Question 1

Which of the following best describes the result of a dehydration synthesis reaction between two glucose molecules, given that the formula for glucose is $$\mathrm{C_6H_{12}O_6$}$$?

Accepted Answer

The formula for maltose is $$\mathrm{C$$_{12}$$H_{22}O$$_{11}}$$ because a water molecule ($$\mathrm{H_2O}$) is lost during the reaction.

Question 2

In the Punnett square shown, a red-eyed female Drosophila ($$X^R X^R) is $$crossed with a white-eyed male ($$X^r Y). $$What are the expected genotypes and phenotypes of the offspring?

Accepted Answer

All offspring will have red eyes; females will be $$X^R X^r$$ and males will be $$X^R Y.$$

Question 3

Why is it more probable for male Drosophila to be white-eyed when the white-eye allele is X-linked?

Accepted Answer

Males have only one X chromosome, so a single recessive allele ($$X^r) $$will result in the white-eye phenotype.

Question 4

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.

Question 5

During meiosis, crossing over occurs in which phase, and what is its significance?

Accepted Answer

Crossing over occurs during prophase I and increases genetic variation by exchanging segments between homologous chromosomes.

Question 6

A couple has genotypes $$AA$$ and $$Aa$$ for a gene with dominant allele $$A$$ and recessive allele $$a. $$What proportion of their offspring will be homozygous dominant, homozygous recessive, and heterozygous?

Accepted Answer

50% homozygous dominant ($$AA$$), 0% homozygous recessive ($$aa$$), 50% heterozygous ($$Aa)$$

Question 7

Which of the following best describes the process of denaturation in proteins?

Accepted Answer

Denaturation is the loss of a protein's native structure due to external stress, such as heat or pH changes, resulting in loss of function.

Question 8

Which of the following is NOT a function of enzymes in biological systems?

Accepted Answer

Enzymes are consumed during the reaction and cannot be reused.

Question 9

Which of the following best explains the Law of Segregation?

Accepted Answer

Each individual has two alleles for each gene, and these alleles separate during gamete formation so that each gamete carries only one allele.

Question 10

Which of the following is a real-world example of codominance?

Accepted Answer

AB blood type in humans, where both A and B alleles are expressed equally.

Question 11

Which of the following best describes the difference between a monohybrid and a dihybrid cross?

Accepted Answer

A monohybrid cross involves one gene, while a dihybrid cross involves two genes.

Question 12

Which of the following best describes the role of phospholipids in cell membranes?

Accepted Answer

Phospholipids form a bilayer that acts as a barrier, with hydrophilic heads facing outward and hydrophobic tails facing inward.

Question 13

Which of the following best describes the concept of independent assortment?

Accepted Answer

Independent assortment refers to the random distribution of homologous chromosomes during meiosis, resulting in genetic variation.

Question 14

Which of the following best describes a carrier in a pedigree analysis?

Accepted Answer

A carrier is an individual who has one copy of a recessive allele and can pass it to offspring without showing symptoms.

Question 15

Which of the following best describes the difference between a gene and a locus?

Accepted Answer

A gene is a unit of hereditary information, while a locus is the physical location of a gene on a chromosome.

Question 16

Which of the following best describes the outcome of nondisjunction during meiosis?

Accepted Answer

Nondisjunction results in gametes with abnormal numbers of chromosomes, leading to conditions such as trisomy or monosomy.

Question 17

Which of the following best describes the structure of DNA?

Accepted Answer

DNA is a double helix composed of two polynucleotide strands held together by hydrogen bonds between complementary bases.

Question 18

Which of the following best describes the difference between a polypeptide and a protein?

Accepted Answer

A polypeptide is a chain of amino acids, while a protein is a functional molecule formed by one or more polypeptides folded into a specific shape.

Exam 3 Study Guide: Macromolecules, Meiosis, Mendelian Genetics, and Chromosomal Inheritance

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