Q: In a laboratory experiment, students are asked to calculate the rate of photosynthesis using DCPIP. Which formula should they use to convert absorbance values to DCPIP concentration?

$$\text{DCPIP concentration (mM)} = \frac{\text{Abs}}{\text{slope of standard curve}}$$

Question 1

Which of the following best describes the main purpose of meiosis in sexually reproducing organisms?

Accepted Answer

To reduce the chromosome number by half, creating haploid gametes

Question 2

During which phase of meiosis does crossing over occur, and what is its significance?

Accepted Answer

Prophase I; it increases genetic variation by exchanging DNA between homologous chromosomes

Question 3

A human cell with 46 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

$$23$$

Question 4

Which event during meiosis is responsible for the independent assortment of genes?

Accepted Answer

Random orientation of tetrads at Metaphase I

Question 5

If a diploid organism has $$2n = 8$$, how many possible combinations of chromosomes can be produced in its gametes due to independent assortment alone?

Accepted Answer

$$2^4 = 16$

Question 6

Which of the following is a key difference between spermatogenesis and oogenesis in humans?

Accepted Answer

Oogenesis produces one mature ovum and polar bodies, while spermatogenesis produces four mature sperm

Question 7

Which of the following best explains why siblings from the same parents can look different from each other?

Accepted Answer

Crossing over and independent assortment during meiosis create unique combinations of alleles

Question 8

What is the result of nondisjunction during Anaphase I of meiosis?

Accepted Answer

Some gametes have an extra chromosome, while others are missing one

Question 9

Which of the following equations correctly represents the relationship between the number of chromosome types ($$n) $$and the total chromosome number in a diploid cell?

Accepted Answer

$$2n = 2 	imes n$$

Question 10

A scientist observes a cell with homologous chromosomes paired and crossing over occurring. Which stage of meiosis is this cell in?

Accepted Answer

Prophase I

Question 11

Which of the following is NOT a source of genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during S phase

Question 12

In a laboratory experiment, students are asked to calculate the rate of photosynthesis using DCPIP. Which formula should they use to convert absorbance values to DCPIP concentration?

Accepted Answer

$$	ext{DCPIP concentration (mM)} = \frac{	ext{Abs}}{	ext{slope of standard curve}}$$

Question 13

Which of the following best describes a homologous chromosome pair?

Accepted Answer

Two chromosomes of the same type, one from each parent, with the same genes but possibly different alleles

Question 14

Why does meiosis require two rounds of cell division?

Accepted Answer

To reduce the chromosome number by half and then separate sister chromatids

Question 15

A mutation prevents crossing over during meiosis. What is the most likely consequence for the offspring?

Accepted Answer

Offspring will have reduced genetic diversity

Question 16

Which of the following steps is unique to meiosis and does NOT occur in mitosis?

Accepted Answer

Pairing of homologous chromosomes (synapsis)

Question 17

A student is analyzing the results of a dihybrid cross in fruit flies. Which process during meiosis explains the appearance of new combinations of traits not found in either parent?

Accepted Answer

Crossing over between homologous chromosomes

Question 18

Which of the following best explains why only one ovum is produced from oogenesis, while four sperm are produced from spermatogenesis?

Accepted Answer

Oogenesis involves unequal division of cytoplasm, resulting in one large ovum and polar bodies

Question 19

Which of the following is the correct sequence of events in meiosis I?

Accepted Answer

Prophase I, Metaphase I, Anaphase I, Telophase I

Chapter 13 Lecture

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