Sdsu Bio 100 Exam 2 (Kacsinta)

Virus reproduction

Virus must infect a living cell as a parasite that directs that cells internal machinery to make more viruses

3 parts of a virus

nucleic acid, capsid, recognition spike

bacreriophage

A virus that infects bacteria

lytic cycle

a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses

lysogenic cycle

a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA

When did Charles Darwin publish the Origin of Species?

November 24, 1859

Evolution

witnessed as adaptation, the accumulation of favorable traits in a population over time

artificial selection

The selective breeding of domesticated plants and animals

What is Darwin's term for evolution?

"descent with modification"

fossil record

the ordered sequence of fossils found in layers of rock, with older fossils buried further down and new fossils near the surface

radiometric dating

based on the breakdown of the radioactive isotopes found in all living matter

Macroevolution

encompasses such major changed as the origin of new species, mass extinction and the diversification of new forms of life

speciation

evolutionary formation of new species, increases the diversity of life on earth

Two mechanisms of speciation

non branching, and branching evolution

Systematics

the classification of organisms to shed light on their evolutionary relationships

phylogenetic trees

a hypothesis about the evolutionary history of related species

clade

a group that consists of an ancestral species and all its descendents

Cladistics

the analysis of clades

invasive species

a non native species that occupies a foreign habitat and spreads quickly

biological control

the intentional release of a natural enemy that attacks the invader

intergraded pest management

method that utilizes several strategies. (ex. pest resistant crops varieties, careful monitoring)

how can evolution be understood?

by following the changes to DNA and genes over generations

how is evolution defined?

only in terms of changes in population over time

smallest unit that can evolve

population

Mutations

random changes in DNA, can create different versions of genes

gene pool

all of the forms of all the genes in a population at any one time

Microevolution

generation to generation change in the gene pool, evolution occurring on its smallest scale

2 mechanisms to the changes to the genetic make of a population:

mutations, sexual recombinations (shuffles existing genes)

Darwinain fitness

the contribution that an individual makes to the gene pool of the next generation in comparison to the contributions from other individuals.

Mechanisms of Evolution:

genetic drift; bottleneck effect and founder effect, gene flow, sexual selection

Genetic drift

change in gene pool due to chance

bottleneck effect

a change in the gene pool due to such a reduction in population size

founder effect

change due to the establishment of a small population

gene flow

individuals migrate into or emigrate out of a population

how are species recognized?

by their ability to naturally and successfully breed

species

a population that is capable of interbreeding to produce healthy offspring that can themselves reproduce (cant be applied to bacteria or extinct species)

behavioral isolation

Form of reproductive isolation in which populations have differences in types of behavior that prevent them from interbreeding

habitat isolation

populations live in different habitats and do not meet, or rarely meets

gametic incompatibility

The gametes (sperm and egg) of different species usually cannot fertilize each other.

mating time differences

many species are able to reproduce only at specific times

mechanical incompatibility

members of different species often cannot mate because their anatomies are incompatible

hybrid weakness

offspring of two species may be unfit, or they may be sterile

Speciation

Formation of new species, occurs when one ancestral species evolves into one or more new species

Key events in speciation

separation of a single population into two or more populations that are isolated from each other

graduated model

a model of evolution in which there is a slow and gradual change of a species over long periods of time

punctuated equilibrium

describes such periods of stasis (no change) interrupted by occasional bursts of speciation

allopatric speciation

a physical barrier arises that physically isolates population from each other

sympatric speciation

the emergence of a new species right in the midst of its parent population without geographic isolation

natural selection

the process by which organisms with certain traits are more likely to survive and reproduce than other organisms

Endomemberane system

a series of internal membranes and membrane enclosed organelles that are largely interconnected ( includes the endoplasmic reticulum, nuclear envelope, golgi apparatus, vesicles, and plasma membrane

Endosymbiosis

occurs when one species lives inside another host species

Where did mitochondria and chloroplasts come from?

evolved from small, free living prokaryotes that were engulfed

Four major groups of plants

bryophytes, seedless vascular plants, gymnosperms and angiosperms

humans belong to the order...

humans are mammals who belong to the order of primates. early primates lived in trees, humans belong to a group of primates called apes

Hominins

the human branch of the evolutionary tree of life

when did humans split off?

humans are primates that split off from other lineages 6-7 million years ago

prokaryotes

two domains of single celled life bacteria and archaea, first life to evolve on earth and only kind of life to exist for over 1 billion years

binary fission

"splitting in half"

may prokaryotes reproduce by...

