C2: Genetic Background

Question 1

slender material inside the nucleus, usually found as colored bodies during cell division.

Answer 1

Chromosome

Question 2

Each chromosome is composed of ___ which separate during cell division

Answer 2

sister chromatids

Question 3

chromosomes has a __ or primary constriction (“waist line”), where the kinetochore proteins are attached

Answer 3

centromere

Question 4

____ is the sight of attachment of spindle fibers. The tip of the chromosome arm, needed for chromosome stability, is called ___

Answer 4

Kinetochore; telomeres

Question 5

Chromosomes are classified into types based on the position of the centromere: 4

Answer 5

Metacentric
Sub-metacentric
Acrocentric
Telocentric

Question 6

centromere is at the middle part of the chromosome

Answer 6

Metacentric

Question 7

centromere is sub-median; (near the middle); long-up & shortdown

Answer 7

Sub-metacentric

Question 8

centromere is at the subterminal portion; (3/4 at tip of chromosome); short-up & long-down

Answer 8

Acrocentric

Question 9

centromere is at the terminal end of the chromosome

Answer 9

Telocentric

Question 10

– complete set of chromosomes coming from either parent

Answer 10

Genome

Question 11

When cells divide, they go through an orderly series of events known as the
____.

Answer 11

cell cycle

Question 12

cell cycle is usually divided into ___ and ___

Answer 12

interphase, mitosis

Question 13

It enables a multicellular organism to grow and reach the adult size, replaces worn-out or damaged cells, and keeps the total number of cells in an adult organism relatively constant.

Answer 13

Cell division

Question 14

The Key Roles of Cell Division (4)

Answer 14

-unicellular organisms reproduce by cell division
-necessary for the repair and renewal of the worn-out tissues
-for the formation of new cells
-for cell growth, development and tissue differentiation

Question 15

An organism’s complete complement of genetic material is called its ___

Answer 15

genome

Question 16

replication and distribution of so much DNA is manageable because the
DNA molecules are packaged into ___

Answer 16

chromosomes

Question 17

The series of stages in the life of the cell is referred to as the ___

Answer 17

cell cycle.

Question 18

referred to as the “preparatory stage”; the longest phase; lasts for at least 90% of the total time

Answer 18

Interphase

Question 19

sub-phases of interphase: 3

Answer 19

G1 phase (first growth phase)
S phase (DNA synthesis)
G2 phase (second growth phase)

Question 20

grow in size; cell increases in volume
• cell is preparing the chemicals necessary for DNA synthesis
• ER, golgi apparatus, ribosomes, mitochondria and chloroplast are formed

Answer 20

G1 phase

Question 21

in this sub-phase of interphase:
• each of the chromosomes is replicated by the cell
• DNA synthesis or replication occurs

Answer 21

S phase (DNA synthesis)

Question 22

-double checks” the duplicated chromosomes for error;
-active synthesis of RNA and protein;
-formation of mitotic spindle occurs;
-doubled chromatin fiber folds to form a chromosome

Answer 22

G2 phase (second growth phase)

Question 23

period of nuclear division and cytokinesis .

Answer 23

M-phase (Mitotic phase)

Question 24

series of events wherein each cell divides to form to new daughter cells which are exactly identical to the mother cell

Answer 24

Mitosis

Question 25

division of the nucleus, with its contents (duplicated chromosomes: 2n), into two identical nuclei ▪ occurs in body or somatic cell

Answer 25

mitosis

Question 26

What events take place in Prophase (mitosis)? (5)

Answer 26

-Chromatin in the nucleus begins to condense, become visible in microscope -Chromosomes are thickened and become shortened -Centrioles begin moving to the opposite ends of the cell -Fibers extend from the centromeres -Nucleoli and nuclear membrane completely disappear

Question 27

What events take place in Metaphase (mitosis)? (4)

Answer 27

-chromosomes move along the middle of the cell -Centrioles reached the opposite end -Chromosomes become attached to the spindle fibers, move toward equator -Chromosomes tightly coiled and discrete, very condensed

Question 28

What events take place in Anaphase (mitosis)? (2)

Answer 28

-Early anaphase: centromeres are duplicated and start moving apart; sister chromatids start separating -Late anaphase: two identical sets of chromosomes move toward the opposite poles, spindle begine to disappear

Question 29

What events take place in Telophase (mitosis)?(4)

Answer 29

-Chromatids arrive at the opposite poles -enclosed in a nuclear membrane from their respective poles -Chromosomes begin to thin out, uncoil, and no longer visible -Spindle fibers disperse and cytokinesis may also begin

Question 30

this division of cytoplasm usually follows mitosis.

Answer 30

cytokinesis

Question 31

In plant tissues – the cytoplasm is divided via ____ where separation starts from the inside of the cell towards the periphery (in-out).

