bio exam review

• adhesion = water attracts to xylem walls

• cohesion = water attracts water

cohesion-adhesion

• xylem closer to stem centre

• phloem closer to outside

• vascular cambium separates xylem and phloem

herbaceous stem

• DICOT ONLY

• grow thicker over time

• makes new xylem and phloem each year

• sapwood (young xylem) conducts minerals and water

• old xylem = hardens into heartwood

• bark protects woody stems

• tree rings determine climate and tree age

woody stem

structure performing specific functions in the cell

organelles

• contains and protects genetic material from cell

• double membraned for more selective permeability

nucleus

• receives, modifies, packages and transport proteins made by ER

golgi apparatus

• makes spindle fibres

• helps separate and reorganize genetic material during mitosis

centrioles

• filled with enzymes and bounded by membrane

• enables digestion

• considered recycling centre of cell

lysosomes

• found on ER surface

• protein synthesis

• floats in cytoplasm

ribosomes

• transports materials throughout cells

vesicles

• store water and starch

• surrounded by tonoplast (membrane)

vacuoles

• provides movement to certain cells

• made of fine protein fibres

• cilia = shorter, flagella = longer

cilia + flagella

• gives cell energy from food molecules like glucose

  • energy turns into ATP

• site of cellular respiration

• co2 from energy gets eliminated for cell

mitochondria

• supportive network of fine protein fibres

  • anchors organelles in place

  • microtubules + microfilaments

cytoskeleton

• ONLY IN PLANTS! and certain protists

• contain chlorophyll

• makes carbs/sugars via photosynthesis

chloroplasts

• interior structure/lining of a tube

  • ex: intestines have lumen

lumen

• large

• animal + plant cells

• membrane bound organelles

• reproduce by mitosis/meiosis

• double-stranded chromosomes in nucleus

eukaryotic cells

• smaller

• bacteria cells

• circular chromosomes

• no membrane bound organelles

• reproduce via binary fission

prokaryotic cells

smooth:

• no ribosomes

• makes lipids (fats)

rough:

• protein synthesis

• has ribosomes

endoplasmic reticulum

• process of traits passing from parents to offspring

• chromosomes carry genes

• important for cell reproduction/division

heredity

specific location of gene on chromosome

locus

order of genetic info coding specific trait

gene

• made of nucleotides (subunits)

  • pentose sugars (5 carbon sugars)

  • nitrogen base

  • phosphate base (PO4)

structure of nucleic acids

• deoxyribonucleic acid

  • found in nucleus

  • main components of genes

  • sugars in nucleotides = deoxyribose sugars

dna

• found in nucleus

• instructs protein making

• nucleotides sugars = ribose sugars

rna

purines

• large

• double ringed

• adenine + guanine

pyrimidines

• small

• single ring

• thymine + cytosine

two types of dna nitrogen bases

adenine + thymine, guanine + cytosine

how do the dna nitrogen bases pair?

uracil + adenine, guanine + cytosine

rna nitrogen base pairings

rna = single helix

dna = double helix

• order of bases = acid individuality

dna and rna helix

• new offspring made from single parent

• made from single parent cell division (no sex cells)

• clones, invariable generations

asexual reproduction

• offspring from fusion of 2 sex cells

• offspring not identical to parents

• variable generations

sexual reproduction

study of heredity and variation in genes

genetics

diploid = 2 sets of chromosomes (2n)

haploid = half the number of chromosomes

polypoid = 3+ sets

diploid, haploid, polypoid

variation of life in one area, divides into genetic, species and ecosystem

biodiversity

• sum of all different genes in species

• small differences = individual uniqueness

  • allows better adaption to change

genetic diversity

more vulnerable to disease/illness, climate changes or prey/predator changes

what happens with low genetic diversity?

• variety of species in one area

• more variety = healthier ecosystems

• more species = more complexity

species diversity

• variety of habitats + organisms and their connections

• diverse ecosystems range in size/complexity

ecosystem diversity

when organisms live in/on other organisms

walking ecosystems

grouping similar organisms together for specific reasons

classification in biodiversity

archea, bacteria, animalia, protists, plantae, fungi

6 kingdoms

• must be similar in structure

• must breed under natural conditions

• must be fertile

species requirements

• consumes living/dead organisms for energy

• unable to make their own food

heterotroph

makes their own food using the sun

autotroph

main classification groups in hierarchy format going more and more specific

taxon

kingdom, phylum, class, order, family, genus, species

taxon groups in order

archaea = only archaebacteria

eukarya = animals, plants, protists, fungi

bacteria = only eubacteria

domains

• one of 2 identical chromosome strands

• attached to each other by centromere

chromatid

• found in eukaryotic cell nucleus

• carries genes

chromosome

• thread like structures

• made of dna and proteins

• found in nucleus of eukaryotic cells

• forms chromosomes

chromatin

g1: cell growth and preparing for duplication

s (synthesis): genetic info gets duplicated

g2: final prep for cell division

name and describe stages of interphase (mitosis)

