Inheritance II Flashcards
what is the order of mitosis?
end of interphase
prophase
prometaphase
metaphase
anaphase
telophase
(cytokinesis)
what is the difference between having cytokinesis in mitosis and not?
interphase to telophase is nuclear division (Mitosis)
interphase to cytokinesis is cell division
what are two centrioles called?
one centomere (aster)
what happens during the end of interphase?
DNA is already dulpicated
chromosomes are decondesed (unravelled)
what happens during prophase?
chromosomes condense and become visible
centromes seperate and begin to form spindle
- centrioles make spindle fibres
what happens during prometaphase?
nuclear membrane breaks down
chromosomes attach to spindle fibres
what happens during metaphase?
chromosomes line up at the equator of the spindle
what happens during anaphase?
centromeres split and chromatids are pulled to the poles of the cell
what happens during telophase?
nucleae membranes reform
a furrow starts to divide the cytoplasm
what happens during cytokinesis
follows mitosis
chromosomes decondense (unravel)
nuclear membranes full formed
division of cytoplasm is complete
two genetically identical daughter cells made
label this end of interphase diagram
label this prophase diagram
label this prometaphase diagram
label this metaphase
label this anaphase diagram
label this telophase diagram
label this cytokinesis diagram
what is the point of mitosis?
make new cells to replace dead/damaged cells (i.e. repair)
to make new cells grow
where in the body does mitosis happen and which cells are involved?
mitosis occurs in all tissues of the body
some aread have a high rate of mitosis - skin, blood (red blood cells live for about 3 months), intestine cells (cells lining villi)
some areas have a very low rate of mitosis - neurones
complete this diagram to show the chromosomes in each daughter cell
what is the diploid number of the parent cell?
diploid number of parent cell = 4
how does the increase in temperature affect thetime taken for cell division to occur?
the time taken decrease
starting with one cell at 250, how many cells would there be after:
2 hours
8 hours
2 hours = 2
8 hours = 16
how many sets of chromosomes does a diploid have?
2
how many sets of chromosomes does a haploid have?
1
what are haploids?
egg or sperm
why is meisos needed when we make gametes?
making gametes (haploid - 23 chromosomes) from diploid cells (46 chromosomes)
complete this diagram of how to make gametes
what is the order of meisos?
interphase 1
prophase 1 and prometaphase 1
metaphase 1
anaphase 1
telophase and cytokinesis 1
prophase 2 and prometaphase 2
metaphase 2
anaphase 2
telophase and cytokinesis 2
what happens during interphase 1?
chromosomes duplicate (interphase)
what happens during prophase 1 and prometaphase 1?
prophase 1:
chromosomes condense and become visible
chromosomes pair up (in homologous pairs)
crossing-over of DNA occurs
prometaphase 1:
nuclear membrane breaks down
spindle beings to form
what happens during metaphase 1?
chromosomes pairs align on equator of spindle
chromosomes independantly assorted on spindle (randomly placed)
what happens during anaphase 1?
spindle fibres contract, pulling homologous chromosomes to poles of cell
what happens during telophase 1 and cytokinesis 1?
telophase 1:
nuclear membrane reform
cytokinesis 1:
furrow forms and seperates the two daughter cells
what happens during prophase 2 and prometaphase 2?
prophase 2:
chromosomes are already condensed
prometaphase 2:
nuclear membranes break down
spindles begin to form
what happens during metaphase 2?
chromosomes align at equator of spindle
(the difference between metaphase 2 and mitosis is that crossing-over has occured)
what happens during anaphase 2?
spindle fibres contract pulling the chromatids to the poles of the cell
what happens during telophase 2 and cytokinesis 2?
telophase 2:
nuclear membranes form
chromosomes decondense
cytokinesis 2:
furrows seperate 2 x 2 daughter cells
4 haploid cells have been produced
label this interphase 1 diagram
label this prophase 1 and prometaphase 1 diagram
label this metaphase 1 diagram
label this anaphase 1 daigram
label this telophase 1 and cytokinesis 1 diagram
recall the prophase 2 and prometaphase 2 diagram
recall the metaphase 2 diagram
label this anaphase 2 diagram
label this telophase 2 and cytokinesis 2 diagram
what is chiasmata?
sites of crossing over
how is cell division 2 different to cell division 1?
genetically identical daughter cells are not made in cell division 2 because of crossing over
what happens as a result of crossing over?
chromosomes are recombinant due to crossing over
what happens as a result of independant assortment?
each new cell has a mixture of paternal and maternal chromosomes
what is the result of meiosis?
4 haploid cells, each with ie set (23) of chromosomes
the 4 new cells are not genetically identical
where does mitosis take place?
whole body
where does meiosis take place?
ovaries
testes
how many rounds of cell division are there in mitosis?
one
how many rounds of cell division are there is meiosis?
2
what happens to the chromosome number in mitosis?
stays the same
46 –> 46
what happens to the chromosome nmber in mieosis?
halved
46 –> 23
are parents and daughter cells genetically identical in mitosis?
yes
are parents and daughter cells genetically identical in meiosis?
no
are daughter cells identical in mitosis?
yes
are daughter cells identical in mieosis?
no
are cancer cells mitosis or meiosis?
mitosis
are cells in the testes forming sperm mitosis or meiosis?
meiosis
are cells in the lining of the small intestine to replace lost cells mitosis or meiosis?
mitosis
are the cells in the bone marrow dividing to form red and white blood cells mitosis or meiosis?
mitosis
are cells in anther of a flower diving to form pollen mitosis or meiosis?
meiosis
is a zygote dividing to form an embryo mitosis or meiosis?
mitosis
is this mitosis or meiosis? why?
meiosis
chromosomes have halved
is this mitosis or meisis? why?
mitosis
chromsmes have stayed the same
what is variation?
