biol113 exam 2

SUPERGROUP EXCAVATA

"excavated" feeding groove; phagotrophy; related to Earth's earliest euks

SUPERGROUP PLANTS & RELATIVES

phylum rhodophyta and chlorophyta

SUPERGROUP ALVEOLATA

membrane sac called alveoli

SUPERGROUP STRAMENOPILA

straw like hairs on surface of flagella

SUPERGROUP RHIZARIA

thin hair like extensions of cytoplasm called filose pseudopodia

SUPERGROUP AMOEBOZOA

amoebae with pseudopodia

SUPERGROUP OPISTHOKONTA

single posterior flagellum on swimming cells; includes animal & fungi kingdoms and related protists (i.e. choanoflagellates

haptophytes

plastids originated via secondary endosymbiosis; unicellular marine photosynthesizers (i.e. coccolithophorids)

periphyton

attached by mucilage to underwater surfaces; produce multicellular bodies; seaweeds or microalgae

means of nutrition in protists

phagotrophy, osmotrophy, photoauthotrophy, mixotrophy

defense strategies in protists

bioluminescence, toxins, slimy mucilage or tough cell walls, trichocysts (i.e. projectiles)

zygotic life cycle

haploid cells develop into gametes; + and - gametes fuse to produce thick-walled diploid zygotes (cysts)

sporic life cycle/alteration of generations

many multicellular green and brown algae; haploid gametophytes produce gametes and diploid sporophytes produce spores by meiosis

gametic life cycle/diatom reproduction and growth

All cells except the gametes are diploid, and gametes are produced by meiosis. Like a laboratory plate, when diatoms asexual divide they are split into a larger and a smaller half. As time goes on, the smaller half can get smaller and smaller and eventually trigger sexual reproduction. In sexual reproduction, the smaller half becomes covered in mucilage and each cell produces haploid gametes. The gametes fuse and produce a large diploid zygote. This 2n diatom undergoes mitosis and splits into two diploid cells.

ciliate sexual reproduction

occurs via conjugation; macronucleus and micronucleus; macronucleus are the source of genetic information. Two cells fuse and micronuclei undergo meiosis, exchange, fusion, and mitosis

Bryophytes

Nonvascular plants that do not contain specialized cells and have restricted growth; sporic life cycle

key components of vascular plants

Stem, roots, leaves

Phloem, xylem contains tracheids and allows plants to conduct water and compounds through plant body and provides structural support through lignin

Secondary metabolites

Synthesis of molecules that are not essential for cell structure and growth;Terpenes and terpenoids (commercial use stuff), phenolics, alkaloids (hormones/drugs)

Pollination syndrome

Some flowers specialized for particular pollinators

Birds: reds Bees: blues, purples, yellows, whites

Monocot

One codyledon, flowers parts of 3

Eudicot

Two codyledons, flower parts of 4/5

supergroup excavata

Feeding groove "excavated" into the cells of many representatives; phagocytosis

Supergroup of Plants & Relatives

Includes land plants and several algal phyla

Phylum Rhodophyta

Red algae; apparars red bc of red photosyntethic pigments; lacks flagella; unusually complex life cycles; most are multicellular marine macroalgae

Phylim Chlorophyta

Green algae; Kingdom Plantae evolved from these ancestors; occurs in freshwater , the ocean, and on land and they contain the same type of \n Plastids and photosynthetic pigments as true plants

Haptophytes

Primarily unicellular marine photosynthesizers;

Phylum Chytrid

Simplest fungi; produce flagellate cells (for spite of gamete dispersal); some are parasites

Phylum Zygomycota

Mycelium mostly aseptate hyphae; named after zygospore produced sexually

Phylum Glomeromycota

AM fungi

Phylum Ascomycota

Hyphae subdivided into cells by septa with simple pores; sprain his called asci; sexual spores are called ascospores; asci produced on fruiting bodies called ascocarps; chestnut blight, Dutch elm disease, Apple scab, truffles and morels are examples of decomposes and parasites

Phylum Basidiomycota

Hyphae has septa with complex pores; rusts and smuts are examples of fruiting bodies

Fungal endomycorrihizae

Fungal hyphae penetrate the spaces between root cell walls and plasma membrane and grow along the outer surface of the plasma membrane; AM

