous)
• Male needs one copy of the alleles (hemizygous)

offspring with same phenotypical traits as the parents

Offspring with phenotypical traits different from parents

Some of the DNA that is replicated is the old strand and some is new

Enzyme that prevents supercoiling by cutting DNA and then reconnecting it

Unwinds DNA

Protects DNA while in single stranded state

Each fragment on a lagging strand

Used to make proteins

Where the two DNA strands are separated, opening a replication bubble

An enzyme that starts an RNA chain from scratch and adds RNA nucleotides one at a time using the parental DNA template

Joins together Okazaki fragments

mRNA base triplet

Stretch of DNA that is transcribed

• Initiation
• Elongation
• Termination

Carried by tRNA. Base pairs with a complementary codon on mRNA

Y shaped region where new DNA strands are elongating

synthesizes a leading strand continuously, moving toward the replication fork

Short nucleotide strand where the 3' end serves as the starting point for a new DNA strand

The process by which DNA directs protein synthesis in transcription and translation

The synthesis of RNA under the direction of DNA

Synthesis of polypeptide using information in the mRNA

Ribosome

The initial RNA transcript from any gene prior to processing

• Concept that cells are governed by a cellular chain of command:
• DNA -> RNA -> protein

One of the two DNA strands that provides a template for ordering the sequence of complementary nucleotides in a RNA transcript

Pries the DNA strands apart and hooks together the RNA nucleotides

The DNA sequence where the RNA polymerase attaches

Sequence signaling the end of transcription

When enzymes in the eukaryotic nucleus modify pre-mRNA before the genetic messages are dispatched to the cytoplasm

The 5' end gets 5' cap and the 3' end gets a poly-A tail

• Facilitate the export of mRNA
• Protect mRNA from hydrolytic enzymes
• Help ribosomes attach to 5' end

Non-coding sequences in RNA

Regions that are eventually expressed and translated into amino acid sequences

Removes introns and joins exons

Consist of a variety of proteins and several small ribonucleoproteins (snRNPs) that recognize splice sites

• P site: holds the tRNA that carries the growing polypeptide chain
• A site: holds the tRNA that carries the next amino acid to be added to the chain
• E site: exit site where discharged tRNAs leave the ribosome

Replaces one nucleotide and its partner with another pair of nucleotides

Have no effect on the amino acid produced by a codon because of redundancy in the genetic code

Still code for an amino acid, but not the correct amino acide

Change an amino acid codon into a stop codon nearly always leading to a nonfunctional protein

Frameshift mutation

Physical or chemical agents that can cause mutations

1859

Scale on which organisms were arranged by Aristotle when they were thought to be static

Organisms are molded by catastrophe

Mechanisms of change are constant over time, such as weathering/erosion, sedimentation, subsidence/uplift

Similarity coming from common ancestry

Anatomical resemblances that represent variations on a structural theme present in a common ancestor

Remnants of features that served important functions in the organism's ancestors

Geographic distribution of species

Species that are not found anywhere else in the world

Evolution of similar or analogous features in distantly related groups

When a species does not take the carrying capacity of its habitat into consideration so therefore produces too many offspring which then die rapidly, creating a sharp incline and decline in population

R max

• Direct (bones, tissue)
• Indirect (footprints, dung, teeth marks)
• Micro and macro (unicellular organisms)

• Variation in a population
• Phenotype/physical differences associated with differences in reproductive success (fitness)
• Populations always grow beyond the environment's capacity to support them
• Competition ensues
• Differential reproduction and survival of so-called "favored" variation