Chapter 8Lecture Introduction to reproduction at the cellular level

Question 1

Cell Cycle Stages:

What are the major events of each stage?

Answer 1

Gap 1 (G1)- Growth, prepare, rest cell cycle
Synthesis- DNA is replicated
Gap 2 (G2)- Prepare to divide

Question 2

What are the major events of each stage? Propahse

Answer 2

Prophase-Nuclear envelope begins to degrade
. Endoplasmic reticulum and golgi appratus move to cell eddges
. Centrosomes move to poles
.sister chromatids begin to condense
Basically breaking down muclear envelope

Question 3

Metaphase

Answer 3

. Chromosomes are still completly codensed
. mitotic spindle helps align the chromosomes on metaphase plate in the center of cell
basically chromosomes move to the center of the cell

Question 4

Major stage of Prometaphase?

Answer 4

Prometaphase:
. Nuclear envelope completly degrades
. Mitotic spindle stretch length of cell
.Chromosome are completly condensed
. Microtubles attach to the kinetochore of each sister chromatid
Basically centrosomes move toward opposite poles or pack up move around and unpack the cell.

Question 5

Major event of Anaphase?

Answer 5

Anaphase:
. Kinetochore proteins and the spindle fibers pull the sister chromatids apart
. Single chromosomes pulled toward each poll
. All chromosomes sepaerated at the same time
. Cell elongates as it prepares for cytokinesis
Basically seperated of the sister chromatids

Question 6

Major even of telophase?

Answer 6

Telophase:
. Chromosomes begin to unrevel at each pole of the cell
. 2 nuclei begin to form aorunf each group of chromosomes
. Mitotic spindles break down
Basically rebuilt the nucleus and breaks down the mitotic spindle

Question 7

Stages of Meiosis: Major event of Prophase l:

Answer 7

Prophase l: Nuclear envelope breaking down, homlogous chromosomes vind firmly together

Question 8

Stage of Meiosis: Major event of Metaphase l:

Answer 8

Metaphase l : Homologous chromosomes randomly assemble at the metaphase and lined up

Question 9

Stage of Meiosis: major event of Anaphase l :

Answer 9

Anaphase l : spindle microtublese pull the homologous chromosmes apart seperate pair

Question 10

Stages of meiosis: Major events of Telophase l :

Answer 10

Telophase l : reverse broke envelope and bring it back up the envelop

Question 11

Stages of Meiosis: Major event of prophase ll :

Answer 11

Prophase ll : sister chromatids condense, nuclear envelope dissolves, centersomes move to each poles.

Question 12

Stages of Meiosis: Major event of Metaphase ll :

Answer 12

Metaphase ll : sister chromatids line up at metaphase plate

Question 13

stages of Meiosis: Major event of Anaphase ll :

Answer 13

Anaphase ll : sister chromatids pull apart by shortening of kinetochore microtubles.

Question 14

Stages of Meiosis: Major event of Telophase ll :

Answer 14

Telophase ll : Chromosomes arrive at the pole of the cell and decondense. reverse

Question 15

What form does DNA exist in during the different cell cycle stages?

Answer 15

chromatin.

Question 16

What is a homologous pair of chromosomes vs. a set of chromosomes?

Answer 16

Homologous chromosomes are chromosomes of same length with same length with same type of genes on locis which is a 2 sets of homlogous chromosomes 2 each

vs

Set of chrosomes: In humans, each set of chromosome is made of 23 chromosomes (22 autosomes and 1 sex chromosome). Pair of chromosome.

Question 17

How many chromosome pairs are in a typical diploid human cell? How many in a haploid human cell?

Answer 17

46 pairs in the diploid human cells

Haploid is 23 human cells

Question 18

What are the stages and sub-stages of the cell cycle, in order? During what stage is DNA replicated?

Answer 18

Gap 1 (G1), synthesis (S), Gap 2 (G2), and mitosis (M),
DuringMitosis,DNA is replicated during theS phase(Synthesis phase) ofInterphase.

Question 19

What is the G0 stage? What types of cells enter this stage?

Answer 19

G0 Stage is resting stage for cells that will not replicate/ divide
Cells never complete mitosis and will remain go forever like nerve cells

Question 20

How is cytokinesis in plant cells different from animal cells? Why?

Answer 20

Animal plants: forming a cleavage furrow.
Plant cell: cell wall forms

Question 21

How do prokaryotic cells divide?

Answer 21

Binary fission by :

-Cell growth, DNA replication
-Chromosomes attach to plasma membrane
- Cell elongates as chromosomes move to pole
- Septum forms during cytokinesis
- Septum completes forming 2 independent cells

Question 22

What checkpoints are in place to prevent uncontrolled cell division? What does the cell check for at these points?

Answer 22

1) Near the end G1
- Check for damage to DNA, protein quality, cell size, growth factors
2) At G2 to Mitosis tranition
- Check cell size, protein quality, and its DNA is poperly replicated
3) In Metaphase of mitosis
- Check to see if all sister chromatids are attach to microtubles.
Both direction oppsoite= Seperation
If nor seperated= Fewer or more chromotids= death/cancer

Question 23

What are some characteristics of cancer cells that make them unique from healthy cells?

Answer 23

They grow, divide and die. Cancer cells, on the other hand, don’t follow this cycle. Instead of dying, they multiply out of control and continue to reproduce other abnormal cells.

Question 24

What is the difference between a benign and malignant tumor?

Answer 24

Benign remains in one site
Malignent tumor includes cells that can spread to other parts of the body via the blood or lymph system

Question 25

How do cancer cells spread from one location in the body to another?

Answer 25

By malignant tumor inclues cells that can spread to other parts of the body via the blood or lymp sytem called metastasis

Question 26

What is the purpose of cell division via mitosis?

Answer 26

 The major purpose of mitosis is for growth and to replace worn out cells.

Question 27

How do crossing over and independent assortment affect diversity?  When do they occur in meiosis?

Answer 27

 creates sets of chromosomes with new combinations of alleles. Occur in Prophase 1 and Metphase 1

Question 28

What is Down syndrome?  What is it caused by?

Answer 28

Down syndrome is usually caused by an error in cell division called “nondisjunction.” Down syndrome is a genetic disorder caused when abnormal cell division results in extra genetic material from chromosome 21.

Question 29

What is a karyotype used for?  What information can it provide?

Answer 29

Karyote is used for number and visual of chromosomes in a cell information it provides is help idetify gentic problems as the cause and number of disorders and disease.

Question 30

What is nondisjunction, and what is the result of nondisjunction?

Answer 30

Nondisjunction is chromosomes do not seperate poperly in meiosis. The result is all gamestes abnormal with result of gametes with more or less than 23 chromosomes

Question 31

What does it mean to be polyploid?

Answer 31

More than the correct number if chromosomes pairs ex: 2n Diploid 3n, 4n, 6n

Question 32

Be able to recognize examples of inversions, translocations, insertions, and deletions.

Answer 32

Inverions is piece of chromosome is inverted (rotated 180 degrees) Translocation- Nonhomologous chromosomes exchange different genes Delations: Chromosomes portion is removed Insertions is inserted involves additon

Question 33

What are the advantages and disadvantages of asexual vs. sexual reproduction?

Answer 33

Asexual adavantage: Fast time mnagement, no need for meiosis or energy. Disadvantge Identical offspring, muti cellular organisms , single cell organism Sexual reproduction: Unique offspring, surive better in a changing enviorment Disadvantages: Requires two reproductive cells to occur between fertilization, slow