(small) differences between members of the same species
what is genetic variation?
differences caused by genes inherited from parents
what is environmental variation?
differences caused by the environment
complete this genetic variation tree diagram
each homologous chromosome has the same ……………
(e.g. ….)
type of genes
(e.g. both have genes for eye colour, earlobe, shape etc…)
chromosomes from father and mother might have different ………..
(e.g. ….)
versiones of genes ( = alleles)
(e.g. alleles for brown or blue eyes)
some alleles are ….. and over other alleles (e.g. the “brown eye” allele is …… over the “blue eye” allele)
dominant
dominant
in humans, how many chromososmes are from the mother and how many are fro the father?
23 chromosomes from mother
23 chromosomes from father
allele
a version of a gene
dominant allele
only 1 copy is necessary for characteristic to be shown
recessive allele
2 recessive alleles are needed (no dominant allele present) for characteristic to be shown
genotype
the genetic make-up
i.e. which alleles are present
homozygous
having 2 identical alleles
heterozygous
having 2 different alleles
phenotype
the characteristic that is shown
co-dominant
both alleles contribute to the phenotype, so that both characteristics are present at the same time
which is dominant and which is recessive?
“brown eye” allele
“blue eye” allele
“brown eye” allele is dominant
“blue eye” allele is recessive
which is dominant and which is recessive?
“unnatached earlobe” allele
“attached earlobe” allele
“unnatached earlobe” allele is dominant
“attached earlobe” allele is recessive
which is dominant and which is recessive?
“non-tongue rolling” allele
“tongue rolling” allele
“tongue rolling” allele is dominant
“non-tongue rolling” allele is recessive
which two chromosomes do women give and which two do men give?
women = XX
men = XY
if one parent has the “brown eye” allele and one has the “blue eye” allele then what colour eyes will their offsrping have? why?
brown eyes
this is the dominant allele
is both parents have the attached ear lobe allele then what type of ears will their offspring have? why?
attached
although it is recessive it is the only allele available
if the father gives an X chromosome then what sex will the child be? why?
female (XX)
XX is the only available option as the mother also gives X
if the father gives a Y chromosome then what sex will the child be? why?
male (XY)
the mother gave an X and the father gave a Y
if a white feather allele chicken mates with a black feather allele chicken then what colour will their offspring be? why?
speckled (black and white)
co-domincance
if the mother gives a haemoglobin allele and the father gives a sickle haemoglocin allele then what will their offspring have? why?
normal and sickle red blood cells
co-dominance
which blood groups are co-dominant and which are recessive?
blood group A and B are co-dominant and blood group O is recessive
if the mother is blood group A and the father is group A then what blood group will their offspring be?
blood group A
if the mother is blood group B and the father is group B then what blood group will their offspring be?
blood group B
if the mother is blood group A and the father is group B then what blood group will their offspring be?
blood group AB
if the mother is blood group O and the father is group O then what blood group will their offspring be?
blood group O
if the mother is blood group O and the father is group B then what blood group will their offspring be?
blood group B
if the mother is blood group A and the father is group O then what blood group will their offspring be?
blood group A
complete this blood group chart
what is a punnett square?
a diagram showing a genetic cross
which allele is represent in lower case and which with upper case?
dominant = upper case
recessive = lower case
complete this punnett square
complete this punnett square
complete this punnett square
how do you set out a genetic cross?
QUESTION
probability is zero
both parents must be DD
dd parents are sterile
neither parent has d/ recessive allele
(ignore the term ‘gene’)
the symptoms of hungtington’s disease doesn’t appear until middle age (around 40)
suggest why this makes it unlikely that the disease will every disappear from the population
would already have children/ gene already passed on
didn’t know they were carriers of the disease
which part of the cell contains genetic information?
nucleus / chromosomes
name the molecule that genetic material is made from
DNA
a pregant woman asked her doctor about the chances of her baby being a boy
the doctor said there was an equal chance of the baby being a boy or girl
complete a genetic cross to explain why the doctor said this
what did Gregor Mendel discover about inheritance?
characteristics have a genetic ratio of 3:1
what is a Pedigree Tree?
a family tree that records and traces the occurence of a characteristic in a family
what is a mutation?
changes in the order of bases in the DNA
what is mutagen?
an agent that causes mutations
what is a genetic disease?
a condition or illness caused by mutations in genes or chromosomes
are all mutations changes in the proteins made?
no
there can be silent mutations
what is a chromosome mutation?
a change in the number of chromosomes
most mutations are …
some mutatins are …
very few mutations are …
most mutations are harmful
some mutatins are neutral
very few mutations are beneficial
what can mutations give rise to and what are some examples of this?
genetic diseases
e.g. albanis, cystic fibrosis, Huntington’s disease, Methemoglobinemia, sickle cell anaemia, achondroplasia, colour blindness, haemophilia
give some examples of causes of mutations
ionizing radiation - X ray, UV, gamma rays
chemicals - tabacco smoke
viruses
errors in mitosis and meisos
can dominant alleles be rare and recessive alleles be common?
yes
complete this genetic variation/mutations tree
complete this eye colour pedigree tree
complete this tongue rolling pedigree tree
