Biology Review
UNIT 1
Module 1 : Mitosis meiosis sex +genetic
, , ,
variation
Genetic into is transmitted from
·
.
one generation to another through mitosis meiosis, ,
+ fertilization
vocabulary
sexual reproduction -
2 parents give rise to Offspring that have unique combinations of genes inherited from the
2 parents
meiosis creates haploid from diploid cells
fertilization combines 2 haploid cells back to diploid
asexual reproduction a single individual passes genes to offspring wout fusion of gametes
-
genetic variation only arises from mutations (slow) ; beneficial in non-changing environment where clones are favored
a clone is a Identical individuals from same parent
group of genetically < produced
asexually (mitosis)
diploid contains 2 sets of chromosomes one from each parent (2n) 2 haploids unite during fertilization
-
,
haploid-contains only I set of chromosomes (n) to make a diploid
homologous chromosomes the 2 chromosomes in each pair
-
sister chromatids-joined copies of the original chromosome, homologous pair
attachedbyCentromereareatid S-chromatids from different chromosomes
paternal
maternal
↓ replication
that are part of a homologous pair homologous pair
gene-DNA that specifies RNA and sometimes proteins
non-sister chromatids
allele alternative versions of genes Sister chromatids
-
jocus-the place on a chromosome where a particular gene is located
cell mitosis used for :
cycle :
Interphase (90%) : G (growth) .
<
S(synthesis) <
G (growth) · normal growth, repair ,
maintenance
cell division (10%) : mitosis
-
+
meiosis
a sexual reproduction
·
I division 2 divisions · reproduction when
sexual
zidentical 4 haploid , fertilized e99 (new zygote/growing
daughter cells varied embryo) gets bigger specialized
-
genetically + more
daughter cells
minase
telophase cytokinesis
aa
prometaphase
daughter
2 identical
cells
S
nuclear envelope
chromatin condenses chromosomes start
chromosomes Sister chromatids cell split (via cell
· O
· · ·
·
centrosomes begin to
· disappears alian on metaphase move to opp poles .
condensed wall for plants or
more to poles spindle
-
Kinetchores attatch plate·
microtubules
to get less
cleavage
·
form to chromosomes centrosomes on stretched across cell 2
·
nuclei present furrow for
nucleolus disappears
·
non-kinetichore animals
·
opposite poles envelope
·
&
nuclear
microtubules form &
microtubules reforms
+ expand cell
stretched across
cell
meiosis 1 :
origin of genetic variation
Helophase I
metaphase mutation the original source of
&
prophase I ·
57
-
variation -
mutations give rise to
& >
-
> 2 haploid cells new alleles
·
3 mechanisms that contribute to
·
chromatin condenses ·
tetrads align genetic variation
chromosomes separa
into chromosomes at metaphase · movement of Independent assortment
·
homologous chromosomes plate and pull towards
pair up (tetrads) diploids (2n) ·
opposite poles homologous chromosomes <
homologous chromosomes
Orient
·
chromatids of homologous continues until there are 2 randomly during metaphase I
of meiosis
chromosomes swap (crossing
over
haploid set of chromolids at =
crossing over-recombination
each pole scrossing over btwn non-
O
spindle fibers form + attatch
to centromeres to move tetrads ·results in 2 haploid cells Sisterchromatidsproducesrecombinis
around
Inherited from each parent
↓ 3 random fertilization
meiosis It : < sperm can fuse w/ any egg
Prophase #I
*
metaphase #I
-
Y varied
> 4 genetically
haploid cells
spindle fibers form
·
sister chromatids
· ·
centromeres ·
separated sister
chromosomes more toward
·
arranged & metaphase separate chromatids arrive
plate chromatids more at opposite poles
metaphase plate ·
nuclei forms around
cells are haploid but still
Sisterchromatids towards optio state
·
·
·
poles as individual chromatids
have sister chromatids that
chromosomes ·
cytokinesis separates
