BIOLOGY 1A03 Lecture Notes - Lecture 1: Chromosome Abnormality, Nondisjunction, Fundamental Theorem Of Arithmetic

63 views3 pages

indigojellyfish861

30 Mar 2016

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

doinhumolalala and 39849 others unlocked

BIOLOGY 1A03 Full Course Notes

Verified Note

9 documents

Document Summary

Failure of either of two homologous chromosomes to pass to separate cells during the irst meioic division. Or failure of the two chromaids of a chromosome to pass to separate cells during mitosis or during the second meioic division. When occurs in mitosis it can lead to cell lineages with extra or missing chromosomes (seen in cancer cells) One daughter cell receives an extra copy of one chromosomes and the other daughter cell receives no copy of that chromosome. Leads to aneuploidy (aneuploid cells have an abnormal number of chromosomes) Note: nondisjuncion can also occur in mitosis, but not afect the enire organism to great extent (may become apoptoic) or become cancerous. Brief period of mitoic divisions (all division is complete before birth) One egg released each month (others become atreic) Meiosis ii is completed only when the sperm is present. It"s esimated that 1/3 of all concepions abort. Approximately 1/4 of these occur prior to the detecion of pregnancy.

Related Questions

-Complete the following sentences: metaphase of mitosis, prophase II of meiosis, crossing over, anaphase I of meiosis, variable, random fertilization, identical, random orientation, metaphase I of meiosis, prophase I of meiosis, metaphase II of meiosis, reduction division

Two processes that occur during meiosis produce genetically ____________ cells.

In a process called ____________ , paired homologous chromosomes align randomly at the cell equator. This occurs during this stage of cell division: ____________ .

In a process called ____________ , genetic material is exchanged between homologous chromosomes. This occurs during this stage of cell division: ____________ .

-Complete the following paragraph to describe nondisjunction and the resulting effects on chromosome number.

words: euploidy, primary nondisjunction, nomal, nondisjunction, secondary nondisjunction, homologous chromosomes, abnormal, trisomy, monosomy, sister chromatids, aneuploid

1.During meiosis I, ____________ separate and move towards opposite ends of the poles.

2.During meiosis II, ____________ separate and move towards opposite ends of the poles.

3.During meiosis I, if both members of a homologous pair go into the same daughter cell, ____________ is said to occur and no normal gametes are produced.

4.During meiosis II, if the sister chromatids fail to separate and both daughter chromosomes go into the same gamete, ____________ is said to occur. Half the gametes are aneuploid while the other half are euploid.

5.If an egg that contains 24 chromosomes instead of 23 chromosomes is fertilized by a normal sperm, ____________ is said to have occurred.

6.If an egg that contains 22 chromosomes instead of 23 chromosomes is fertilized by a normal sperm, ____________ is said to have occurred.

6.A) If one follows 120 primary oocytes in an animal through their various stages of oogenesis, how many secondary oocytes would be formed?

B) How many first polar bodies would be formed?

C) How many ootids would be formed?

D) If one follows 120 primary spermatocytes in an animal through their various stages of spermatogenesis, how many secondary spermatocytes would be formed?

E) How many spermatids would be formed?

14. From which phase of the cell cycle does a cell enter G0 phase

21. Which of the following is true about the second meiotic division?

-The products are four identical gametes.

-Homologous chromosomes are pulling apart.

-Nondisjunction would lead to extra bivalents forming.

-Synapsis occurring in the second meiotic division.

-Sister chromatids are pulling apart.

23.Which if the following is true?

-Cells are 4n after S phase.

-Sister chromatids in mitosis are not identical.

-Cells are considered to be 2n after meiosis I.

-A chromosome always contains the same number of chromatids, regardless of phase of the mitotic or meiotic cell cycle.

-A chromosome may contain one or two chromatids in different phases of the mitotic or meiotic cell cycle.

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

BIOLOGY 1A03 Lecture Notes - Lecture 1: Chromosome Abnormality, Nondisjunction, Fundamental Theorem Of Arithmetic

BIOLOGY 1A03 Full Course Notes

Document Summary

Get access

Related Documents

BIOLOGY 1A03 Lecture Notes - Lecture 9: Spindle Checkpoint, Turner Syndrome, Zygote

BIOLOGY 1A03 Lecture Notes - Lecture 28: Chromosome Abnormality, Nondisjunction, Aneuploidy

BIOLOGY 1A03 Lecture Notes - Lecture 19: Sister Chromatids, Nondisjunction, Meiosis

Related Questions