• “regular” cell division

• occurs in somatic cells

• when tissues must replace themselves

• parent cells divide and make 2 clone daughter cells

what’s mitosis

• cells grows too big - surface area doesnt match volume

  • too much volume = nucleus loses activity control and transport becomes too difficult

• allows organism growth

• maintains healthy cells

why does mitosis occur

PMAT - prophase, metaphase, anaphase, telephase

prophase

• nuclear membrane dissolves

• centrioles move to poles + make mitotic spindle (microtubules)

• chromosomes condense and join at centromere

metaphase

• chromosomes line up along metaphase plate (cell equator)

• chromosomes condense and thicken

anaphase

• chromatid separate into single strands

• spindle fibres shorten + pull chromosomes to opposite poles

telophase

• chromosomes decondense

• spindles break down

• nuclear membrane forms

• animal cells = begin cleavage furrow (indenting cytoplasm)

• plant cells = form cell plate to divide cytoplasm

• cytokinesis = daughter cells form, cytoplasm divides

name and describe the stages of mitosis

• same genes

• chromosome from male and female parent

  • may be different variations

• arranged in same order in the dna chromosomes

homologous pairs

• cell division that makes gametes (sex cells)

• reduces number of chromosomes to half (haploid)

• only occurs in eukaryotes who can sexually reproduce

• only occurs in at least diploid organisms

• have TWO divisions

• 1 parent cell = 4 gamete cells

• each gamete holds different genetic info (not identical)

whats meiosis

• interphase before meiosis

• dna replicates

• two identical copies of chromosome within homologous pair is made, attaches at centromere

• copy called sister chromatid

what’s premeiotic interphase

prophase 1

• homologous chromosomes pair together (synapsis)

• chromatids cross over to exchange genetic info at random points (chiasmata)

• pair becomes a tetrad (4 sister chromatids) held together via kinetochore

• centrioles move to opposite poles and spindle fibres appear

metaphase 1

• spindle fibres attach to kinetochore of tetrads

• tetrads line up at metaphase plate

• independent assortment happens

  • chromosome pairs separate randomly

anaphase 1

• tetrad pulls apart, each chromosome moves towards opposite pole

• chromosome pulls apart at kinetochore

• sister chromatids are intact still

telophase 1

• chromosome reach poles

• nuclear membrane reforms

• spindle fibres dissolve

cytokinesis

• cytoplasm + organelles divide

• daughter cells = haploid

• one chromosome from each og homologous pair

• sister chromatid still exist

name and describe stages of meiosis 1

homologous chromosomes pair together

whats synapsis

the random points when chromatids cross over for exchanging genetic info

what’s chiasmata

no interphase/dna replication

• no crossing over

• chromosomes in daughter cells from meiosis 1 are formed as sister chromatids

prophase 2

• chromosome condense

• spindle fibres appear

• centrioles move to opposite ends

metaphase 2

• centromeres divide

• sets of chromatids move to equator

anaphase 2

• chromatids move to opposite poles

telophase 2

• chromosomes unwind, nuclear membrane forms

• makes 4 haploid cells (sperm or ova) after cytokinesis

  • all genetically variable

meiosis 2

diploid spermatogonia → primary spermatocytes → 4 spermatids

sperm formation (spermatogenesis)

diploid oogonia → primary oocytes → 1 egg + 3 polar bodies

• polar bodies all die

egg formation

mistakes during meiosis

trisomy

• fertilized cell has extra chromosome copy

• 3 chromosomes instead of 2

monosomy

• missing chromosome

• 1 chromosome instead of 2

nondisjunction

• chromosome fragment fails to reattach properly

• loss of chromosome segment

• usually deadly/serious disorder

deletion

segment reattaches to complete homologue

duplication

segment reattaches to correct homologue in reverse order

inversion

segment attaches to nonhomologous chromosome

translocation

• cells for testing collected from amniotic fluid

• occurs when fetus is larger

amniocentesis

• obtaining cells for testing via villi lining in uterus

chorionic villus sampling

• organism can only pass one of it’s two genes

• inherited traits determined by two alleles of a gene

• each offspring contains one allele from each parent

law of segregation

• genes found on separate chromosomes are inherited independently of each other

law of independent assortment

dominant alleles will always mask recessive alleles

law of dominance

homozygous = two of same allele (both dom or both rec)

heterozygous = two different alleles (one dom + one rec)

homozygous vs heterozygous

physical/psychological traits of organism

phenotype

genetic makeup/combination of alleles for given trait

genotype

different alleles expressed to produce an intermediate phenotypes

• ex: red x white flower = pink flower

incomplete dominance

two expressed at the same time

• ex: red x white cow = red, white and roan (red and white hair)

codominance

two identically paired x chromosomes (XX)

female sex chromosomes

one x and one y (XY)

male sex chromosomes

evolutionary relationships between species

phylogeny

• diagram showing evolutionary relationships between organisms

• tips = species

• nodes = common ancestor

phylogenic tree

taxonomic group including a single common ancestor + all it’s descendants

clade

• dna profile of species in barcode format

• only 6000 species profiled currently

iBOL method