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Biology WarmUp_ Meiosis Vocabulary Review 1. What does it mean ..

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Biology WarmUp: Meiosis Vocabulary Review

1. What does it mean for two chromosomes to be,

“homologous?”

2. How many homologous pairs of chromosomes do human

beings have?

3. What is a, “tetrad?”

4. When are tetrads visible?

5. With regards to genetic diversity, what is the significance of

tetrad formation?

6. In fruit flies, the gene for star eye and speck wing are on the

same chromosome, yet offspring from star-eyed, speck-

winged parents often inherit star eyes without the speck wings.

How is this possible? Make a diagram to illustrate the process

that is responsible for the recombination.

Biology WarmUp: Meiosis Vocabulary Review

1. What does it mean for two chromosomes to be,

“homologous?”

If two chromosomes are homologous, they belong to the

same pair.

It is homologous chromosomes that line up together in

metaphase of meiosis.



Meiosis

Mitosis

Biology WarmUp: Meiosis Vocabulary Review

2. How many homologous pairs of chromosomes do

human beings have?



Human beings have 46 pairs of

chromosomes

2n = 46

That means they must have 23 pairs of

chromosomes

1n = 23

Biology WarmUp: Meiosis Vocabulary Review

3. What is a, “tetrad?”

During late prophase and

metaphase of meiosis I,

Tetrad

homologous chromosomes line up

in with their homologous pairs.

Since each chromosome is

composed of two sister

chromatids, the pair of

chromosomes consists of four

chromatids, hence the name,

“tetrad.”

Biology WarmUp: Meiosis Vocabulary Review

4. When are tetrads visible?

During late prophase and

metaphase of meiosis I,

Tetrad

homologous chromosomes line

up in with their homologous

pairs. Since each chromosome

is composed of two sister

chromatids, the pair of

chromosomes consists of four

chromatids, hence the name,

“tetrad.”

Biology WarmUp: Meiosis Vocabulary Review

5. With regards to genetic diversity, what

is the significance of tetrad formation?



Crossing over can occur only because

chromosomes form tetrads during meiosis.

Were it not for crossing over, traits on the

same chromosomes would always be

inherited together.

Biology WarmUp: Meiosis Vocabulary Review

6. In fruit flies, the gene for star eye and speck wing are on

the same chromosome, yet offspring from star-eyed, speck-

winged parents often inherit star eyes without the speck wings.

How is this possible? Make a diagram to illustrate the process

that is responsible for the recombination.

Though star eyes and

speck wing are inherited

together, they could be

separated by crossing

over, particularly if they

were found far apart on

the chromosome.



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