BIOL 118 Lecture Notes - Lecture 20: Sister Chromatids, Homologous Chromosome, Synaptonemal Complex

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amethystserval28

17 Mar 2017

School

Binghamton University

Department

Biology

Course

BIOL 118

Professor

Dennis Mc Gee, Steven Tammariello

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Document Summary

Interphase (figure 13. 7: chromosomes replicate, chromosomes are uncondensed, centrosomes replicate, now each chromosome consists of two identical sister chromatids attached at the centromere (figure 13. 3) Just like in mitosis: these are a homologous pair of chromosomes. See table 13. 1 for terms: meiosis i, purpose: to separate the homologous chromosomes into daughter cells, daughter cells are haploid, early prophase i (figure 13. 7, chromosomes condense, nuclear envelope breaks up, spindle apparatus forms. Synapsis occurs: homologous chromosome pairs come together, pairing called a bivalent, 2 of the homologs. Sister chromatids (two red: non sister chromatids (one red and one blue) Synapse: bivalent forms, chromosomes held together by proteins called the synaptonemal complex, crossing over, chromosomes break, but remain connected at chiasma. Independent assortment of paired homologues in anaphase i: result in 4 daughter cells whose chromosome composition is different from that of the parent cell.

Related Questions

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

turquoiseporpoise808

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 âdoingâ 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 âparentâ cell (which is a daughter cell from Meiosis I).

Number of chromatids in the âparentâ 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? Howâ¦ what happens in this phase to create the diversity?

Comparing Mitosis and Meiosisâ¦..

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 personâs 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

1) A tissue in a mouse contains two types of cells: one that divides rapidly and one that divides more slowly. The most likely difference between these two cell types is that the slow-dividing cell type spends more time in phase