Fungal Endophytes

Live within the leaf and stem tissues of various types of plants; obtain organic food molecules from plants and in exchange contribute toxins that deter predators

Lichens

Partnership of heterotrophic fungi and phototroph; phototroph provides O2 and organic materials and fungi provides CO2, H2O, and minerals

Fungal Ectomycorrhizea

Coat root surface and grow between cells of roots; less invasive

Similarities b/w animals & fungi

Heterotrophic, absorptive nutrition, store surplus food in form of glucogen

Conidia

Asexual spores at the types of hyphae

Ascocarps

In Ascomycota, asci is produced on these fruiting bodies.

Mitosis

Production of all other cell types (somatic cells=body-belonging)

Meiosis

Leads to the production of reproductive cells (sperms and eggs)= gametes

Cytokinesis

the division of the cytoplasm into two distinct cells

Differences between Mitosis and Meiosis

Mitosis: production of somatic cells, genetic material is copied & then divided equally between 2 cells. Meiosis: production of gametes, daughter cells are genetically different from each other and have half the amount hereditary material as parent cell, cross over occurs

Basic steps in cellular replication

1. Copying the DNA (deoxyribonucleic acid)
2. Separating the copies
3. Dividing the cytoplasm to create 2 complete cells

Similarities between Mitosis and Meiosis

Cytokinesis

DNA

encodes the cells hereditary information or genetic material

Gene

A region of DNA in a chromosome that codes for a particular protein or RNA

M phase

Cells are in the process of separating their chromosomes their chromosomes. (meiosis/mitosis)

Interphase

Between phases. Cells is either growing and preparing to divide or fulfilling its specialized function in a multicellular individual.

Synthesis (S) phase

Part of interphase. Process of copying the genetic material

G1 phase

Gap between the end of phase and the start of S phase. \n Cell deciding to replicate

G2 phase

Second gap between the end of S phase and the start of M phase. Cell grows to prepare for M phase

M phase 5 subphases

1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase

Prophase

(Before phase) Chromosomes condense into compact structures -Formation of spindle apparatus

Prometaphase

(Before middle phase) Nuclear envelope disintegrates -Cytoplasmic microtubules attach to chromosomes attach to chromosomes at specialized structures called kinetochores.

Kinetochores Each sister chromatid has its own kinetochore, assembled at the centromere.

Centromere Attachment site for chromatids

Metaphase

(middle phase) Chromosomes are lined up on an imaginary plane between the two spindle poles called the metaphase plate.

Anaphase

(against phase) \n -Each replicated chromosome is pulled apart, creating two independent daughter chromosomes \n -When complete, two complete sets of chromosomes are fully separated, each set being identical to that of the parent cell before chromosome replication.

Telophase

(end phase) \n -the nuclear envelop re-forms around each set of chromosome, and the chromosome begin to de-condense

Variation and G1

Variation is due to the length of G1 phase. \n -In rapidly dividing cells, there isn't really a G1 phase at all. It's sort of eliminated and the cell just keeps replicating chromosomes and dividing over and over again. \n -Nondividing cells, remain only in G1 phase. When the cell just remains in the G1 phase and doesn't move, it's also called G0 state.

G0 state

Nondividing cells get permanently stuck in G1 phase

M phase-promoting factor

\-induces M phase in all eukaryotes. \n -made up of two different proteins \n ->protein kinase and a cyclin

Cyclin

Just a type of protein \n a regulatory protein \n there are different types of cyclin

Kinase

phosphorylates other enzymes

Concentrations of these different molecules

\-kinase stays the same throughout no matter what the cell is doing \n -but the concentration of cyclin varies. goes up and down as the cell is moving through the cell cycle and it peaks during M phase.

What causes MPF formation?

when MPF cyclin concentration gets high enough it causes the formation of MPF, it binds with kinase.

specific kinase cyclin bonds to

cyclin-dependent kinase (cdk)

cyclin-dependent kinase (Cdk)

in order to do its job of phosphorylating with other enzymes it has to be bound to a cyclin. once they are bounded together, then this kinase component will catalyze the phosphorylation of other proteins and this will initiate the beginning of M phase.

How is MPF turned off?

