Biology Keystone Module 2

Photosynthesis

Conversion of light energy from the sun (and carbon dioxide and water) into chemical energy (sugar, and oxygen as a byproduct).

producer

An organism that can make its own food.

consumer

An organism that obtains energy by feeding on other organisms

decomposer

An organism that breaks down wastes and dead organisms

cellular respiration

Process that releases energy (ATP, and water and carbon dioxide as a byproduct) by breaking down glucose and other food molecules in the presence of oxygen.

food chain

A series of events in which one organism eats another and obtains energy.

food web

A community of organisms where there are several interrelated food chains

trophic level

Each step in a food chain or food web

10% rule

Only 10% of the energy in one trophic level gets passed onto the next trophic level

food chain vs food web

A food chain outlines who eats whom. A food web is all of the food chains in an ecosystem.

energy pyramid

A diagram that shows the amount of energy that moves from one feeding level to another in a food web

biomass pyramid

Diagram representing the biomass in each trophic level of an ecosystem

pyramid of numbers

representation of the number of individual organisms in each trophic level of an ecosystem

biomagnification

accumulation of pollutants at successive levels of the food chain

Evolution

The gradual change in a species over time

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Differential Reproductive Success

better adapted individuals will more likely to survive, reproduce, and pass their traits on to the next generation

Artificial Selection

Selection by humans for breeding of useful traits from the natural variation among different organisms

Example of Artificial Selection

dog breeding, banana breeding

Example of Natural Selection (Lizard Activity)

Lizard population became larger, more spiky, and more drought-resistant over time due to environmental pressures

Charles Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Heritability

the ability of a trait to be passed down from one generation to the next

Adaptations

beneficial traits (physical traits, behavior, etc.) that improve an individual's ability to survive and reproduce

Survival of the Fittest

Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called natural selection

Speciation

Formation of new species

Temporal Isolation

form of reproductive isolation in which two populations reproduce at different times

Reproductive Isolation

condition in which a reproductive barrier keeps two species from interbreeding (fertilized egg is not viable)

Geographic Isolation

form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water

Ecological Isolation

species occur in the same area but occupy different habitats

Behavioral Isolation

isolation between populations due to differences in courtship or mating behavior

Types of Natural Selection

stabilizing selection, directional selection, disruptive selection

Stabilizing Selection

occurs when natural selection favors the average/intermediate/middle variation of a trait

Directional Selection

occurs when natural selection favors ONE of the extreme variations of a trait

Disruptive Selection

occurs when natural selection favors BOTH extreme variations of a trait (and/or selects against the intermediate variation)

Genetic Drift

A change in the gene pool of a population due to chance

Bottleneck Effect

Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.

Founder Effect

Genetic drift (change in allele frequencies) as a result of the migration of a small subgroup of a population

Eukaryote

A cell that contains a nucleus and membrane bound organelles (mitochondria, ER, Golgi, etc.)

Types of Eukaryotic Cells

Animal, Plant, Fungi, Protist

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

Types of Prokaryotic Cells

Bacteria, Archaea

DNA

deoxyribonucleic acid, the carrier of genetic information.

Sugar-Phosphate Backbone

The alternating chain of sugar and phosphate to which the DNA and RNA nitrogenous bases are attached

Nitrogenous Base

An organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA (ATCG)

Adenine

The base that pairs with Thymine in DNA

Thymine

The base that pairs with Adenine in DNA

Double-Helix

two strands of nucleotides wound about each other; structure of DNA

Twisted Ladder

double helix, shape of dna

Way to remember base-pair rules

Need to have their @ (AT) to put them in the group chat (GC)!

semi-conservative

Each half of an original DNA molecule serves as a template for a new strand, and the two new DNA molecules each have one old and one new strand.

Nucleotide

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

Practice: What is the complementary strand of ATC GGC CGA TAT?

TAG CCG GCT ATA

genetics

The scientific study of heredity

complete dominance

a relationship in which one allele is completely dominant over another

incomplete dominance

Situation in which one allele is not completely dominant over another allele - they BLEND

codominance

A condition in which both alleles for a gene are fully expressed

genotype

genetic makeup of an organism (allele combinations, e.g. Bb)

phenotype

An organism's physical appearance, or visible traits. (physically what trait does an organism have, e.g. black fur)

allele

Different forms of a gene

heterozygous

having two different alleles for a trait

homozygous

having two identical alleles for a trait

trait

A characteristic that an organism can pass on to its offspring through its genes. (e.g. fur color)

gamete

sex cell, sperm or egg

hybrid

Offspring of crosses between parents with different traits

Punnett Square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

Multiple alleles

three or more forms of a gene that code for a single trait (e.g. blood type ABO)

meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

diploid

2n - containing two complete sets of chromosomes, one from each parent.

haploid

n - having a single set of unpaired chromosomes

crossing-over

Exchange of genetic material between homologous chromosomes during Prophase I of meiosis LEADS TO GENETIC DIVERSITY

genetic flow

movement of genes from one population to another

Nucleic Acid

DNA is a type of macromolecule

Guanine

Nitrogenous base in DNA complementary to cytosine

Cytosine

One of the four nitrogenous bases in DNA

Base-Pair Rules

Adenine pairs with thymine, guanine pairs with cytosine

Double Helix

DNA structure resembling a twisted ladder

Watson and Crick

Scientists who established DNA's double helix structure

Nitrogenous Bases

Form the 'rungs' of the DNA ladder connected by hydrogen bonds (A, T, C, G)

DNA Replication

Process where DNA makes a copy of itself

Helicase

Enzyme unzipping DNA strands during replication

DNA Polymerase

Enzyme adding free nucleotides during DNA replication

Ligase

Connects lagging strands of DNA during replication

Transcription

Process of mRNA synthesis from DNA

Translation

Ribosome decoding mRNA to synthesize proteins

Ribosome

Site of protein synthesis in the cell

Codon

mRNA nucleotide triplet corresponding to an amino acid

Anticodon

tRNA nucleotide triplet attached to an amino acid

You have to have their ____ to put them in the ______! (Base-Pair Rules)

@ (AT); Group Chat (CG)

Stop Codon

codon that signals to ribosomes to stop translation

Start Codon

AUG (methionine)

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

Amino Acid

Building blocks of proteins, 20 types exist.

Protein

A three dimensional polymer made of monomers of amino acids.

Codon Chart

shows which mRNA codon codes for a specific amino acid in translation

What is the difference between DNA and RNA?

DNA: 1 type. Double stranded. T instead of U. Sugar deoxyribose

RNA: 3 types (mRNA, tRNA, rRNA. 1 stranded. U instead of T. Sugar ribose

What base does RNA have instead of T?

U

Why can't DNA leave the nucleus?

It's too big - double stranded

artificial selection

selective breeding of plants and animals BY HUMANS to promote the occurrence of desirable traits in offspring (e.g. ancient banana --> modern banana)

heritability

the ability of a trait to be passed down from one generation to the next