Midterm 1

Question 1

Chromosome reproduction

Answer 1

Replicated chromosomes line up at the center of the cell, sister chromatids of each chromosome are pulled in each direction, cohesion molecule holds the chromatids together until separated by separase, then they separate.

Question 2

Prokaryotes

Answer 2

Bacteria

Archaea

Question 3

Three major organism groups

Answer 3

• Bacteria
• Archaea
• Eukaryotes

Question 4

Which two major groups are similar?

Answer 4

Bacteria and Archaea.
Transcription is similar to eukaryotes.
Archaea is more similar to eukaryotes than bacteria

Question 5

In eukaryotes

Answer 5

DNA with histones form tightly packed chromosomes called chromatin.
Helps regulate the accessibility of DNA to enzymes and other proteins.
Helps DNA fit into the nucleus

Question 6

Bacteria do not possess what?

Answer 6

Histones

Question 7

Where are genes of prokaryotic cells located?

Answer 7

on a single molecule of double-stranded DNA

Question 8

Where are genes of eukaryotic cells located?

Answer 8

Multiple, usually linear, DNA molecules.

They require a mechanism to ensure that each copy is transmitted to each new cell.

Question 9

Are viruses eukaryotes or prokaryotes?

Answer 9

They are neither because they do not have cell structure.

Viruses can only reproduce within the host.

Question 10

What does cell reproduction require

Answer 10

the copying of genetic material, separation of copies, and cell division.

Question 11

Prokaryotic cell reproduction

Answer 11

Binary fission
The replication occurs at the origin of replication
Origin of replication goes to different ends of the cell
The cell divides and each cell has identical copies of the original chromosome.

Question 12

Eukaryotic cell reproduction

Answer 12

Chromosomes are separated from the cytoplasm by the nuclear membrane.

Question 13

eukaryotic chromosomes

Answer 13

Two sets of chromosomes, one from male parent other from female parent.

Question 14

Diploid cells

Answer 14

carry two sets of genetic information

Question 15

Ploidy

Answer 15

indicates how many sets of genetic information a cell possesses.

Question 16

haploid cells

Answer 16

contain a single set of chromosomes

Question 17

polyploid cells

Answer 17

contain more than two sets of chromosomes

Question 18

chromosome structure

Answer 18

Centromere -> Constricted region, acts as an attachment point of spindle microtubules, responsibly for moving chromosomes in cell division.

Telomere -> Has DNA sequences and proteins at the tip of the chromosome. Functions in protection and stability, if the end breaks the chromosome degrades.

Origin of replication -> where DNA synthesis begins

Question 19

Sister chromatids

Answer 19

two identical copies of chromosomes that are held together at the centromere, single DNA molecule.

Question 20

Centromere structure

Answer 20

Metacentric

Submetacentric

Acrocentric

Telocentric

Question 21

Cell cycle

Answer 21

Interphase

M phase

Question 22

Interphase

Answer 22

Cell grows and develops, DNA synthesizes and RNA/proteins are being produced.

G1 -> cell grows proteins for cell division

G1/S checkpoint -> ensures that all components of DNA replication is functional

S phase -> DNA synthesis, chromosomes are duplicated. (each chromosome = two sister chromatids)

G2 -> Biochemical events occur for cell division

G2/M -> ensures that all components of the molecular machinery required of M phase are functional

Question 23

M phase

Answer 23

Sister chromatids separate and cell undergoes division.

Prophase -> Condensins bind to DNA and start condensation

Prometaphase -> disintegration of nuclear membrane. Chromosome attaches to microtubules from opposite sides

Metaphase -> Chromosome arrange in a single pane in-between two centrosomes.

Anaphase -> Sister chromatids break apart and separate, chromosomes move to opposite sides.

Telophase -> Each is a separate chromosome, nuclear membrane reforms and creates two nuclei. Cytokinesis occurs.

Question 24

Genetic consequences of the cell cycle

Answer 24

Cell cycle produces two cells with the same genetic instructions.

Cells produced contain a complement of chromosomes

No net reduction or increase in chromosome number

Not all cells are identical in cytoplasmic content

Question 25

Meiosis I

Answer 25

``` Interphase Prophase I Metaphase I Anaphase I Telophase I ```

Question 26

Prophase I

Answer 26

homologous chromosomes pair and form synapses

Question 27

Crossing over

Answer 27

Homologous chromosomes exchange genetic information Creates genetic variation

Question 28

Metaphase I

Answer 28

Homologous pairs of chromosomes align along the metaphase plate, microtubule from one spindle attaches to a chromosome of a homologous pair and a different microtubule attaches to another pair.

Question 29

Anaphase I

Answer 29

Chromosomes are pulled towards opposite poles. Homologous chromosomes separate, sister chromatid attaches and travels together.

Question 30

Telophase I

Answer 30

chromosomes arrive at the spindle poles and cytoplasm divides

Question 31

Meiosis II

Answer 31

``` Interkinesis Prophase II Metaphase II Anaphase II Telophase II ```

Question 32

Prophase II

Answer 32

Chromosomes re condense, spindle reforms and nuclear membrane breaks down.

Question 33

Metaphase II

Answer 33

Replicated chromosomes line up on the metaphase plate, sister chromosomes facing opposite poles

Question 34

Anaphase II

Answer 34

Sister chromatids separate and pulled to opposite poles, each chromatid is a chromosome

Question 35

Telophase II

Answer 35

Chromosome arrives at spindle and nuclear membrane reforms and cytoplasm divides.