\-During anaphase, an enzyme complex begins degrading the cyclin. (It actually destroys it) This deactivates the MPF. The kinase is left alone and its concentration stays the same throughout the cell cycle.

Enzyme that turns off MPF

\-made during mitosis \n -functions as a negative feedback for MPF

Negative feedback

\-when process is slowed down or shut down by its own product -one of the products of mitosis is the formation of its enzymes, it degrades the cyclin, which stops mitosis from happening anymore.

what are checkpoints

prevent the division of cells that are damaged or that have other problems

what happens if the defect is in the proteins that regulate each checkpoint

the defect cell will keep diving... eventually forming a tumor

what happens if the cell doesnt pass the checkpoint

the cell just dies or repair itself

G1 checkpoint, passes if

\-cell size is adequate -nutrients are sufficient -social signals are present -DNA is undamaged

social signals

signals from other cells that are telling it to divide

G2 checkpoint, passes if

chromosomes have replicated successfully -activated MPF is present -DNA is undamaged

M-phase checkpoints

1. chromosomes have attached to spindle apparatus
2. Chromosomes have properly segregated and MPF is absent.

cancer

\-arise from cels which cell-cycle checkpoints have failed. -cells divide uncontrollably -invade nearby tissues and spread all over the body -they use nutrients and space needed by healthy cells & disrupt function of normal tissues.

Two main problems that'll cause cancer

1. Proteins required for cell growth (MPF) remain activated when they should not be activated. Cyclin all the time, instead of its normal up and down cycle.
2. Tumor suppressor genes (P53) fail to shut down the cell cycle when its supposed to stop

P53 gene

supposed to activate genes to stop cell cycle when cell fails checkpoint until damage is repaired or destroyed

a treatment of cancer (anticancer drug)

taxol comes from bark of specific yew tree

taxol

kills replicating cells by inhibiting depolymerization of microtubules during M phase. (stops the microtubules from being destroyed and this stops the cell from dividing)

microtubules being targets of taxol

\-they depolymerize during anaphase.

\-they prevent chromosomes from separating if the micro is destroyed

\-so cell dies and can't be destroyed.

Genetic variation

1. crossing over-produces new combinations of alleles within a chromosome
2. Independent assortment-creates varied combinations in gametes 3.Meiosis produces genetic diversity among offspring

Crossing over

\-occurs in late prophase 1 \n -paternal and maternal homologs exchange genetic material \n -at least one chiasma forms

chiasma

points of contact

independent assortment

\-occurs in metaphase plate I. when homologous chromosomes line up at the metaphase plate during meiosis, they line up independently from each other. \n -mixture of maternal and paternal

Trisonomy 21- Down Syndrome

Most common cause of trisomy 21 is error in homologous chromosomes separation during meiosis 1. \n result of nondisjunction

Nondisjunction

\-mistakes in microtubule attachment \n -mistakes in separation of chromosome due to inflexible cohesion protein

trisomy

2n+1= 3 copies of one type of chromosome

monosomy

n-1= only one copy of one of the chromosome

self-fertilization

when two gamete produced by the same individual fuse to form a diploid offspring.

outcrossing

when gametes from diff individuals combine to form offspring.

Law of segragation

occurs in anaphase 1. \n sister chromatids are separated. so alleles for the same trait separated into separate gametes.

reciprocal cross

a cross in which the phenotypes of the male and female are reversed compared with a prior cross

test cross

the crossing of an individual of dominant unknown genotype with a homozygous recessive individual to determine the unknown genotype

_________ IS THE FOUNDATION OF EVOLUTION

GENETICS

Linkage

tendency of alleles from different genes to be inherited together because they are located close to each other on the same chromosome. \n ex: eye and body color located on the x chromosome in fruit fly and are usually inherited together. red eyed flies almost always have brown bodies. PRINCIPLE OF INDEPENDENT ASSORTMENT DOES NOT APPLY.

Are linked genes always inherited together?

No, sometimes crossing over breaks it up and creates new combination of alleles. -most likely to break up alleles that are located far apart on a chromosome.

recombinant

an individual with a new combination of alleles.

Genetic map

\-indicates relative distance between genes on a chromosome. \n -frequency of crossing over btwn two genes on the same chromosome can be used to create a genetic map.