mutation - defined as a permanent
change in the DNA sequence. Repair gene mutations can result in serious consequences such as cancer
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Exercises 1 : Read the following words and guess their meaning:
determine, scientist, discover, protein, observe, pattern, X-ray, method, investigate, molecular, substance,
puzzle, present, determine, nucleic acid, nitrogenous, phosphate, bond, covalent, clockwise, oxygen,
hydrogen, strand
Exercise 2: Multiple choice questions:
1. What is a chromosome made of?
a. Acetic orcein
b. RNA
c. DNA
d. Protein
2. How many chromosomes should a typical human being have?
a. 62
b. 56
c. 46
d. 23
3. Which chromosome arrangement would produce a masculine human?
a. XY
b. XX
c. YY
d. XXX
4. Which of the following statements regarding mitosis is untrue?
a. Chromosomes split to create daughter chromatids during the first phases of cell division.
b. Mitosis is a process utilized to replace damaged, aging cells.
c. Lone formation occurs when two identical daughter cells are produced.
d. The technique results in the introduction of genetic variation.
5. Which of the following assertions about meiosis is true?
a. The technique results in the introduction of genetic variation.
b. Old, worn-out cells are replaced during meiosis.
c. Clones, or two identical daughter cells, are created.
d. Asexual reproduction involves the meiotic process.
Key definitions Deoxyribose - a pentose sugar, C5H10O4, that is a component of DNA's structure
Phosphate group - the part of the DNA double helix that supports the molecule's structure
Nitrogenous base - a nitrogen-containing compound with base-like chemical characteristics