Mitosis & Meiosis Cloning & Cancer Mendellian Genetics DNA Structure Potpourri

How many autosomes would you find in each autosomal cell?

44

What is another names for meiosis I? Why is the name appropriate?

Reduction Division

What are homologous chromosomes?

Homologous chromosomes are similar but not identical (like a pair of shoes) and each one has come from each of your parents.

How does triploidy differ from trisomy?

trisomy triploidy. If a gamete with an extra chromosome is fertilized by a normal gamete all the cells that develop from the zygote will also have an extra chromosome = trisomy If a diploid, rather then haploid, gamete unites with a normal gamete the resulting zygote will have three sets of chromosomes (3n) and this is referred to as triploidy.

Outline the major steps in meiosis and mitosis indicating how the two are different.

Mr. Leeder’s Discretion

What is another term for cloning? It is a form of reproduction.

Asexual Reproduction

What is genetic engineering?

Intentional production of new genetic material by substituting or altering existing material.

What does enucleated mean? Why is this important to the process of cloning?

What is metastasis?

When a cancer cell breaks free from the tumour and moves into another tissue.

What is cancer? In your answer include what can cause cancer.

Cancer cells divide uncontrollably on their own. Cancer cells can divide in culture about once every 24 hours. Not in living organisms though (thankfully!!!) Cancer cells lack the ability to mature and specialize: Therefore another threat is that cancer cells cannot carry out some of the functions of normal cells. Genetics plays a relatively small role in predicting cancer (breast cancer is one of the few cases where there is documented evidence) Lifestyle!!!

What is the first law of heredity? Also known as the law of segregation.

Inherited traits are determined by pairs of alleles from each parent. These alleles separate during gamete formation giving each offspring only one allele from each parent

Examine the following pedigree Is the trait dominant or recessive? Is it sex linked or autosomal? How do you know?

Recessive and Autosomal

When would a test cross be completed? Provide an example if possible

Unknown crossed with a homozygous recessive If any black sheep born, you know the ram was heterozygous

How are co-dominance, incomplete dominance and multiple alleles different?

Multiple Alleles – many genes have more than two alleles and this occurs in human blood typing and the glycoproteins that are present on red blood cells. Incomplete Dominance – a blending whereby the heterozygote exhibits an intermediate phenotype between two homologous phenotypes. Co-dominance – when both alleles for a trait are equally dominant.

What is the second law of heredity? Also known as the law of independent assortment.

Inheritance of alleles for one trait does not affect the inheritance of alleles for another trait

Why is cytology closely related to genetics?

An understanding of cells allowed for a better understanding of what is going on inside in terms of genetic information

What did Tomas Morgan discover? Can you provide a Punnett square example?

Some traits that are passed on depend on the sex of the parent carrying the trait. Transmission of genes that are located on one of the sex chromosomes, X or Y

How did Hershey and Chase discover DNA was the genetic material?

Worked with bacteriophages Viruses that attack bacteria and use the bacteria’s structures to quickly reproduce new viruses in the cell Outer coating made of protein and inside carries DNA 35 S on protein and 32 P on DNA DNA went inside the cell, therein this is what was being transmitted therein it must be the genetic information.

What role did Watson and Crick play in determining the structure of DNA?

Double Helix Complementary Base Pairs Franklin?

What is recombinant DNA and why is it useful?

What are autotrophs?

What is the haploid number for humans?

23

What is a Barr body?

Females have two copies of the X chromosome however the amount of proteins in males and females is equal. What happens is that one of the X chromosomes is inactivated randomly, it is referred to as a Barr body. It is important to remember that different X chromosomes are inactivated in different cells.

What is a karyotype?

Illustration or photograph of the chromosomes in the nucleus of a somatic cell in an organism 46 chromosomes paired according to size, shape and appearance.

Identify and explain the two major processes that contribute to genetic variation.

Crossing over – occurs during prophase I and the number of which is determined by the chromosome size (usually 2 or 3 cross overs per chromosome). Random Segregation – how each pair of homologous chromosomes line up during metaphase I is also extremely important as that determines which pole the chromosomes will go to.

How do we know that our genetic code is read in groups of 3 nitrogenous bases known as a codon?

If each nucleotide coded for one amino acid, we would only need 4 amino acids If two nucleotides coded for one amino acid, we still would not have enough combinations. So we have three nitrogenous bases to code for one amino acid (although there are now 64 different combinations). However, in some cases two or more codons code for the same amino acid