Chapter 13 Questions

Question 1

How many chromosomes are in a human in a somatic cell?

Answer 1

Humans have 46 chromosomes (23 homologous pairs) in their somatic cells

Question 2

How many homologous pairs of chromosomes are in a human diploid cell?

Answer 2

A diploid cell (2n) has two sets of chromosomes

Question 3

How many chromosomes are in a human gamete cell?

Answer 3

23 chromosomes

Question 4

What is the haploid number for human cells? What is the diploid number for human cells?

Answer 4

For humans, the haploid number is 23.

Diploid number is 46 (2n = 46)

Question 5

Is a karyotype made from a haploid or diploid cell?

Answer 5

diplopid

Question 6

What are the two sex chromosomes? Which pairing makes a female and which makes a male?

Answer 6

The sex chromosomes, which determine the sex of the individual, are called X and Y
Human females have a homologous pair of X chromosomes (XX)
Human males have one X and one Y chromosome (XY)

Question 7

Which sex chromosome is found in an unfertilized egg?

Answer 7

In an unfertilized egg (ovum), the sex chromosome is X

Question 8

Which sex chromosome may be found inside a sperm cell?

Answer 8

In a sperm cell, the sex chromosome may be either X or Y

Question 9

How many autosomes do humans have?

Answer 9

22

Question 10

Do cells that will ultimately undergo meiosis first go through the cell cycle?

Answer 10

yes

Question 11

Be able to explain the human life cycle

Answer 11

the generation-to-generation sequence of stages in the reproductive history of an organism

Question 12

What type of cell is produced directly after fertilization? How many chromosomes does this cell have in humans?

Answer 12

somatic - 46 chromosomes (23 homologous pairs)

Question 13

Are the chromosomes that will undergo meiosis duplicated or unduplicated?

Answer 13

duplicated

Question 14

Know the stages of meiosis and what happens during each stage

Answer 14

• -Meiosis I (reduction division), Prophase I, Metaphase I, Anaphase I, Telophase I
• -Meiosis II, Prophase II, Metaphase II, Anaphase II, Telophase II

Prophase I - homologs synapsis and crossing over
Metaphase I - homologs line up at metaphase plate
Anaphase I - pairs of homologous chromosomes separate
Telophase I - cytokinesis
Prophase II - spindle apparatus forms
Metaphase II - sister chromatids are arranged at the metaphase plate
Anaphase II - sister chromatids separate
Telophase II - chromosomes arrive at opposite poles, cytokinesis, nuclei form

Question 15

What special process occurs during prophase I of meiosis? What is the purpose of this process?

Answer 15

Crossing over -
non-sister chromatids exchange alleles (alternate versions of genes)
Leads to genetic diversity

Question 16

Which of the two meiotic divisions is also called the “reduction division”?

Answer 16

Meiosis I

Question 17

What does reduction division result in?

Answer 17

two haploid daughter cells

Question 18

Be able to identify the different stages of mitosis from an image and understand the way the chromosomes move during the different stages.

Answer 18

Mitosis produces 2 daughter cells while meiosis produces 4

Question 19

Know the differences between spermatogenesis and oogenesis

Answer 19

the size and arrangement of chromosomes is different. Spermatogenesis produces sperm and Oogenesis produces ovum

Question 20

Be able to compare mitosis vs. meiosis

Answer 20

Mitosis:
Type of Cells Produced - Somatic
Rounds of Division - 1
Ploidy of Parental Cell - Diploid
Ploidy of Daughter Cells -	Diploid
Number of Daughter Cells Produced - 2
Genetically Identical or 
Unique Daughter Cells?	- Identical

Meiosis:
Type of Cells Produced - Gametes
Rounds of Division - 2
Ploidy of Parental Cell - Diploid
Ploidy of Daughter Cells -	Haploid
Number of Daughter Cells Produced - 4
Genetically Identical or 
Unique Daughter Cells?	- Unique