must be divided
cytoplasm
, sexual reproduction asexual reproduction cell division :
·
living organisms
are
self-renewing
genetic variation only cell division reproduces entire
othereshufflingofgenesention organisms
· in
· unicellular organism
arises from mutations 8
multicellular organisms use cell division
produces lots of genetic accumulation of mutations development from fertilized egg
i growth
·
variation in the next generation is a slow process
·
variation of offspring is beneficial in a non- ⑧ renewal +
repair
beneficial in
changing changing environment,
environments when clones are favored
novel gene combinations
·
are made
evolutionary processes ,
·
especially natural selection ,
can
act on this variation + select
for favorable combinations Of
genes
Module 2 : Mendelian Genetics - chromosomal Inheritance
Inheritance patterns of
·
phenotypes can be predicted based on Mendelian Inheritance -
chromosomal linkage
vocabulary Care diploid): have 23 pairs of chromosomes
O
somatic cell-body cells
·
gamete-reproductive cells (are haploid) ; each cell carries only one copy of each chromosome
homozygous/true breeding a diploid organism w/ 2 Identical alleles for a gene (or character) < P, pp
-
· -
a diploid
organism w/ 2 different alleles for a gene
·
heterozygous
⑧ -
⑧
dominant the allele that is
- expressed as a single allele in the
phenotype of a heterozygote
fully
recessive the allele whose heterozygote (needs 2 copies to express It)
phenotypic effect is not observed in a
-
·
organisms that are heterozygotes or hybrid for 1 character (gene)
monohybrid-a cross btun
⑧
dihybrid-a cross btwn F dihybrids can determine whether 2 characters are transmitted to offspring as a package
·
, ,
or ind . dihybrids are heterozygous for both characters produced
by crossing 2 true breeding parents ,
test cross-cross an individual of unknown
genotype w/ a homozygous recessive one to determine If the unknown
·
genotypeIs homozygous dominant or heterozygous
IfIf someoffspring are dominant
all
phenotype homozygous
=
offspring are recessive =
heterozygous
·
genotypic rato-ratio of the genetic makeup (PP : Pp : pp)
·
phenotypic ratio-ratio of observational characteristics resulting from the genotype+ environment (purple white
:
Mendel's 1st Law of segregation
& for each character an organism Inherits 2 alleles, I from each parent
,
①
alternative
& versions of "genes" (alleles) account for variations in inherited characteristics
alleles separate from each other in the formation of the gametes (the gametes unite at random
·
during fertilization)
combinations of sperm -
< possible egg in fertilization can be shown
using punnett square
Mendel's 2nd Law of segregation
·
each pair of alleles line up ind. of other alleles during meiosis
alleles controlling
one trait do not affect the transmission of alleles for another trait
·
complex Inheritance (Mendel didn't account for these
complete dominance occurs when phenotypes of the heterozygote and dominant homozygote are
·
-
Identical ; only need I dominant allele
Incomplete dominance the phenotype of F, hybrids is somewhere btwn the phenotypes of the 2
· -
parental varieties ; one allele does not completely dominant (ex : F hubvids are pink from red-white flowers ,
codominance both alleles are expressed
· -
multiple alleles-genes can have multiple alleles (each diploid Individual still only carnes 2 diff
·
alleles but a
variety of alleles can make up these 2)
>
ex: human blood groups are determined by 3 alleles for the enzyme () that attatches A or 13 carbs
to red blood cells : 17 13 i
leading to blood groups A , B AB,
, ,
,
-
universal donor-ii(o)
universal recipient-1B (AB)
-
·
polygenetic Inheritance -
additive effect of 2 or more
genes on a single phenotype
seX : height skin color population along a continuum and are controlled by mult.
