Download Cellular basis of reproduction and inheritance packet B

Name _______________________________
Period ____________
Grades Nine Through Twelve
Biology/Life Sciences
Science Content Standards
Standards that all students are expected to achieve in the course of their studies.
Genetics
2. Mutation and sexual reproduction lead to genetic variation in a population. As a basis for
understanding this concept:
a. Students know meiosis is an early step in sexual reproduction in which the pairs of chromosomes
separate and segregate randomly during cell division to produce gametes containing one
chromosome of each type.
b. Students know only certain cells in a multicellular organism undergo meiosis.
c. Students know how random chromosome segregation explains the probability that a particular
allele will be in a gamete.
d. Students know new combinations of alleles may be generated in a zygote through the fusion of
male and female gametes (fertilization).
e. Students know why approximately half of an individual's DNA sequence comes from each parent.
f. Students know the role of chromosomes in determining an individual's sex.
Meiosis and Crossing Over
1.
somatic cells:
2.
In humans, a typical body cell has _______ chromosomes or ______ matched pairs.
3.
homologous chromosomes:
4.
locus of a gene:
5.
Explain the difference between autosomes and sex
chromosomes.
6.
gametes:
7.
diploid cell:
notation:
diploid number of a human body cell:
8.
haploid cell:
notation:
haploid number of a human egg or sperm cell ________
ETIMOLOGY
centro- or centri- = center (Latin)
-mere or –mer = part (Greek)
kinesis or kinetic = moving (Greek)
-chore= dance (Greek)
meta- = among or middle (Greek)
ana- = back (Greek)
telo- = goal (Greek)
inter- = between (Latin)
cyto- = cell (Greek)
-some = body (Greek)
homo-=same (Greek)
logo-=plan or logic (Greek)
diplo-=double (Greek)
haplo-=single (Greek)
-oid=form (Greek)
9.
In humans, a haploid sperm cell from the father fuses with a haploid egg cell of the mother in the
process of ________________________.
10. The resulting fertilized egg, called a _________________, is _______________.
Meiosis differs from mitosis in 3 important ways.
•
In meiosis, two nuclear divisions take place instead of one as in mitosis.
11. Result of Meiosis I:____________________________________________________
12. Result of Meiosis II:____________________________________________________
•
Four daughter cells result from these divisions, in contrast to the two daughter cells that
result from mitotic cell division.
•
Homologous chromosomes pair up side by side during the first meiotic division. This allows
for the exchange of corresponding pieces of DNA (crossing-over), thus distributing a random
mixture of maternal and paternal chromosomes to each gamete (egg or sperm cell).
13. Sketch the different stages of Meiosis and describe the important events.
Interphase
Sketch the cell
Prophase I
Meiosis I
Describe main events
Metaphase II
Prophase II
Meiosis II
Telophase I
& Cyokinesis
Anaphase I
Metaphase I
Anaphase II
Telophase II
& Cyokinesis
14. What is the end result of Meiosis I?
15. What is the end result of Meiosis II?
16. Complete the diagrams to display the formation of Egg Cells (Oogenesis) and Sperm cells
(Spermatogenesis). [Refer to pgs. 540-541 to assist you.]
2n = 4
Chromosomes shown after
Interphase and after DNA
replication
Sperm cells
Egg cell
Polar bodies
17. ootid:
18. polar bodies:
19. What is the difference between an ootid and polar bodies?
Independent orientation of chromosomes in meiosis and random fertilization lead to varied
offspring
20. Offspring that result from ______________ reproduction are highly varied; they are genetically
different from their parents and from one another.
21. Describe the independent orientation (independent assortment) of chromosomes
22. A particular species of toad has a diploid number of 20. How many chromosome combinations are
possible for gametes formed by meiosis? Show your work!
23. genes:
24. crossing over:
25. chiasma:
26. Describe, in words, the process of crossing over. Use a diagram to assist in your description.
27. genetic recombination:
28. genetic recombination results when:
1)
2)
3)
29. How does genetic recombination help a species survive?
30. During which phase of meiosis I do you think genetic recombination occurs besides during crossingover in prophase? How might genetic recombination occur in this stage?
What if something goes awry (wrong) in meiosis?
31. nondisjunction:
32. Draw what happens during a nondisjunction event during meiosis I.
2n = 4
meiosis I
meiosis II
gametes
33. Draw what happens during a nondisjunction event during meiosis II.
2n = 4
meiosis I
meiosis II
gametes
34. Suppose that in a certain plant with a haploid number of 12, DNA replication took place and the
chromatids in anaphase of meiosis II separated but that cytokinesis did not occur. How many
chromosomes would the zygote have if the resulting egg was fertilized by a normal sperm?
Chromosome alterations
35. deletion:
36. duplication:
37. inversion:
38. translocation: