Chapter 2: Chromosomes and Cells

Question 1

What is a Model Genetic Organism?

Answer 1

Organisms with characteristics that make them useful for genetic analysis

Question 2

What are some common characteristics of Model Organism (6)

Answer 2

1. Short generation time
2. Production of numerous progeny
3. The ability to carry out controlled genetic crosses
4. The ability to be reared in a lab environment
5. The availability of numerous genetic variants
6. An accumulated body of knowledge about their genetic systems

Question 3

What are the difference in Nucleus, Cell diameter, Genome, DNA, amount of DNA, and membrane-bound organelles with prokaryotes and eukaryotes?

Answer 3

Question 4

What helps organize DNA molecules?

Answer 4

Histones form tightly packed chromosomes to help regulated accessibility and enable DNA to fit into nucleus

• Bacteria do not have histones
• Archaea have histones

Question 5

Are viruses prokaryotic or eukaryotic?

Answer 5

Neither, viruses are not alive

Question 6

What is the make up of a virus?

Answer 6

1. Outer protein coat
2. Inner nucleic acid

Question 7

What does Haploid mean?

Answer 7

Cell that contains 1 copy of every chromosome

Question 8

What does Diploid mean?

Answer 8

Cell that contains 2 copies of every chromosome

Question 9

1. How many chromosomes
2. How many DNA molecules
3. Diploid or Haploid

Answer 9

1. 2 chromosomes
2. 4 DNA molecules
3. Haploid

Question 10

1. How many chromosomes
2. How many DNA molecules
3. Diploid or Haploid

Answer 10

1. 2 chromosomes
2. 2 DNA molecules
3. Diploid

Question 11

1. How many chromosomes 2. How many DNA molecules 3. Diploid or Haploid

Answer 11

1. 1 chromosome
2. 1 DNA molecule
3. Haploid

Question 12

1. How many chromosomes
2. How many DNA molecules
3. Diploid or Haploid

Answer 12

1. 1 Chromosome
2. 2 DNA molecules
3. Haploid

Question 13

What is Submetacentric, Metacentric, Telocentric, and Acrocentric

Answer 13

Question 14

What is a karyotype?

Answer 14

Visual display of an individuals chromosome

Question 15

What is a gene?

Answer 15

Genetic factor that helps determine a trait; DNA that leads to transcription of an RNA

Question 16

how are homologous chromosomes related to alleles?

Answer 16

1. Homologous chromosomes have same genes, but may have different forms of gene (alleles)
2. We get one chromosome from mom and one from dad. These pairs of chromosomes are called homologous chromosomes

Question 17

What are telomeres?

Answer 17

Specific DNA sequences and associated protein located at the tips of linear DNA

Question 18

What is a centromere?

Answer 18

The centromere is a constricted region of the chromosome where the kinetochores form and the spindle microtubules attach

Question 19

What are the eukaryotic cell cycles?

Answer 19

Interphase

1. G1
2. S
3. G2

M phase

4. M (mitosis)
5. C (cytokinesis)

Question 20

What occurs during the G1 phase?

Answer 20

Grows and proteins necessary for cell division are synthesized

Question 21

What occurs during prophase of mitosis?

Answer 21

Chromosomes condense.

Each chromosome possesses two chromatids.

The mitotic spindle forms

Question 22

What happens during prometaphase of mitosis

Answer 22

The nuclear membrane disintegrates.

Spindle microtubules attach to chromatids

Question 23

What happens during Metaphase of mitosis?

Answer 23

Chromosomes line up on the metaphase plate

Question 24

What happens during anaphase of mitosis

Answer 24

Separation

Question 25

What molecule is cleaved in order for anaphase to occur?

Answer 25

Cohesin keep sister chromatids together, must be cleaved for anaphase to occur

Question 26

What is shugoshin?

Answer 26

A protein that protects cohesin from cleave during anaphase I

Question 27

What occurs during prophase of Meiosis I?

Answer 27

***Synapsis is the connect of homologous chromosomes to form a tetrad and to allow crossing over.*** Synapsis: Close pairing of homologous chromosomes Tetrad: Closely associated four-sister chromatids of two homologous chromosomes Crossing over: exchange of genetic info between non-sister chromatids

Question 28

What is the synaptonemal complex?

Answer 28

A protein structure that forms between homologous chromosomes during meiosis and is thought to mediate synapsis and recombination

Question 29

What is crossing over?

Answer 29

Takes place in prophase 1, refers to the exchange of genetic material between non-sister chromatids

Question 30

What is independent assortment?

Answer 30

**how different genes independently separate from one another**