- Nuclear envelope form around each set of chromosomes, Each new nucleus is now __________, Sister chromatids no longer identical because of ___________.
- __________ are pulled to opposite poles of the cell, Microtubules are attached to the __________ at each pole of the cell.
- Microtubules of __________ shorten, __________ are separated from each other, __________ remain attached at centromeres.
- Nuclear envelope re-forms, 4 genetically _________ cells produced, Cytokinesis follows.
- Nuclear envelopes dissolve , Spindle apparatus forms, Microtubules attach to the __________ of each __________.
- _________ hold homologues together following crossing over, Microtubules attach to each __________, __________ align at the __________ plate side by side.
- Nuclear envelope ___________, Homologues closely associated in __________ (this word starts with an e), Crossing over occurs between __________ chromatids.
- Chromosomes align single file on the __________ plate, The sister chromatid are held together at the _________ with a protein called __________.
Anyone that can figure out the correct answers to the following problems will get a treat (yes, childish but who doesn't love candy?)
1.
A man and a woman living in a tropical area where
malaria is prevalent have 7 children. The genotypes of these children are ss,
Ss, SS, ss, Ss, Ss, and SS. (SS makes all normal hemoglobin, ss makes all
abnormal hemoglobin, Ss makes some of each kind of hemoglobin)
a.
What is the genotype of the parents?
b.
How many of their children would you expect to live to
adulthood and reproduce?
c.
What is their genotype?
2.
In dogs, there is an hereditary deafness caused by a
recessive gene, “d.” A kennel owner has a male dog that she wants to use for
breeding purposes if possible. The dog can hear, so the owner knows his
genotype is _________?. If the dog’s genotype is Dd, the
owner does not wish to use him for breeding so that the deafness gene will not
be passed on. This can be tested most efficiently by breeding the dog with what
genotype? Draw the Punnett squares to illustrate
these two possible crosses and you will see which cross is most efficient.
a.
What percentage of the offspring would be expected to
be hearing (in each case)?
b.
What percentage of the offspring would be expected to
be deaf (in each case)?
c.
How could you tell the genotype of this male dog?
d.
Using Punnett square(s), show how two hearing dogs
could produce deaf offspring.
3.
In humans, there is a gene that controls formation (or
lack thereof) of muscles in the tongue that allow people with those muscles to
roll their tongues, while people who lack those muscles cannot roll their
tongues. The ability to roll one’s tongue is dominant over non-rolling.
The ability to taste certain substances is also
genetically controlled. For example, there is a substance called
phenylthiocarbamate (PTC for short), which some people can taste (the dominant
trait), while others cannot (the recessive trait).
Let’s let R represent tongue-rolling, r
represent a non-roller, T represent ability to taste PTC, and t
represent non-tasting.
Suppose a woman who can roll her tongue and can not
taste PTC has children with a man that is a can roll his tongue and is a PTC
taster. 50% of their children are homozygous tongue-rollers and heterozygous
tasters, and 50% of their children are heterozygous tongue-rollers, and
homozygous non-tasters.
a.
What are the genotypes of the parents?
b.
What are the percentages of the phenotypes of the
children?
c.
If all their offspring marry non tongue rollers what
percentage of their grandchildren will be able to roll their tongues?
4.
Ms. Johnston, Ms. Johnson, and Ms. Johnstone all entered
the same hospital and gave birth to baby girls on the same day, and all three
babies were taken to the nursery to receive care, there. Someone later claimed
that the hospital mixed up the babies. As a hospital administrator, it is your
job to make sure that each pair of parents has the correct baby, so you order
blood typing to be done on all the parents and all the babies. Here are the
results:
Ms. Johnston – A
Mr. Johnston – B
Ms. Johnson – B
Mr. Johnson – O
Ms. Johnstone – A
Mr. Johnstone – A
Baby 1 – O
Baby 2 – AB
Baby 3 – B
a.
Which baby belongs to which parent?
b.
Who else could have been the parents of baby 1?
c.
Who else could have been the parents of baby 3?
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