Transcript Answers to 14.1 Genetics questions

14.1: Human Chromosomes:
1. What is a genome?
2. What is a karyotype and what can it show you?
How many pairs of chromosomes in a human?
3. Why do your chromosomes come in pairs?
Which numbered pair determines our gender?
What are the female sex chromosomes?
Male?
4. All human egg cells have what sex
chromosome? What about human sperm
cells? Which cell, then, determines the sex of
the next offspring? What are the chances of
having a boy or a girl for each pregnancy?
1. The full set of genetic information
in an organism’s DNA
2. Photograph of all chromosomes
in a body cell. Abnormalities in
chromosome number or shape.
23 pairs in human
3. One of each pair from ea. parent.
23rd pr. male=XY female=XX
4. eggs have X. sperm have X
OR Y. sperm cell determines
X
X
gender. 50/50
X
XX
Y XY
5. How many genes are on the X chromosome?
The Y chromosome? Name three genetic
5. 1200 genes on X.
conditions linked to the X chromosome.
Y has 140 genes. Color
blindness, hemophilia,
6. The most important gene on the Y chromosomemuscular dystrophy
which determines
“male6. Testis-determining factor
ness” is the __?
XX
XY
7. chromosome #1-22. 22 pairs. 44 total
7. What is an autosome? How
many pairs are there in a
human body cell? How
many autosomes total in a
human body cell?
8. What traits does the MC1R
gene code for? What will
recessive alleles of this
gene show? What will
dominant alleles show?
9. What is the Rhesus factor?
How does it help determine
blood type?
10. What is co-dominance and
give an example
8. hair and eye color. recessive = red
and blonde. dominant = darker hair
9. another protein on cell
membrane of RBC’s. Dominant
trait. Letter and Rh factor
10. Two dominant alleles. AB blood type
11. Describe the genes of
someone with AB- blood
type.
12. How many alleles are
involved in human blood
type?
11. His blood cell membranes have the A protein
and the B protein but lack the Rh protein. Can this
person get a transfusion of AB+ blood? why/why
not?
12. 3
13. On what chromosome are
sex-linked genes located?
Give an example
13. X chromosome. Red-green
colorblindness, hemophilia, muscular
dystrophy. Sex-linked genotypes and
crosses…..
14. What gender shows sexlinked traits more often
and why is that?
14. Males show sex-linked traits
more frequently. They only have one
X. If there is an abnormal, recessive
allele on their one and only X, they
will show that condition.
15. What question did British
geneticist Mary Lyon
answer about the X
chromosome? What did
she find out?
16. How do you explain this
phenomenon in a calico
cat?
17. What is a Barr body?
15. If one X was good enough for males,
how do females adjust to having two? One
X chromosome is highly coiled into a Barr
body…all the genes are switched off,
leaving only 1 X chromosome active
16. Gene for coat color spots is on the X.
Those cells whose active X has allele for
black fur will have black spots. Other
cells whose active X has orange coat
color, will have orange spots.
18. we’d have a mosaic
18. If the genes for human
of different colored skin
skin color were located on
patches
the X chromosome (and
thank God they are not),
what would that mean for
the appearance of the
human female?
19. Male calico’s
have spots of only
19. How can you tell a female one color (orange or
calico cat from a male
black) Females
calico cat by the coat
have patches of
appearance?
both colors
20. What is a pedigree, and
what do the following
symbols indicate:
circle, square, horizontal
line, vertical line, shaded
symbol, white symbol?
21. What does a pedigree
show you?
In figure 14-7, the
pedigree shows the
dominant trait of a white
hair flock in humans.
22. What is the genotype of
anyone with a “white”
symbol on the chart?
23. How is it possible to
apply Mendel’s principles
of genetics through
pedigree analysis?
20. a genetic family tree. circle = female, square =
male, horizontal line = marriage, vertical line =
offspring, shaded = trait seen, white = trait not seen
1
3
8
2
5
4
9
7
6
10
11
12
21. inheritance pattern of a particular trait
22. homozygous recessive (ww) What is the
genotype of 2? 3? 4? 6? 11? 12? Do we know
genotype of #8?
23. Pedigree info helps to determine the
nature of genes and alleles with associated
traits. You can see if the trait is dominant,
recessive or sex-linked