Today’s Lecture Summary:Today’s Lecture Summary:

Cellular reproductionCellular reproduction

• Binary fissionBinary fission

• MitosisMitosis

• MeiosisMeiosis

Reading Assignment: Chapter 8Reading Assignment: Chapter 8

Learning Outcomes:By the end of today’s lecture, you should be able to:- explain the difference between binary fission, mitosis and meiosis- list and describe the steps of mitosis and meiosis- list the processes by which cell division is regulated and explain what happens to cells that don’t respond to these regulatory mechanisms- explain the processes that lead to genetic variation during meiosis- explain the chromosomal problems that can occur during meiosis

Cell division:

Cell division functions:

- Growth & development

- Tissue renewal

- Reproduction

Binary fission occurs in prokaryotic cells:

Binary fission:

Human karyotype: ordered display of an individual’s chromosomes

Female karyotype:Female karyotype: Male karyotype:Male karyotype:

Genes: nucleotide sequences of DNA.

The location of the gene on the The location of the gene on the chromosome is called the chromosome is called the locus locus ((plural:plural: loci) loci). .

Different forms of a gene are called Different forms of a gene are called allelesalleles. .

Homologous chromosomesHomologous chromosomes are the same in are the same in size, shape and genetic information.size, shape and genetic information.

Mitosis:

Mitosis (cont.):

Mitosis in Animal Cell (LM):

Mitosis in Plant Cell:

Normal cells vs.

Cancer cells:

Cancerous breast tumor:

The asexual reproduction of a hydra:

Each couple has one daughter and one son. Which child belongs to which couple?

couple 2 couple 1 couple 1 couple 2

Meiosis:Meiosis: sexual sexual reproductionreproduction

Meiosis occurs Meiosis occurs in two phases:in two phases:

Meiosis I:Meiosis I:

Meiosis II:Meiosis II:

A cell with two A cell with two copies of a copies of a chromosome is chromosome is diploid (2N)diploid (2N)..

A cell with one A cell with one copy of a copy of a chromosome is chromosome is haploid (N).haploid (N).

Independent assortment during meiosis:

Crossing over during meiosis:

Down karyotype (Trisomy 21):

Down syndrome:

Alteration of chromosome number due to non-disjunction during meiosis I:

Non-disjunction during meiosis II:

Fertilization after non-disjunction:

Abnormal numbers of sex chromosomes:

Klinefelter syndrome (XXY): Turner syndrome (XO):

Alterations of chromosome structure:

Alterations of chromosome structure (cont.):

Translocation associated with chronic myelogenous leukemia (CML):

Today’s Lecture Summary:Today’s Lecture Summary:

Cellular reproductionCellular reproduction

• Binary fissionBinary fission

• MitosisMitosis

• MeiosisMeiosis

Reading Assignment: Chapter 8Reading Assignment: Chapter 8

Check for understanding…

1. Starting w/ a single cell, a series of 5 mitosis events would yield a total of how many cells?

2. A chemical prevents the production of DNA; what step in mitosis would be prevented?

3. a) A cell w/ 46 chromosomes undergoes mitosis to produce daughter cells w/ _____ chromosomes

b) A cell w/ 46 chromosomes undergoes meiosis to produce daughter cells w/ _____ chromosomes

4. How is reciprocal translocation different from normal crossing over?

Complete the table below: