Day 32, returning to genetics, Chapter 13, pp. 234 -- 235

 We're going to take this piece by piece.

First, review the chart on mitosis.  Remember that mitosis is when cells replicate into exact copies for growth and repair.  When your skin cells make more skin cells to replace the ones that die and fall off, or when fetal liver cells make more liver cells as the liver gets bigger, that sort of thing.  

Now we move to reproduction, where an organism (or two organisms) make new organisms.  This might be asexual, just one organism making a new organism that will be the same as itself (but with variation, it gets complex) or it might be sexual, where two organisms contribute genetic material to the new organism to make a unique DNA code for a unique new individual.

Nice, straightforward video (2 minutes)

What is a gene (5 minutes)

Quick preview about genes (2 minutes)

examples of asexual reproduction (8 minutes)

more on asexual reproduction (6 minutes)

what is a chromosome (6 minutes)

Quiz:

Match the term with the definition:

1.  DNA                                       

2.  gene                           

3.  chromosome

4.  chromatid

a.  a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

b.  deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

c.  (in technical use) a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.

d.  each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.

5.  Write a short paragraph describing asexual reproduction.