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33922013
Unit 3
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Biology Mind Map on Unit 3, created by dumb himbo on 14/10/2021.
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Unit 3
CH 11: Sexual Reproduction and Meiosis
SEXUAL LIFE CYCLES
HAPLOID
HAPLOID CELLS
1 copy of each chromosome
GAMETES
DIPLOID
DIPLOID CELLS
2 copies of each chromosome
GERMLINE CELLS
undergo meiosis and reduce chromosome from 2n to 1n into gametes
ZYGOTE
undergoes mitosis to continue to produce diploid cell
to become a viable organism/offspring; needs to get bigger thru mitosis (growth)
in most animals diploid dominates
SEXUAL REPRODUCTION
meiosis and fertilization constitute a cycle of reproduction
inherit 23 chromosomes from both parents
MOTHER
MATERNAL HOMOLOGUE
EGG
XX
FATHER
PATERNAL HOMOLOGUE
SPERM
XY
male sperm determines gender of offspring
sperm and egg fuse for fertilization to take place resulting in a zygote
FERTILIZATION restores diploid # (1n plus 1n equals 2n)
MEIOSIS
2 ROUNDS OF DIVISION
MEIOSIS I
PROPHASE I
chromosomes condense, nuclear envelope disappears, spindle apparatus forms, synapsis, crossing over
SYNAPIS
homologous chromosomes become closely associated
CROSSING OVER
genetic material exchange
allows for genetic variety
METAPHASE I
chiasmata hold homologues together, homologues align at metaphase plate, spindles attach to homologues
ANAPHASE I
chiasmata break, chromosomes pulled to opposite poles (each pole has complete haploid), separates homologues
TELOPHASE I
nuclear envelope reforms, sister chromatids not identical (diversity)
MEIOSIS II
PROPHASE II
chromosomes
METAPHASE II
ANAPHASE II
TELOPHASE II
4 daughter cells (1 copy of each chromosome)
ERRORS OF MEIOSIS
ANEUPLOID GAMETES
missing or extra chromosomes in gametes
NONDISJUNCTION
genetic disorder, too many or too less chromosomes
MEIOSIS FUNCTION
production of gametes
mitosis function is growth and repair
MEIOSIS FEATURES
(compare mitosis and meiosis)
synapsis + crossing over
sister chromatids joined in meiosis I
kinetochores of sister chromatids attach to same pole
DNA replicating suppressed
independent assortment
2n to 1n
also referred to as REDUCTION DIVISION
chromosome #s reduce, divides cell into four daughter cells
CH 12: Patterns of Inheritance
PRINCIPLE OF INDEPENDENT ASSORTMENT
PRINCIPLE OF SEGREGATION
2 alleles for a gene segregate during gamete formation (meiosis)
rejoined at random, one from each parent, during fertilization
in dihybrid cross, alleles for each gene assort differently
traits separate independently in gamete formation
EPIGENTICS
EPISTASIS
behaviour of gene products change ratio
how genes react w/ other molecules
POLYGENIC INHERITANCE
PLEIOTROPHY
GENE
ALLELE
DIHYBRID CROSS
MONOHYBRID CROSS
*punnet square
F1 GENERATION
F2 GENERATION
breed F1 offspring
offspring in first cross
two traits; four outcomes ---> 16 outcomes
different forms of the same gene
segment of DNA found on chromosome, codes for protein
DOMINANT
INCOMPLETE DOMINANCE
CODOMINANCE
heterozygote shows both traits (co means with)
RECESSIVE
masked by dominant allele
HOMOZYGOUS RECESSIVE
HOMOZYGOUS DOMINANT
HETEROZYGOUS
GENOTYPE
PHENOTYPE
physical characteristic
genetic makeup
blend, alleles do not mask eachother
dominant allele masks recessive allele
CH 13: Chromosomes, Mapping, and the Meiosis-Inheritance Connection
SEX LINKAGES
sex linked conditions reside on X or Y chromosome
certain genetic disease affect males to a greater degree than females
X CHROMOSOME
is larger than Y chromosome
more sex linked conditions because it's bigger
in FEMALES, one X chromosome is inactivated
carries essential genes
GENETIC MOSAICS
Y CHROMOSOME
smaller than X chromosome, not a lot of info
CHROMOSOME THEORY EXCEPTIONS
GENOMIC IMPRINTING
"Which parent contributed the alleles?"