-
+ straits vary in a
the
genes -
environment
sex-linked traits the human y chromosome carries few genes and many are related to sex
· -
determination; genes on X chromosomes are called X-linked genes and many are unrelated to sex , all genes on X
or y are sex-linked
* is female XY Is male >Sky gene on y causes male development
YX ,
linked genes follow a specific pattern of Inheritance
UNIT 1
Module 1 : Mitosis meiosis sex +genetic
, , ,
variation
Genetic into is transmitted from
·
.
one generation to another through mitosis meiosis, ,
+ fertilization
vocabulary
sexual reproduction -
2 parents give rise to Offspring that have unique combinations of genes inherited from the
2 parents
meiosis creates haploid from diploid cells
fertilization combines 2 haploid cells back to diploid
asexual reproduction a single individual passes genes to offspring wout fusion of gametes
-
genetic variation only arises from mutations (slow) ; beneficial in non-changing environment where clones are favored
a clone is a Identical individuals from same parent
group of genetically < produced
asexually (mitosis)
diploid contains 2 sets of chromosomes one from each parent (2n) 2 haploids unite during fertilization
-
,
haploid-contains only I set of chromosomes (n) to make a diploid
homologous chromosomes the 2 chromosomes in each pair
-
sister chromatids-joined copies of the original chromosome, homologous pair
attachedbyCentromereareatid S-chromatids from different chromosomes
paternal
maternal
↓ replication
that are part of a homologous pair homologous pair
gene-DNA that specifies RNA and sometimes proteins
non-sister chromatids
allele alternative versions of genes Sister chromatids
-
jocus-the place on a chromosome where a particular gene is located
cell mitosis used for :
cycle :
Interphase (90%) : G (growth) .
<
S(synthesis) <
G (growth) · normal growth, repair ,
maintenance
cell division (10%) : mitosis
-
+
meiosis
a sexual reproduction
·
I division 2 divisions · reproduction when
sexual
zidentical 4 haploid , fertilized e99 (new zygote/growing
daughter cells varied embryo) gets bigger specialized
-
genetically + more
daughter cells
minase
telophase cytokinesis
aa
prometaphase
daughter
2 identical
cells
S
nuclear envelope
chromatin condenses chromosomes start
chromosomes Sister chromatids cell split (via cell
· O
· · ·
·
centrosomes begin to
· disappears alian on metaphase move to opp poles .
condensed wall for plants or
more to poles spindle
-
Kinetchores attatch plate·
microtubules
to get less
cleavage
·
form to chromosomes centrosomes on stretched across cell 2
·
nuclei present furrow for
nucleolus disappears
·
non-kinetichore animals
·
opposite poles envelope
·
&
nuclear
microtubules form &
microtubules reforms
+ expand cell
stretched across
cell
meiosis 1 :
origin of genetic variation
Helophase I
metaphase mutation the original source of
&
prophase I ·
57
-
variation -
mutations give rise to
& >
-
> 2 haploid cells new alleles
·
3 mechanisms that contribute to
·
chromatin condenses ·
tetrads align genetic variation
chromosomes separa
into chromosomes at metaphase · movement of Independent assortment
·
homologous chromosomes plate and pull towards
pair up (tetrads) diploids (2n) ·
opposite poles homologous chromosomes <
homologous chromosomes
Orient
·
chromatids of homologous continues until there are 2 randomly during metaphase I
of meiosis
chromosomes swap (crossing
over
haploid set of chromolids at =
crossing over-recombination
each pole scrossing over btwn non-
O
spindle fibers form + attatch
to centromeres to move tetrads ·results in 2 haploid cells Sisterchromatidsproducesrecombinis
around
Inherited from each parent
↓ 3 random fertilization
meiosis It : < sperm can fuse w/ any egg
Prophase #I
*
metaphase #I
-
Y varied
> 4 genetically
haploid cells
spindle fibers form
·
sister chromatids
· ·
centromeres ·
separated sister
chromosomes more toward
·
arranged & metaphase separate chromatids arrive
plate chromatids more at opposite poles
metaphase plate ·
nuclei forms around
cells are haploid but still
Sisterchromatids towards optio state
·
·
·
poles as individual chromatids
have sister chromatids that
chromosomes ·
cytokinesis separates
must be divided
