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Flashcards in Chapter 9 Deck (42)
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1
Q

What do some types of Chemotherapy target?

A

Some types of chemotherapy target Mitosis

2
Q

What is Taxol? What does it treat? How?

A
  • From bark of Pacific Yew tree
  • Treats ovarian and breast cancer
  • It binds to microtubules, stabilizing them, the cell cannot divide after mitosis
  • Makes the cell unhealthy*
3
Q

What is Vinblastine?

A
  • From Madagascar Periwinkle

- These plants produce this so the animals don’t eat them cause of the negative effects

4
Q

How does Vinblastine work?

A

It binds to tubulin, stopping the formation of microtubules

- Cells cannot form spindle fibers needed to move the chromosomes

5
Q

What is Colchicine?

A
  • It treats gout (attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint.)
  • Stops the microtubules from forming, has very slow movement
6
Q

Are normal animal cells haploid or diploid?

A

Diploid (2n)

7
Q

When cells multiply by asexual means, the number of chromosomes is _________

A

kept at 2n

8
Q

Number of chromosomes in:
Humans?
Mosquitos?
Dogs?

A
Humans= 46 (2x23)
Mosquitos= 6 (2x3)
Dogs= 78 (2x39)
9
Q

Do the life cycles of diploid organisms require a haploid phase?

A

Yes it is called meiosis

10
Q

In animal life cycles, a mechanism is required to reduce the number of chromosomes in half so that what?

A

So that following fertilization, the number of chromosomes returns to the original level

11
Q

Meiosis

A

The process of producing haploid (1n) cells for sexual reproduction
- It keeps the # of cells constant from generation to generation

12
Q

Homologous chromosomes

Also called what?

A

Contain different versions of the same information

  • A pair of chromosomes
  • Also called a Tetrad
13
Q

What are duplicated chromosomes also called?

A

Sister chromatids

14
Q

What does Meiosis consist of? What is the result?

A

Meiosis consists of one replication of the cellular DNA, but has 2 cell divisions
- This leads to the production of 4 haploid cells rather than 2 diploid cells

15
Q

In prophase I:
What happens during the Synapsis?
What happens during Recombination?

A
Synapsis = homologous chromosomes line up- 4 chromatids are stuck together
Recombination = Crossing over occurs between the pairs
16
Q

How long does Meiosis take in human sperm cells?

A

It can take up to a month, with Prophase I taking up to a week alone

17
Q

In human egg cells, Prophase I begins during ___________, and Meiosis is completed _______________

A

In human egg cells, Prophase I begins during fetal development, and Meiosis is completed just prior to egg release

18
Q

What is the process of Crossing over? Is there a benefit?

A

In synapsis, the homologous DNA segments can interact and in some cases pieces of DNA can be swapped from one chromatid to another
- Benefit is that it increases variation

19
Q

Chiasma

A

The point where two homologous non-sister chromatids exchange genetic material during chromosomal crossover during meiosis

20
Q

What are the 5 steps to crossing over?

A

1) Homologous chromosomes condense
2) Synapsis begins(protein between chromosomes)
3) Bivalents form (protein connects chromosomes)
4) Crossing over occurs
5) Chiasma becomes visible as chromosome arms separate during late prophase

21
Q

What is the benefit of crossing over?

A

It increases genetic variability of offsprings, and can lead to new phenotype combinations

22
Q

In which phase do the tetrads line up together at the cell equator and then the chromosome pairs separate?

A

Metaphase I

23
Q

In which phase do the sister chromatids stay together as the pairs are separated?

A

Anaphase I

24
Q

Interkinesis

A
  • After cytokinesis I
  • No DNA replication between the 1st & 2nd meiotic division
  • does not go back to an interphase stage
25
Q

What are the cells like after Cytokinesis I?

A
  • Cells are haploid, with duplicated chromosomes

- and they are now separated in Meiosis II

26
Q

What is the result of Meiosis II?

A

Once the process is complete, it will give 4 haploid cells

- each with n chromosomes

27
Q

In humans, with our 23 pairs of chromosomes, what does independent assortment mean?

A

That there are many different possible genetic outcomes

- 2^23 (8.3 million) = does not count for crossing over!!

28
Q

What explains why you do not look exactly like your siblings?

A

Due to independent assortment

- And because there are so many different possible genetic outcomes

29
Q
Mitosis vs Meiosis:
# of chromosomal duplications?
# of cell divisions?
# of daughter cells produced?
# of chromosomes in daughter cells?
A

Mitosis vs Meiosis:

1: 1
1: 2
2: 4
2n: 1n

30
Q

Mitosis vs Meiosis:
How chromosomes line up in metaphase?
Genetic relationship of daughter to parent cells?
Functions performed in the human body?

A

Mitosis vs Meiosis:
singly: tetrads then singly
Identical: Unique
Growth development repair: production of gametes

31
Q

What is a type of problem that could occur in meiosis?

A

Nondisjunction in meiosis:
The homologous pair of chromosomes fail to separate at Anaphase I or II, therefore the resulting gametes will be:
n+1, n+1, n-1, n-1 instead of n, n, n, n

32
Q

Which disease can nondisjunction lead to?

A

It can lead to Down syndrome - when there are 3 copies of the chromosome #21

33
Q

What type of chromosomes do a normal fruit fly have?

A

Diploid; 2n (2 sets)

34
Q

What type of chromosomes do polyploid fruit flies have?

A

Triploid; 3n (3 sets) OR

Tetraploid; 4n (4 sets)

35
Q

Translocation

A

Translocation can occur when sections of chromosomes stick together and do not divide properly
- It is between different chromosomes, with different genes EX. pink& purple ones

36
Q

Is any DNA lost in a balanced translocation?

A

No, however if the break occurs in a gene problems can still result… It can also pose problems for subsequent generations

37
Q

however, when a cell that contains a translocation undergoes meiosis, the information that gets passed on to the next generation ________

A

May not be complete

38
Q

Chromosomes:

Duplication

A

Effect: Doubles a particular region

39
Q

Chromosomes:

Deficiency (deletion)

A

Effect: Removes a segment of chromosome

40
Q

Chromosomes:

Inversion

A

Effect: Flips a region to the opposite orientation

41
Q

How is meiosis different from mitosis?

A
  • Mitosis = diploid; Meiosis = haploid

- Genetic variation = resulting cells are different

42
Q

Are the changes of chromosomes during meiosis good or bad?

A

Individually = more often bad

Long term = lead to good things, more complex organism