CELL DIVISION (LEC)

Question 1

Most cells of the human body undergo _____________, the process by which cells reproduce themselves

Answer 1

Cell division

Question 2

The two types of cell division—

Answer 2

•somatic cell division
•reproductive cell division

Question 3

2 phases of somatic cell division

Answer 3

Mitosis and Cytokinesis

Question 4

Mitosis

Answer 4

Nuclear Division

Question 5

Cytokinesis

Answer 5

Cytoplasmic division

Question 6

produce two genetically identical cells, each with the same number and kind of chromosomes as the original cell

Answer 6

Somatic Cell Division

Question 7

Reproductive Cell Division produces ______________ the cells needed to form the next generation of sexually reproducing organisms

Answer 7

gametes

Question 8

produces gametes, the cells needed to form the next generation of sexually reproducing organisms

Answer 8

Reproductive Cell Division

Question 9

is an orderly sequence of events in which a somatic cell duplicates its contents and divides in two

Answer 9

cell cycle

Question 10

Human cells contain

Answer 10

23 pairs of chromosomes, for a total of 46

Question 11

The two chromosomes that make up each pair are called

Answer 11

homologous chromosomes or homologs

Question 12

The exception to this rule is one pair of chromosomes called the

Answer 12

sex chromosomes

Question 13

females the homologous pair of sex chromosomes consists of two large

Answer 13

X chromosomes

Question 14

males the pair consists of an

Answer 14

X and a much smaller Y chromosome

Question 15

three phases of Interphase

Answer 15

G1, S, G2

Question 16

cell metabolically active; duplicates organelles and cytosilic components; centrosome replication begins

Answer 16

G1 phase

Question 17

What happens in G1 phase

Answer 17

cell metabolically active; duplicates organelles and cytosilic components; centrosome replication begins

Question 18

DNA replicated

Answer 18

S phase

Question 19

Cell growth continues; enzymes and other proteins are synthesized; centrosome replication completed

Answer 19

G2 phase

Question 20

What happens in G2 phase

Answer 20

Cell growth continues; enzymes and other proteins are synthesized; centrosome replication completed

Question 21

exit from cell cycle (non-dividing cell)

Answer 21

G0

Question 22

The process results in the exact partitioning of genetic information

Answer 22

Mitosis/Mitotic Phase

Question 23

For convenience, biologists divide the process into four stages:

Answer 23

PMAT
Prophase, Metaphase, Anaphase, Telophase

Question 24

prophase chromosome consists of a pair of identical strands called

Answer 24

chromatids

Question 25

holds the chromatid pair together

Answer 25

centromere

Question 26

At the outside of each centromere is a protein complex known as the

Answer 26

kinetochore

Question 27

a football-shaped assembly of microtubules that attach to the kinetochore

Answer 27

mitotic spindle

Question 28

of the mitotic spindle align the centromeres of the chromatid pairs at the exact center of the mitotic spindle

Answer 28

microtubules

Question 29

This plane of alignment of the centromeres is called the

Answer 29

metaphase plate (equatorial plane)

Question 30

Once separated, the chromatids are termed

Answer 30

chromosomes

Question 31

-prophase chromosome consists of a pair of identical strands called chromatids.
- centromere holds the chromatid pair together.
- At the outside of each centromere is a protein complex known as the kinetochore
mitotic spindle, a football-shaped assembly of microtubules that attach to the kinetochore

Answer 31

Prophase

Question 32

• The microtubules of the mitotic spindle align the centromeres of the chromatid pairs at the exact center of the mitotic spindle.
• This plane of alignment of the centromeres is called the metaphase plate (equatorial plane).

Answer 32

Metaphase

Question 33

-The centromeres split, separating the two members of each chromatid pair, which move toward opposite poles of the cell.
-Once separated, the chromatids are termed chromosomes.

Answer 33

Anaphase

Question 34

This process usually begins in late anaphase with the formation of a cleavage furrow, a slight indentation of the plasma membrane, and is completed after telophase.

Answer 34

Cytokines

Question 35

This process usually begins in late anaphase with the formation of a __________________, a slight indentation of the plasma membrane, and is completed after telophase.

Answer 35

Cleavage furrow

Question 36

As a result, gametes contain a single set of 23 chromosomes and thus are

Answer 36

Haploid

Question 37

restores the diploid number of chromosomes

Answer 37

Fertilization

Question 38

meiosis occurs in two successive stages:

Answer 38

meiosis I
meiosis II

Question 39

Two sister chromatids of each pair of homologous
chromosomes pair off , an event called ___________

Answer 39

synapsis

Question 40

The resulting four chromatids form a structure called a

Answer 40

tetrad

Question 41

Such an exchange between parts of nonsister (genetically
different) chromatids is called

Answer 41

crossing -over

Question 42

-Two sister chromatids of each pair of homologous chromosomes pair off , an event called synapsis.
-The resulting four chromatids form a structure called a tetrad.
-Parts of the chromatids of two homologous chromosomes may be exchanged with one another.
Such an exchange between parts of nonsister (genetically different) chromatids is called crossing-over.

Answer 42

Prophase I