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BIOL 1201 Chapter : 02-Jul-13

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azuremammoth471
15 Mar 2019
School
LSU
Department
Biological Sciences
Course
BIOL 1201
Professor
All

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Document Summary

Like mitosis, meiosis is preceded by the replication of chromosomes. Meiosis takes place in two sets of cell divisions, called meiosis i and meiosis ii. The two cell divisions result in four daughter cells, rather than the two daughter cells in mitosis each daughter cell has only half as many chromosomes as the parent cell. *if a gamete is haploid and goes through replication it stays haploid. In the first cell division (meiosis i), homologous chromosomes separate. Meiosis i results in two haploid daughter cells with replicated chromosomes; its is called reductional division. In the second cell division (meiosis ii), sister chromatids separate. Meiosis ii results in four haploid daughter cells with unreplicated chromosomes; it is called the equational division. Meiosis i is preceded by interphase, in which chromosomes are replicated to form sister chromatids. The sister chromatids are genetically identical and joined at the centromere. Prophase i typically occupies more than 90% of the time required for meiosis.

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Related Questions

1). If the diploid chromosome number of an organism is 2N=12, how many chromosomes will be found in this organism's sperm?

a). 6 replicated chromosomes
b). 12 replicated chromosomes
c). 6 unreplicated chromosomes
d). 12 unreplicated chromosomes

2). When do homologous chromosomes segregate into two different daughter cells?

a). fertilization
b). meiosis I
c). mitosis
d). meiosis II

3). When do sister chromatids segregate into two different daughter cells? (Choose ALL correct answers)

[] mitosis
[] fertilization
[] meiosis I
[] meiosis II

4). When does crossing over (the formation of chiasmata) occur?

a). meiosis I
b). meiosis II
c). mitosis
d). fertilization

Determine whether the following applies to mitosis, meiosis, orboth; also identify the specific stage of cell division thatapplies (e.g. mitosis prophase, meiosis anaphase II, etc)



1) chromosomes pairs line up across the center of the cell


2) sister chromatids seperate


3) spindle fibers separate homologous chromosomes


4) 4 haploid daughter cells are produced


5) a cell 1st undergoes DNA replication


6) chromosomes line up single file across the middle of thecell


7) sister chromatids separate from each other


8) 2 haploid daughter cells form


9) the nuclear membrane re forms


10) spindle fibers attach to pairs of homologous chromosomes


11) the nuclear membrane begins to dissolve


12) centrosomes duplicate


13) synapsis and crossing over occurs


14) 2 diploid daughter cells form

M2A1 Worksheet: Mitosis and Meiosis

A dog is a diploid organisms and has 39 pairs of chromosomes (2n = 78), where n = 39 chromosomes from each parent. Use this example to answer the following question regarding chromosomal number.

INTERPHASE

How many chromosomes are present in the somatic cell?

What do they look like?

What are they “doing” in G1 of this phase?

What is happening in the S phase?

What is happening in the G2 phase?

What follows G2 phase in a somatic cell?

What follows G2 phase in a gamete cell?

MITOSIS

Number of chromosomes in the parent cell.

Number of chromatids in the parent cell.

Number of chromosomes in the daughter cell.

Number of chromatids in the daughter cell.

How many daughter cells are produced?

Are the daughter cells haploid or diploid?

How many cell divisions take place?

In what type of cell does this division occur?

Meiosis 1:

Number of chromosomes in the parent cell.

Number of chromatids in the parent cell.

Number of chromosomes in each Meiosis I daughter cell.

Number of chromatids in each Meiosis I daughter cell.

Are the daughter cells haploid or diploid at the end of Meiosis 1?

Meiosis II:

Number of chromosomes in the “parent” cell (which is a daughter cell from Meiosis I).

Number of chromatids in the “parent” cell.

Number of chromosomes in each Meiosis II daughter cell.

Number of chromatids in each Meiosis II daughter cell.

Are the daughter cells haploid or diploid at the end of Meiosis II?

Which phase or phases of Meiosis account for the genetic variability among the daughter cells? How… what happens in this phase to create the diversity?

Comparing Mitosis and Meiosis…..

How many daughter cells result from Mitosis? Are they diploid or haploid?

How many daughter cells result from Meiosis? Are they diploid or Haploid?

Cell structures and function: Match each organelle to its function:

Organelle Function

Lysosome 1. Lipid synthesis

Rough ER 2. Houses DNA

Nucleus 3. Energy extraction

Smooth ER 4. Dismantles debris

Golgi apparatus 5. detoxification

Mitochondria 6. Protein synthesis

Peroxisome 7. Processes secretions

What is the function of checkpoint proteins in the cell cycle?

How can all of a person’s cells contain exactly the same genetic material, yet specialize as bone cells, nerve cells, muscle cells and connective tissues?

What are the 3 primary germ layers?

Briefly, in one or two sentences, distinguish between

a bacterial cell and a eukaryotic cell

interphase and mitosis

mitosis and apoptosis

an autosome and a sex chromosome

homologous pair of chromosomes and a sister chromatid

centromere and centriole

chromosome and chromatid

monozygotic and dizygotic twins

allele and gene