Answer 31

cell plate formation

Question 32

In animal tissues - cell cytokinesis occurs via ___ starting from the periphery(out-in).

Answer 32

furrowing or cleavage formation

Question 33

a.k.a resting phase; not actively preparing to divide

Answer 33

G0 phase

Question 34

process by which gametes are generated for reproduction

Answer 34

Meiosis

Question 35

occurs during gametogenesis; chromosome number turns to half (n)

Answer 35

Meiosis

Question 36

this meiosis involves the separation of homologous chromosomes resulting in two cells with haploid (n) chromosome number

Answer 36

Meiosis I or reductional division

Question 37

this meiosis happens when the two haploid cells proceed to the second division involving only the separation of chromatids producing four haploid cells

Answer 37

Meiosis II or equational division

Question 38

begins after the G2 phase

Answer 38

Meiosis I

Question 39

Substages of phrophase 1: (5)

Answer 39

Leptotene Zygotene Pachytene Diplotene Diakinesis

Question 40

This substage in Phrophase 1 is where synapsis occur, forming bivalents

Answer 40

zygotene

Question 41

This substage in Phrophase 1 is where crossing over happens

Answer 41

Pachytene

Question 42

What happens in Metaphase 1? (2)

Answer 42

-bivalents align at the metaphase/equatorial plane -Centromeres attached to the spindle fibers

Question 43

What happens in Anaphase 1? (1)

Answer 43

Univalents in each bivalent separate from each other

Question 44

What happens in Telophase 1? (1)

Answer 44

-Chromosomes regroup and their coiled structures begin to relax

Question 45

In some species, no cytokinesis happens after Meiosis I. a brief transitional stage called ___ occurs before the cell proceeds to the next stage.

Answer 45

interkinesis

Question 46

meiosis II starts with __ cells

Answer 46

haploid

Question 47

what is the product at the end of meiosis II?

Answer 47

formation of four (4) haploid daughter cells, each having only one chromosome of each homologous pair

Question 48

The sequential events of the cell are directed by a distinct ___ which is similar to a clock; like a check-point

Answer 48

cell cycle control system,

Question 49

Two types of regulatory proteins are involved in cell cycle control:

Answer 49

cyclins cyclin-dependent kinases (Cdks)

Question 50

each somatic cell nucleus has the same chromosomes—and therefore the same set of genes—as all other somatic cell nuclei. This is known as ____

Answer 50

genomic equivalence.

Question 51

what factors could elad to differential gene expression? (3)

Answer 51

-regulatory mechanisms targeting DNA access, -RNA production and processing, - protein synthesis and modification

Question 52

is a process in which based on the unique combination of genes that are active, or “expressed”, cells become different from one another.

Answer 52

Differential Gene Expression

Question 53

is a process by which cells become specialized and take on specific roles in an organism.

Answer 53

Differential Gene Expression

Question 54

gene expression can be regulated at four levels

Answer 54

Level 1: Differential gene transcription Level 2: Selective pre-messenger RNA processing Level 3: Selective messenger RNA translation Level 4: Differential posttranslational protein modification

Question 55

regulates which of the nuclear genes are transcribed into pre-messenger RNA.

Answer 55

Level 1: Differential gene transcription

Question 56

regulates which parts of the transcribed RNAs are able to enter the cytoplasm and become messenger RNAs.

Answer 56

Level 2: Selective pre-messenger RNA processing

Question 57

regulates which of the mRNAs in the cytoplasm are translated into proteins.

Answer 57

Level 3: Selective messenger RNA translation

Question 58

regulates which proteins are allowed to remain and/or function in the cell.

Answer 58

Level 4: Differential posttranslational protein modification

Question 59

sequence of events that enables the use and transfer of information to make the proteins of a cell

Answer 59

Central Dogma

Question 60

Proteins are not made directly from DNA, however; rather, the sequence of DNA bases is first copied, or transcribed, into a single-stranded polymer of similar molecules called _____, more commonly known as ___.

Answer 60

heterogeneous nuclear ribonucleic acids (hnRNA); pre-mRNA

Question 61

process of copying DNA into RNA;

Answer 61

Transcription

Question 62

RNA produced from a given gene is often referred to as a __

Answer 62

transcript

Question 63

the pre-mRNA strand will undergo processing to excise the noncoding domains and protect the ends of the strand to yield a ___ molecule

Answer 63

messenger RNA (mRNA)

Question 64

is transported out of the nucleus into the cytoplasm where it can interact with a ribosome and present its message for the synthesis of a specific protein; it also unveils the complementary sequence of DNA three bases at a time

Answer 64

messenger RNA (mRNA)

Question 65

leads to the synthesis of a polypeptide chain that will undergo protein folding and potential modification by the addition of various functional moieties, such as carbohydrates, phosphates, or cholesterol groups

Answer 65

Translation