cytoplasm
, sexual reproduction asexual reproduction cell division :
·
living organisms
are
self-renewing
genetic variation only cell division reproduces entire
othereshufflingofgenesention organisms
· in
· unicellular organism
arises from mutations 8
multicellular organisms use cell division
produces lots of genetic accumulation of mutations development from fertilized egg
i growth
·
variation in the next generation is a slow process
·
variation of offspring is beneficial in a non- ⑧ renewal +
repair
beneficial in
changing changing environment,
environments when clones are favored
novel gene combinations
·
are made
evolutionary processes ,
·
especially natural selection ,
can
act on this variation + select
for favorable combinations Of
genes
Module 2 : Mendelian Genetics - chromosomal Inheritance
Inheritance patterns of
·
phenotypes can be predicted based on Mendelian Inheritance -
chromosomal linkage
vocabulary Care diploid): have 23 pairs of chromosomes
O
somatic cell-body cells
·
gamete-reproductive cells (are haploid) ; each cell carries only one copy of each chromosome
homozygous/true breeding a diploid organism w/ 2 Identical alleles for a gene (or character) < P, pp
-
· -
a diploid
organism w/ 2 different alleles for a gene
·
heterozygous
⑧ -
⑧
dominant the allele that is
- expressed as a single allele in the
phenotype of a heterozygote
fully
recessive the allele whose heterozygote (needs 2 copies to express It)
phenotypic effect is not observed in a
-
·
organisms that are heterozygotes or hybrid for 1 character (gene)
monohybrid-a cross btun
⑧
dihybrid-a cross btwn F dihybrids can determine whether 2 characters are transmitted to offspring as a package
·
, ,
or ind . dihybrids are heterozygous for both characters produced
by crossing 2 true breeding parents ,
test cross-cross an individual of unknown
genotype w/ a homozygous recessive one to determine If the unknown
·
genotypeIs homozygous dominant or heterozygous
IfIf someoffspring are dominant
all
phenotype homozygous
=
offspring are recessive =
heterozygous
·
genotypic rato-ratio of the genetic makeup (PP : Pp : pp)
·
phenotypic ratio-ratio of observational characteristics resulting from the genotype+ environment (purple white
:
Mendel's 1st Law of segregation
& for each character an organism Inherits 2 alleles, I from each parent
,
①
alternative
& versions of "genes" (alleles) account for variations in inherited characteristics
alleles separate from each other in the formation of the gametes (the gametes unite at random
·
during fertilization)
combinations of sperm -
< possible egg in fertilization can be shown
using punnett square
Mendel's 2nd Law of segregation
·
each pair of alleles line up ind. of other alleles during meiosis
alleles controlling
one trait do not affect the transmission of alleles for another trait
·
complex Inheritance (Mendel didn't account for these
complete dominance occurs when phenotypes of the heterozygote and dominant homozygote are
·
-
Identical ; only need I dominant allele
Incomplete dominance the phenotype of F, hybrids is somewhere btwn the phenotypes of the 2
· -
parental varieties ; one allele does not completely dominant (ex : F hubvids are pink from red-white flowers ,
codominance both alleles are expressed
· -
multiple alleles-genes can have multiple alleles (each diploid Individual still only carnes 2 diff
·
alleles but a
variety of alleles can make up these 2)
>
ex: human blood groups are determined by 3 alleles for the enzyme () that attatches A or 13 carbs
to red blood cells : 17 13 i
leading to blood groups A , B AB,
, ,
,
-
universal donor-ii(o)
universal recipient-1B (AB)
-
·
polygenetic Inheritance -
additive effect of 2 or more
genes on a single phenotype
seX : height skin color population along a continuum and are controlled by mult.
-
+ straits vary in a
the
genes -
environment
sex-linked traits the human y chromosome carries few genes and many are related to sex
· -
determination; genes on X chromosomes are called X-linked genes and many are unrelated to sex , all genes on X
or y are sex-linked
* is female XY Is male >Sky gene on y causes male development
YX ,
linked genes follow a specific pattern of Inheritance
