Question | Answer |
1. List the three reasons cells must replicate/divide. | To replace, grow, and repair |
2. Describe the structure of a chromosome. What is a chromosome made of? | The DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. |
3. Describe the relationship between DNA, genes, and chromosomes. Part 1 | Genes are a segment of DNA. Our genes are the blueprint for our biology. They contain the instructions for things like the shape of our nose and the size of our feet. |
3. Describe the relationship between DNA, genes, and chromosomes. Part 2 | We can use the analogy of a city to better understand the relationship between DNA molecules, genes and chromosomes. One DNA molecule (one DNA 'letter' - A, T, G or C) would be represented by one house on a street. |
3. Describe the relationship between DNA, genes, and chromosomes. Part 3 | A gene would equal a whole street of houses. A chromosome is all the streets in a neighborhood. A set of chromosomes (for example all of the human chromosomes) would be represented by a city made up of all different neighborhoods. |
4. Describe the difference between sex cells and body/somatic cells. Part 1 | Sex cells are specialized cells called gametes. There are two types of gametes involved in sexual reproduction, sperm, produced by the testes in males, and ova, or ovum, produced in the ovaries of females. |
4. Describe the difference between sex cells and body/somatic cells. Part 2 | The basic difference between the chromosome count of gametes and somatic cells is that the gametes have what is referred to as a haploid number (n) of chromosomes, while the somatic cells have a diploid number (2n). |
4. Describe the difference between sex cells and body/somatic cells. Part 3 | Haploid means the normal chromosome count is divided by one half, while diploid would be the full count of chromosomes. In humans, the diploid count is 46 chromosomes, while the haploid count is half of that, or 23 chromosomes. |
4. Describe the difference between sex cells and body/somatic cells. Part 4 | An ovum with 23 chromosomes is fertilized by a sperm that also has 23 chromosomes. This "half-count" is very important, as 23 plus 23 will equal 46 chromosomes for a fertilized ovum, now called a zygote. |
5. Describe the difference between autosomes and sex chromosomes. | autosomes are the first twenty-two pairs of chromosomes and sex chromosomes are the twenty-third pair. (They decide the gender of the offspring) XY=male XX=female |
6. Describe the difference between male and female sex cells. | male sex cells or sperm cells, are relatively motile. Female sex cells, called ova or eggs, are non-motile and much larger in comparison to the male gamete. |
7. Describe the difference between male and female sex chromosomes. | Female has the sex chromosomes XX, the male has the sex chromosomes XY |
8. List the number of sex chromosomes and autosomes in body/somatic cells. | There are 2 sex chromosomes and 44 autosomes in a somatic cell |
9. List the number of sex chromosomes and non-sex chromosomes autosomes in sex cells. | There is 1 sex chromosome and 22 autosomes in a sex cell (gamete also known as egg or sperm) |
10. Define epigenetics and explain how epigenetic effects could cause cancer. | the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. Cancer is caused by failure of checks and balances that control cell numbers in response to the needs of the whole organism. |
11. Define cancer as a disease, describe how it is diagnosed, and describe three ways it can be treated. Part 1 | Cancer is a malignant tumor involving abnormal cell growth with the potential to invade or spread to other parts of the body. Not all tumors are cancerous; benign tumors do not spread to other parts of the body. |
11. Define cancer as a disease, describe how it is diagnosed, and describe three ways it can be treated. Part 2 | Cancer is nearly always diagnosed by an expert who has looked at cell or tissue samples (biopsy) under a microscope, blood tests can also help in diagnosing cancer.
Radiation therapy, chemotherapy, and surgery |
12. Distinguish between oncogenes and anti-oncogenes/tumor suppressor genes. | An oncogene is a gene that has the potential to cause cancer. antioncogenes are genes that protect a cell from the path to cancer. |
13, 14, 15 Questions go to Slides | |
16. Describe one advantage and two disadvantages of sexual reproduction, which involves meiosis. Part 1 | Advantages of sexual reproduction:
More genetic variation species
Children different than parents
Able to produce more offspring because of mate |
16. Describe one advantage and two disadvantages of sexual reproduction, which involves meiosis. Part 2 | Disadvantages of sexual reproduction:
Slower reproduction rate
Less reliable reproduction
Takes time and energy to find mate |
17. Explain how a karyotype is constructed and how it can be used. Part 1 | Karyotyping is a laboratory technique used to analyze chromosomes in order to look for any major chromosomal anomaly which may cause a genetic condition. SEE SLIDE FOR IMAGE |
17. Explain how a karyotype is constructed and how it can be used. Part 2 | Karyotypes are presented in a standard form. First, the total number of chromosomes is given, followed by a comma and the sex chromosome constitution. |
17. Explain how a karyotype is constructed and how it can be used. Part 3 | This shorthand description is followed by coding of any autosomal abnormalities. A few (simple) examples of this format are: |
17. Explain how a karyotype is constructed and how it can be used. Part 4 | • A normal male human: 46, XY
• Human with three X chromosomes (trisomy X): 47, XX |
18. Describe the role of sex cells in reproduction in regards to chromosome numbers. | Human body cells each contain 23 pairs of chromosomes. Parents pass on their genes to their offspring in their sex cells.
female sex cells are called egg cells, or ova. male sex cells are called sperm. SEE SLIDES FOR IMAGE |
19. Describe the process of crossing over (when it occurs and what happens) and how it increases variation. Part 1 | crossing over is a process in genetics by which the two chromosomes of a homologous pair exchange equal segments with each other. Crossing over occurs during prophase I of Meiosis I. |
19. Describe the process of crossing over (when it occurs and what happens) and how it increases variation. Part 2 | The crossing over makes more room for variability. When the chromosomes swap traits, they create different combinations of traits. The different combinations causes more variations in the products |
20. Describe how crossing over percentages can be used to create a gene map for a chromosome. Part 1 | Genetic linkage is the tendency of alleles that are located close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction. |
20. Describe how crossing over percentages can be used to create a gene map for a chromosome. Part 2 | Based on how close they are we can calculate the percentage rate that they will cross over together during crossing over of Prophase I of Meiosis I. |
Book Reading Review - Be sure to have read, outlined, studied, etc. the following sections from the book...... | 6.1 Chromosomes and Meiosis
5.1 The Cell Cycle
5.2 Mitosis and Cytokinesis
5.3 Regulation of the Cell Cycle
6.2 Process of Meiosis
6.6 Meiosis and Genetic Variation |
Book Questions Review - The following questions will also help you prepare for the test..... | p. 137 1-2
p. 142 1-5
p. 147 1-5
p. 171 1-5
p. 176 1-4
p. 191 1-4 |