Genetics test Flashcards
what are the nitrogen bases?
A - adenine
T - thymine
C - cytosine
G - guanine
what nitrogen bases pair together
A pair with T
C pair with G
interphase
the cells spend most of there life there replicating DNA and make proteins etc.
prophase
chromatids become tightly colied (chromosomes)
metaphase
spindle fibres attach to the chromosomes pulling into a line along the middle of the cell
anaphase
sister chromatids pull apart by spindle fibers and pulled towrad the centroies
telophase
spindle fibres and centrioles disappear
nuclear membrane starts to reform
nucleolus form inside the nucleus
cytokinesis
2 seperate cells or 2 identical daugther cells
what is the purpose of mitosis
growth and replacing cells
prophase |
homologous chromosomes are held tightly together while lined up segements of the chromosomes will be exchanged
metaphase |
pairs of homologous chromosomes line up along equator of the cell
the spindle fibers attach to the centormere
anaphase |
chromosomes seperate and move to opposite poles
sister chromatids are still connected
telophase |
chromosomes begin to uncoil and spindle fibres disappear
a nucleus membrane form around each cell
prophase ||
chromosomes condense and a new set of spindle fibers form
metaphase ||
chromosomes line up along th eequator of the cell
anaphase ||
the sister chromatids are pulled to the opposite poles
and become chromosomes
telophase ||and cytokinesis
nuclei form at opposite poles and make 4 daugther cells
differance between mitosis and meiosis
mitosis
stomacta (body cells)
2 diploid cells
identical
meiosis
sex clls
4 haploid body cells
NOT identical
purpose of meiosis
genetic reduction
genetic recombination
chromatids
one-half of a duplicated chromosomes
sister chromatid
one of two chromosomes that are genetically identical and held together with a centromere
centromere
the place where 2 sister chromosomes are held together
homologous pair
paired chromosomes similar in size, shape, gene arrangements and gene formation
crossing over
the exchange of genetic material
haploid (N)
refers to the number of chromosomes in a gamete (23)
diploid (2N)
refers to twice the number of chromosomes in a gamete (46)
deletion
a segement of the chromosome is deleted
duplication
a segment of the chromosome is duplicated
inversion
a segment of the chromosome is inverted
translocation
when a segment relocates to another spot in the chromosomes
Klinefelter syndrome
sex chromosome XXY
extra X chromosome
sexual immaturity
breast swelling
Turner syndrome
sex chromosome OX
lose of X chromosome
short stature
sexually underdevelopped
webbed neck
Down syndrome
autosome trisomy 21
almond-shaped eyes
flatten face
short stature
karyotypes charts
used to examine an individual’s chromosomes
autosomes vs. sex chromosomes
autosomes
a chromosome that ISN’T INVOLVED in the sex of a organism
sex chromosome
a chromosome that is involved in the sex of an organism(X,Y)
in virto fertilization (IVF)
used when a woman has blocked fallopian tubes
immature eggs combined with sperm in a lab
or
injecting the sperm into the egg
advantages of IVF
increases conceiving
you have control over timing
disadvantages of IVF
birth defects
expensive
ethical issues of IVF
the quality of consent obtained from both parties
the choice of embryos for traits
law of segregation
traits determined by pairs of alleles that segregate during meiosis
law of independent assortment
during gamete formation, the 2 alleles for one gene assort the allele
non-disjunction
the failure of homologous chromosomes to pair to one pole to separate during meiosis
synapsis
the alleging of homologous chromosomes during prophase 1
allele
the different forms of the same gene
homozygous
an organism with 2 identical alleles
BB or DD
heterozygous
an organism with 2 different alleles
Bb or Dd
dominant
the form of a trait that ALWAYS appears if they have the allele
Rr or RR
recessive
the form of trait that apears if they have TWO alleles for it
rr
blood types
A B AB O
AA, AO BB, BO AB. OO
Aint-B Aint-A NONE Aint-AB
Incomplete dominance
mixing the colours
white + red = pink
co-dominance
the pattern of inheritance where both alleles are expressed AT THE SAME TIME
white + red = white with red spots
complete dominance
when only one allele can be shown
red + red = RED
