Mitosis and meiosis - lecture 8

Question 1

What happens to the origin of replication when prokaryotes divide?

Answer 1

it doubles and is anchored to opposite sides of the cell

Question 2

what is prokaryote division called?

Answer 2

binary fission

Question 3

what are operons?

Answer 3

genes with similar functions clustered and co- expressed in bacteria

Question 4

Where are highly expressed genes situated in bacterial genomes?

Answer 4

Near the single origin of replication

Question 5

What is the centromere?

Answer 5

Constricted region of chromosome where the kinetochores form and spindle microtubules attach

Question 6

What is G1

Answer 6

Cell synthesis and growth

Question 7

What is the S phase?

Answer 7

DNA replication

Question 8

What is the G2

Answer 8

preparation for mitosis

Question 9

mitosis - prophase

Answer 9

chromosomes condense. Each chromosome possess two chromatids. The mitotic spindle from.

Question 10

mitosis - prometaphase

Answer 10

The nuclear membrane disintegrates. spindle microtubules attach to chromatids

Question 11

mitosis - metaphase

Answer 11

chromosomes line up on the metaphase plate

Question 12

mitosis - anaphase

Answer 12

sister chromatids separate and move toward opposite poles

Question 13

mitosis - telophase

Answer 13

chromosomes arrive at spindle poles. The nuclear membrane re-forms and the chromosomes relax

Question 14

middle prophase 1 - meiosis 1

Answer 14

Chromosomes begin to condense and the spindle forms

Question 15

late prophase 1 - meiosis 1

Answer 15

homologous chromosomes pair . crossing over takes place and nuclear membrane breaks down

Question 16

metaphase 1 - meiosis 1

Answer 16

homologous chromosomes pair up on metaphase plate

Question 17

anaphase 1 - meiosis 1

Answer 17

homologous chromosomes separate and move towards opposite poles

Question 18

telophase 1 - meiosis 1

Answer 18

chromosomes arrive at the spindle poles and the cytoplasm divides

Question 19

prophase 2 - meiosis 2

Answer 19

chromosomes recondense

Question 20

metaphase 2 - meiosis 2

Answer 20

individual chromosomes line up on the equatorial plate

Question 21

anaphase 2 - meiosis 2

Answer 21

sister chromatids separate and move toward opposite poles

Question 22

telophase 2 - meiosis 2

Answer 22

chromosomes arrive at the spindle poles and the cytoplasm divides

Question 23

When does recombination In meiosis occur?

Answer 23

prophase 1

Question 24

What are the 3 genetic sources of variation

Answer 24

• crossing over
• independent segregation
• gamete fusion