biology notes genetics review

7/21/2019 Biology Notes Genetics Review

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Emma CummingsBiology: Unit 1 – Genetics

ReviewDNA structure and function

- Double helical- Each strand is comosed o! nucleotides made o!:

o  " sugar #deo$yribose%

o  " negatively charged hoshate grouo  " nitrogenous base:

 "denine #"% – Double ringed urine

Guanine #G% – Double ringed urine

Cytosine #C% – &ingle ringed yrimidine

'hymine #'% – &ingle ringed yrimidine

- Bonds between the sugar and hoshate bac(bone – calledhoshdiester #strong covalent bonds%

- Bonds holding nitrogen gases together – hydrogen bonds- " urine always binds with a yrimidine

o  " ) ' #Double hydrogen bond%

o C - G #single hydrogen bond%

DNA replication

 Called - &emi-Conservative relication:

&te 1% Un*iing+ hydrogen bonds are bro(en

&te ,% Base airing: ree nucleotides #that are resent in the cell% air u withunaired nucleotides.

&te /% 0ydrogen bonds re!orm between new base airs.

Result: two identical molecules o! D".

Biological drawings – Notes

Mitosis

Interphase

- Chromatin starts as anindistinguishable mass o!D"2 in that mass+ there

are34 strands. 5ust be!oremitosis begins+ these strandso! chromatic relicate+condense and coil to become34 chromosomes

- 6ther cell organelles dulicate- ot o!!icially art o! mitosis

#7get ready8 stage%

- 9ade o! u G1+ &+ and G,hases.

- G1 #ga 1%: Cell carries outactivities to reare it !or thene$t hase. Raid growth andmetabolic activity mar( the G1hase.

- & #synthesis%: D" isrelicated during this hase.'he cell will either rest a!terthis hase or continue on tothe G, hase.

- G, #ga ,%: Cell is rearing!or division.

7/21/2019 Biology Notes Genetics Review

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Emma CummingsBiology: Unit 1 – Genetics

Review- 'he cell divides because it is

too large to be controlled bythe nucleus+ to relacedamaged cells etc.

Prophase

- Chromosomes coil andcondense and become visibleunder a microscoe

- uclear membrane andnucleoli disaear 

- 'wo airs o! centrioles aear and move towards the olesaart as sindle !ibers !ormbetween them.

Metaphase

- &indle attach to thecentromere

- Chromosomes are ushedand ulled by the sindle!ibers+ and are eventuallyarranged along the cellsmidline+ or e;uator.

Anaphase

- &indle !ibers shorten andull2 chromosomes searateat the centromeres+ ullingaart the sister chromatidsand roducing daughter

chromosomes- Daughter chromosomes

migrate to oosite oles

Telophase

- Chromosomes uncoiled toroduce chromatin

- &indle !ibers disaear+nuclear membrane andnucleoli reaear 

- Cell starts to inch in themiddle in rearation !orcyto(inesis+ or cell division.

Cytokinesis

- Cell continues to inch untiltwo daughter cells are !ormed

- <n lant cells+ this is when thecell late is !ormed+ it is madestronger once the cytolasmdevides.

Meiosis – Notes

Gaetogenesis

Males ! "peratogenesis

- E;ual division o! cytolasm- &erm cells are streamlined

!or movement+ they cannotcarry e$cess weight

- 9a(e more se$ cells than

!emales#eales ! $ogenesis

- Cytolasm does not dividee;ually a!ter each division

- 6ne daughter cell called theootid receives most o! thecytolasm

- Uses the e$tra cytolasm andorganelles !or !uture cell

division #in !ertili*ation%- 6ther cells called olar bodies

die- 6nly one ovum is roduced

by meiosis

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A%noral Meiosis &Non!dis'unction( – Notes

Mendelian genetics &onohy%rid and dihy%rid crosses ) test Crosses( –*e+iew fro notes

Punett s,uares – Notes

Alternate fors of inheritance &Codoinance- Incoplete doinance-Mulitple alleles- .!linkage( ! Notes

=edigrees

Autosoal *ecessi+e

- ot >-lin(ed- 'wo recessive alleles are re;uired !or the child to have this trait

Autosoal Doinant

- ot >-lin(ed- 6nly one allele will give the child this trait

.!linked *ecessi+e

- >-lin(ed- 'wo recessive alleles are re;uired !or the child to have this trait

.!linked Doinant

- >-lin(ed- 6nly one allele will give the child this trait

#Review: D" e$traction+ corn genetics+ blood tying+ and dragon genetics%