CH 14: DNA: The Genetic Material
DNA STRUCTURE
DNA is a nucleic acid
nucleic acid is made up of NUCLEOTIDES
NUCLEOTIDES
are made up of:
DEOXYRIBOSE
PHOSPHATE GROUP
NITROGENOUS BASE
PURINES
Adenine and Guanine
PYRIMIDINES
Thymine and Cytosine
Uracil (RNA)
COMPLEMENTARY BASE PAIRING
A to T
AMOUNT OF A = AMOUNT OF T
G to C
AMOUNT OF G = AMOUNT OF C
HYDROGEN BONDS joins nitrogenous bases
"easy to make, easy to break"
PHOSPHODIESTER BONDS
joins two nucleotides
DNA is a double stranded molecule
"COOLING STRAND"
"TEMPLATE STRAND"
*template means pattern
used to make mRNA
CELLS REPLICATE DNA TO REPRODUCE
DNA is replicated during SYNTHESIS
DNA is made in 5 PRIME TO 3 PRIME direction
DNA POLYMERASE
ENZYMES RESPONSIBLE FOR MAKING DNA
CH 15: Genes and How They Work
CENTRAL DOGMA OF BIOLOGY
information flows in one direction
DNA ---> RNA
RNA ---> PROTEIN
EXCEPTION:
RETROVIRUSES use the enzyme, REVERSE TRANSCRIPTASE to convert RNA to DNA
PROTEIN SYNTHESIS
TRANSCRIPTION
RNA POLYMERASE
used to make RNA
NOT a good proofreader
TRANSLATION
tRNA, TRANSFER RNA, transfers amino acids to ribosomes
RIBOSOMES: site of protein synthesis
ribosomes are made of two subunits
peptide bond forms between amino acids on protein
IMPORTANT FOR PROTEIN SYNTHESIS:
mRNA
tRNA
rRNA
DIFFERENCES IN RNA AND DNA
RNA
single stranded
A-U
ribose
DNA
double stranded
A-T
deoxyribose
CODONS
STOP CODONS
terminates translation; stops process
UUA, UGA, UAG
START CODONS
start of translation
AUG
a codon is 3 NUCLEOTIDES in a row
code is degenerate; multiple codons code for the same amino acid
"WOBBLE EFFECT"
mutation of the third nucleotide does not affect amino acid
MUTATIONS
POINT MUTATION
alters a single base, can be SPONTANEOUS or INDUCED
SPONTANEOUS MUTATIONS
cause: DNA polymerase proofreads incorrectly
INDUCED MUTATIONS
cause: radiation, chemicals
FRAMESHIFT MUTATION
more profound effects than point mutation
changes reading frame
the addition or deletion of a base
TRIPLET REPEAT EXPANSION MUTATION
CHROMOSOMAL MUTATIONS
changes structure
DELETION
genes deleted from chromosome, chromosome lacks gene
DUPLICATION
INVERSION
genes become inverted (flip-flopped)
RECIPROCAL TRANSLOCATION
moving genes from one place to another
genes duplicated, multiple copies of genes on chromosome
EUKARYOTES
DNA in EUKARYOTES is LINEAR
PLANTS, ANIMALS, FUNGI, AND PROTISTS
PROKARYOTES
DNA in PROKARYOTES is CIRCULAR
BACTERIA and ARCHEA
SICKLE CELL DISEASE
single point mutation of one base
causes red blood cell to take on a sickle shape
spleen filters out sickle shaped red blood cells
person does not have enough red blood cells to carry oxygen to cells
person gets anemia, anemic people are tired
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