Exam 2

Question 1

Define characters

Answer 1

Observable physical features

Question 2

List an example of a character

Answer 2

Flower color, seed shape

Question 3

Define traits

Answer 3

Forms of a character

Question 4

List examples of traits

Answer 4

Purple flowers, wrinkled seeds

Question 5

In what organisms are cell division and reproduction the same

Answer 5

Single-celled organisms

Question 6

What is the difference between an asexual and a sexual life cycle?

Answer 6

An asexual life cycle has asexual cell division, meaning offspring are identical to each other and the parent. A sexual life cycle has meiosis and fertilization, so offspring differ from one another and their parents.

Question 7

What is the difference between a diplontic and a haplontic life cycle?

Answer 7

In a diplontic life cycle, the mature organism is diploid and the gametes are the only haploid stage. In a haplontic life cycle, the mature organism is haploid and the zygote is the only diploid.

Question 8

What event occurs during G1?

Answer 8

prepare for cell division

Question 9

What event occurs during S?

Answer 9

DNA Replication

Question 10

What event occurs during G2?

Answer 10

preparation for mitosis

Question 11

What event occurs during M?

Answer 11

mitosis and cytokinesis

Question 12

What event occurs at prophase?

Answer 12

Prophase: centrosomes divide (if present), chromosomes condense, spindle starts to form

Question 13

What event occurs at prometaphase?

Answer 13

Prometaphase: nuclear envelope breaks down, chromosomes attach to fully formed spindle

Question 14

What event occurs at metaphase?

Answer 14

Metaphase: alignment of replicated chromosomes on the metaphase plate.

Question 15

What event occurs at anaphase?

Answer 15

Anaphase: centromere division and movement of sister chromatids to opposite poles.

Question 16

What event occurs at telophase?

Answer 16

Telophase: decondensing of chromosomes and re-formation of nuclear membranes.

Question 17

How does binary fission differ from the mitotic cell cycle?

Answer 17

The main difference is the co-occurrence of DNA replication and segregation in binary fission. Binary fission in prokaryotes does not use a microtubule spindle.

Question 18

Define aneuploidy

Answer 18

A condition in which the number of one or more chromosomes is either lacking or in excess.

Question 19

Define necrosis

Answer 19

occurs in multicellular organisms when a cell is damaged or is starved of nutrients, oxygen, or water.
Necrotic cells often swell up and burst, releasing their contents into the extracellular environment. This process often results in inflammation, which also affects surrounding tissues. When a multicellular individual dies, all of its cells will soon succumb to this kind of death.

Question 20

What difference between plants and animals best explains why they undergo cytokinesis in different ways?

Answer 20

The rigid cell wall of a plant cannot be deformed by a contractile ring

Question 21

How does cytokinesis begin in animal cells?

Answer 21

furrowing of the cell membrane

Question 22

Define contractile ring

Answer 22

the contractile ring generates the constricting force to separate one cell into two cells.

Answer 23

Telophase

Question 24

In meiosis, DNA replicates____the nucleus divides

Answer 24

one less time than

Question 25

Which of the following is most likely to lead to aneuploidy?

Answer 25

Nondisjunction

Question 26

In the haplontic life cycle, the mature organism is haploid and the _______ is the only diploid stage

Answer 26

Zygote

Question 27

Which statement about plant cytokinesis is true?

Answer 27

Vesicles fuse to form a cell plate

Question 28

Define centrosomes

Answer 28

?

Question 29

Define chiasmata

Answer 29

An X-shaped connection between paired homologous chromosomes in prophase I of meiosis. A chiasma is the visible manifestation of crossing over between homologous chromosomes.

Question 30

A monosomic individual has 27 chromosomes. What is the haploid chromosome number?

Answer 30

14

Question 31

Caspases play a role in the process of

Answer 31

apoptosis

Question 32

With respect to what happens with the nuclear envelope, telophase is most like the opposite of

Answer 32

prometaphase

Question 33

When a cell, or organism, has an unequal number of copies of each chromosome, it is

Answer 33

aneuploid

Question 34

Maternal chromosome 1, paternal chromosome 2, and maternal chromosome 3 go to the same pole during meiosis. This is an example of

Answer 34

independent assortment

Question 35

Hayflick limit

Answer 35

The maximum number of cell divisions for a normal (human) cell before apoptosis occurs (due to telomere shortening).

Question 36

The ori region is the site where which of the following starts?

Answer 36

DNA Replication

Question 37

A key event controlling the transition from one cell cycle phase to the next is the synthesis and subsequent breakdown of a particular

Answer 37

Cyclin

Question 38

DNA replication and segregation co-occur in

Answer 38

binary fission

Question 39

If greater than normal amounts of the G1/S cyclin-CDK were produced, the most likely result would be ______ of RB and ______of the cell cycle.

Answer 39

more phosphorylation; acceleration

Question 40

What action do CDKs perform on target proteins?

Answer 40

they add a phosphate group to the protein

Question 41

Cells that do not divide usually arrest during

Answer 41

G1

Question 42

What is the essential difference between necrosis and apoptosis?

Answer 42

In apoptosis, cell death is part of the normal developmental process; in necrosis, cell death is the result of something going wrong.

Question 43

Mitosis/Meiosis?:Homologous chromosomes come together and line up along their entire lengths

Answer 43

only in meiosis