Test III Ch.8

Question 1

Cell Life Cycle

Answer 1

Constitutes Cell growth and reproduction

Question 2

Cell growth

Answer 2

• genetic information (in DNA) codes for the structural and function al proteins needed for cell survival
• Interphase

Question 3

Cell reproduction

Answer 3

genetic information is passed from one generation to the next (most often: mitosis)

Question 4

Centromere

Answer 4

Protein that holds chromatids together

Question 5

Chromosome

Answer 5

one long piece of DNA

Question 6

Sister Chromatids

Answer 6

two Chromatids held together by a Centromere

Question 7

Interphase

Answer 7

• growth phase of the cell life cycle can be subdivided into
• G1(first growth phase)
• S (the DNA synthesis phase)
• G2 (the second growth phase)

Question 8

G1

Answer 8

• First step of Interphase
• production of cytoplasm, more cell material is made
• Right after division so the cell is (recovering) from the division

Question 9

S

Answer 9

The DNA synthesis phase

• Replication of the genome; done by base paring
• Chromosome duplication

Question 10

G2

Answer 10

The second growth phase

-in preparation for the next cell division

Question 11

Mitosis

Answer 11

• Cell division that results in 2 genetically identical daughter cells
• Used for growth, repair, replacement, asexual reproduction

Question 12

Meiosis

Answer 12

• Cell division that results in 4 haploid, genetically unique daughter cells
• Used for production of gametes (sexual reproduction)

Question 13

Prophase

Answer 13

First Stage of Mitosis

• DNA coils up into chromosomes
• Nuclear envelope begins to decompose
• Centrioles/microtubules separate and begin building spindle fibers

Question 14

Metaphase

Answer 14

Second Stage of Mitosis

• Chromosomes line up in the middle of the cell
• Spindle fibers attach to the chromosome at the centromere

Question 15

Anaphase

Answer 15

3rd stage of Mitosis

• the spindle fibers pull the chromosomes apart at the centromere
• the split chromosomes migrate towards opposite sides of the cell

Question 16

Telophase

Answer 16

4th stage of mitosis

• The chromosomes begin to uncoil
• Nuclear envelope reforms
• Spindle fibers decompose
• Cytokinesis occurs

Question 17

Cytokinesis

Answer 17

Part of Telophase (4th stage of Mitosis)

• When the plasma membrane pulls together and pinches off into two cells
• Cleavage furrow

Question 18

Cell Growth consists of what phase? What three sub-phases?

Answer 18

Interphase:

• G1
• S
• G2

Question 19

Mitosis consists of what four stages?

Answer 19

• Prophase
• Metaphase
• Anaphase
• Telophase

Question 20

What sub-phase occurs during Telophase

Answer 20

Cytokinesis

Question 21

Humans Chromosomes

Answer 21

46 total chromosomes

• 23 pairs (diploid) one of each chromosome is inherited from each parent
• 1-22 are called autosome (not sex cells) and are numbered by size
• Last pair consists of an XX(female) or XY(male)

Question 22

Haploid Gametes vs. Diploid Zygote

Answer 22

Diploid Zygote (2n=46) 
Haploid Gametes (n=23) ex. Egg cell, Sperm Cell
(in Humans)

Question 23

Meiosis

Answer 23

• Diploid parent cell becomes 4 haploid daughter cells
• This happens across 2 divisions
• Meiosis I
• Meiosis II

Question 24

Meiosis I consists of what 4 phases

Answer 24

Homologous Chromosomes separate 
Creates diversity
-Prophase I
-Metaphase I
-Anaphase I
-Telophase I

Question 25

Meiosis II consists of what 4 phases

Answer 25

Sister chromosomes separate 
Turns diploid to Haploid cells
-Prophase II
-Metaphase II
-Anaphase II
-Telophase II

Question 26

Prophase I

Answer 26

the chromosomes recombine in a process called crossing over

Question 27

Metaphase I

Answer 27

the chromosomes are independently assorted

Question 28

Nondisjunction

Answer 28

• when a pair of chromosomes fails to separate during meiosis
• Chromosomal abnormalities are the cause of certain congenital disorders

Question 29

congenital

Answer 29

Born with

Question 30

Gametes

Answer 30

sexual reproduction cells

Question 31

Traits are the result of inherited sequences of DNA called ______. They can have variations called _______.
ex. The _____ for flower color in peas has 2 ______.

Answer 31

Gene. Alleles

Question 32

Diploid organisms carry ____ copies of each Gene

Answer 32

2 copies.

If you have two identical copies you are said to be Homozygous for that trait

Question 33

Homozygous

Answer 33

Has 2 identical alleles for a trait

Question 34

Heterozygous

Answer 34

2 different alleles for a trait

Question 35

What happens when an organism is heterozygous for a trait

Answer 35

They have two different alleles often one allele is expressed. this is the dominate allele

Question 36

How often are dominant alleles expressed?

Answer 36

Always

Question 37

Ones Genotype is

Answer 37

Their combination of Allele

Question 38

Ones phenotype

Answer 38

What you can see

Pheno- greek for eye

Question 39

Law of segregation

Answer 39

During meiosis, the chromosomes pairs divide and the gametes are haploid.

• alleles in an organism are segregated in the gametes
• offspring only inherit one allele from each parent ( resulting in a diploid zygote

Question 40

Law of independent assortment:

Answer 40

• Pairs or alleles sort independently of each other

- The inheritance of one trait has no effect on the inheritance of the other

Question 41

Law of Dominance

Answer 41

Dominant alleles are always expressed and the un expressed trait is recessive

Question 42

Pedigree

Answer 42

Family tree showing the genetic history