Binary fission

Biofilms

communities of organisms attached to a surface such as rocks or living tissues

each individual bacterium has...

one chromosome, a closed loop of DNA containing genes

Transformation

the uptake of naked DNA from the surrounding environment into a bacterial cell

Conjugation

the transfer of DNA between two bacterial cells through a physical bridge

Sex pilus (plural: pili)

a hollow cellular extension

Donor cell in conjugation uses...

a sex pilus to form a physical connection to a recipient cell. Dc transfers a copy of its chromosome through a mating bridge

Transduction

the transfer of bacterial genes by a bacteriophage (also called phage) a virus that infects bacteria

Plasmid

small circular DNA molecule ( a "mini chromosome" typically containing just a few genes) that resides in the cytoplasm of a bacterium and can replicate independently of the bacterial chromosome

AIDS (acquired immunodeficiency syndrome) is caused by...

HIV (human immunodeficiency virus). HIV is 1/60 the size of the blood cell it attacks

Retrovirus

a viruses with RNA genome that is converted to dna prior to viral reproduction (ex. HIV)

what cell does HiC destroy?

helper t cells, a key component of the human immune system

emerging virus

one that has rapidly come to the attention of scientist

Pathogen

an agent that causes disease, many are living organisms, such as bacteria, fungi, protists, but some aren't alive

prion

infectious protein, misshapen versions of normal brain proteins

viroids

small circular single stranded RNA molecules that are capable of infecting and causing disease in plants

ciruclatory system

a collection of organs and tissues that act as an internal transport network

cariovascular system

consists of the heart and blood vessels

pulmonary circuit

shuttles blood from the heart to the lungs

heart

receives blood via veins then pumps it out via arteries

arteries

vessels that carry blood away from the heart

Arterioles

small vessels that receive blood from the arteries

Capillaries

tiny blood vessels that run through nearly every tissue of the body. very thin walls that allow material to be exchanged between the blood and the body's cells

Venules

small tubes blood enters as it exits capillaries

immune system

the body's system of protection against infectious diseases

inflammatory response

nonspecific defense against infection, characterized by redness, heat, swelling, and pain

First line of defense

hairs and cilia, mucous membranes, stomach acid, skin, secretions

Lymphocytes

white blood cells, comes in 2 varities- B cells and T cells

Antigen

amolecule that elicits an immune response

B cells secrete...

antibodies- proteins that circulate in the blood that are specific for that same antigen

clonal selection

allows the immune system to maintain a vast army of cells, but produces reinforcements only when they are needed

Helper T cells

can recognize antigens and then stimulate the production of several types of immune cells

allergies

sensitivities to allergens

autoimmune disease

occurs when the immune system improperly turns against the body's own molecules

immunodeficiency diseases

result when one or more components of the immune system are missing or defective

Vaccination/Immunization

involves purposefully exposing the immune system to an antigen, which stimulates the production of memory cells

endocrine system

consists of several endocrine glands and other tissues that make and secrete hormones

hormones

chemical signals that are produced by endocrine tissues and then transported by the circulatory system to other parts of the body, where they communicate regulatory messages

Endocrine specialist

thyroid and pituitary glands

where are hormones stored within an endocrine cell?

stored in membrane (enclose vesicles)

water soluble hormones

bind to matching protein receptors on the surface of the cell

fat soluble hormones

can diffuse through the fatty cell membrane