chapters 12, 14 ,15 - biology genetics

genetic counselors

look at possible diseases in a child before they are born

5 things genetic counselors receive to create a pedigree

1\. general medical history from family (3 gens)

2\. relationship between parents

3\. ages and causes of death in the family

4\. familial diseases

5\. any spontaneous abortions or stillbirths

amniocentesis

\-allows the chromosomal makeup of a fetus be known

\-test is taken once pregenant

\-process

* amniotic fluid is taken from uterus
* cell grows for 2-3 weeks
* examination of cells will detect chromosomal defect

arranging karyotype (3)

* ==size== largest to smallest
* bonding ==pattern==
* ==centeremere== location

heredity

characteristics determined by factors ==passed from one parent== to the ==next==

genetics

the ==study== of heredity

Gregor Mendel

\-==father== of genetics

\-experimented on ==garden peas== because

* small
* easy to grow
* produces hundreds of offspring

roles of fertilization in pea plants

\-^^male^^ part: make ^^pollen^^

\-==female== part: make ==eggs==

selffertilization

when a plant ^^makes a baby^^ with ^^itself^^, identical offspring to itself

true breeding

self pollinating produces offspring ^^identical^^ to itself

* ==successive generation== would be the ==same==

trait

specific characteristic of individual

cross-pollination

^^two^^ different parents

* breed with ==different traits==

how many traits did Mendel study?

==seven==

hybrids

offspring ^^crosses^^ between parents with ^^different^^ traits

P gen

original pair of plants, ==parental== generation

F1

==offspring==, first generation

what happened when Mendel had his F1?

\-each trait was ==only inherited== from ^^one^^ parent

\-other parent seemed to ^^disappear^^ every cross

genes

characteristics from ==one generation== to the ==next==

-controlled by one gene that occurred in t==wo contrasting genes==

-different ==forms== of each trait

alleles

==different== forms of ==genes==

principle of dominance

some alleles are dominant / recessive

-dominant - ABCD

-recessive - abcd

segregation

\-occurs during gamete formation

-allele genes separate

\-each gamete gets one allele from each gene

monohybrid

deals with ^^one trait^^

\-examples

-Tt x tt

-SS x Ss

-mm x Mm

homozygous

^^same^^ alleles (TT, SS, ss, LL)

\-true breeding

heterozygous

^^different^^ alleles (Tt, Ss, Ll)

genotype

^^genetic^^ makeup (TT, Tt, tt)

phenotype

^^physical^^ makeup (tall, short)

genotype ratio (mono)

homo dom : hetero : homo rec

phenotype ratio (mono)

dom : rec

probability

likelihood of passing a ^^specific trait^^

-principles can be used to explain genetic crosses

punnett squares

math problems used to help ^^predict^^ genotype and phenotype ^^combinations^^

-^^past^^ outcomes ^^don’t affect^^ the future

dihybrid

^^crossing^^ with ^^two^^ traits

principle of segregation

^^separation^^ of ^^alleles^^ during gamete formation

principle of independent assortment

genes for ^^different traits^^ segregate ^^independently^^ during gamete formation

foil during dihybrids

^^F^^irst- ^^A^^a^^B^^b

^^O^^uter- ^^A^^aB^^b^^

^^I^^nner- A^^aB^^b

^^L^^ast- A^^a^^B^^b^^

RrYy x RrYy genotype

dom/dom : dom/rec : rec/dom : rec/rec

9 : 3 : 3 : 1

medalion

dominant x recessive

incomplete domincance

\-one allele is not completely dom.

\-hetero. pheno. is between two homo. pheno.

\-written as diferent capital letters

-examples

-R: red, W: white, RW: pink

RR x WW = RW, RW, RW, RW

4 patterns of inheritence

1. medalion- dom/rec
2. incomplete dominance
3. codominance
4. multiple alleles

codominance

phenotype produced by both alleles being clearly expressed

\*use two different capital letters

multiple alleles

\-single gene can have many possible alleles

\-gene with more then one has multiple

\*example- human blood (IA, IB, i)

blood types

O- no antigens, a-b antibodies

A- A antigens, b antibodies

B- B antigens, a antibodies

AB- A-B antigens, no antibodies

agglutination

clumping / clotting of red blood cells

antigen

any substance that causes an immune response (produce an antibody against it)

antibody

protein that’s produced by the body when it detects something harmful

if you give B blood to A receiver…

b antibodies who attack the B antigens causing agglutination

polygenic traits

controlled by two or more genes

-often shows a range of pheno.

-ex. (skin color, eyes, hair)

what can effect gene expression?

environmental condition

phenotype of an organism is ____ determined bu its genotype

partly

X-linked/Sex Linked traits

trait where gene is only on X chromosome

-written with sex cells and superscript

Down Syndrome (trisomy 21)

\-47 chromosomes

-3 chromo in #21

\-distinct features in the eyes and mouth

Turner Syndrome

\-45 chromosomes

\-XO, missing another chromosome

\-sterile female

Super Female (XXX)

\-47 chromosomes

\-limited fertility

Klinefelters (XXY)

\-47 chromosomes

\-sexually underdeveloped male

\-must have two sex chromo. to survive

Barr Bodies

extra sex chromosome permits fetus to develop

XXX + XXY

\-not disruptive

\-all X are inactivated (^^randomly^^), but 1 barr body

\-occurs in early development

\-condensed X chromosomes in act. = darkly stained

deletion

housing part/whole chromosome

\
ACDE

duplication

repeat part or all chromosome

\
ABBCDE

inversion

goes within same chromosome switch locals

\
ACDBE

translocation

genes break off and attach to another non-homologous chromosome

\
ABC XYZ