Exam 2

Question 1

What do animal cells use in cytokinesis and what is it made up of?

Answer 1

Contractile ring made up of actin and myosin motor proteins

Question 2

How does the contractile ring work to split animal cells?

Answer 2

Radially pinches the cell into two (cleavage furrow)

Question 3

What do plant cells use in cytokinesis to split the cell?

Answer 3

Membrane bound vesicles accumulate in the middle of the cell creating a cell plate

Question 4

How does the temporary cell plate work to split plant cells?

Answer 4

The cell plate becomes a cell wall

Question 5

After which phases is a cell haploid?

Answer 5

Mitosis, meiosis I and meiosis II

Question 6

What is meiosis I also called?

Answer 6

A reduction division

Question 7

What does spermatogenesis result in?

Answer 7

4 haploid sperm cells

Question 8

What does oogenesis result in?

Answer 8

1 viable haploid egg cell and 3 haploid polar bodies

Question 9

What occurs during meiosis I?

Answer 9

Genetic variation (crossing over, independent assortment), homologs are separated, reduction division, and 2 haploid cells are produced (2 chromatid chromosomes)

Question 10

What occurs during meiosis II?

Answer 10

Chromatids are separated and 4 haploid cells are produced (1 chromatid chromosomes)

Question 11

What happens during prophase I?

Answer 11

Chromosomes condense, nuclear membrane breaks down, spindle poles begin to form, homologs pair up and form a tetrad

Question 12

What are tetrads held together by?

Answer 12

Synaptonemal complex proteins

Question 13

When does crossing over occur and what does it cause?

Answer 13

Prophase I; increase genetic variation

Question 14

What occurs during metaphase I?

Answer 14

Kinetochore microtubules connect to homologs, chromosomes line up along metaphase plate

Question 15

When does independent assortment occur and what does it cause?

Answer 15

Metaphase I; increases genetic diversity

Question 16

What occurs during anaphase I?

Answer 16

Homologs separate and are segregated to opposite spindle poles

Question 17

What occurs during telophase I?

Answer 17

Chromosomes decondense, spindle network breaks down, and nuclear membranes reform

Question 18

What happens at the end of meiosis I?

Answer 18

Cytokinesis: 1 diploid cell becomes 2 haploid cells
Interkinesis: cell rests before meiosis II; no DNA replication

Question 19

What occurs during meiosis II?

Answer 19

Chromatids are separated and 4 haploid cells are produced

Question 20

What occurs during prophase II?

Answer 20

Spindle poles form, chromosomes condense, and nuclear membrane breaks down

Question 21

What occurs during metaphase II?

Answer 21

Kinetochore microtubules attach to kinetochore proteins and chromosome line up at metaphase plate

Question 22

What occurs during anaphase II?

Answer 22

Chromatids get pulled apart

Question 23

What occurs during telophase II?

Answer 23

Nuclear membranes reform, spindle poles and microtubules break down and then cytokinesis

Question 24

Who is the scientist credited with founding modern science of genetics?

Answer 24

Gregor Mendel

Question 25

What ratio does a monohybrid cross of F1 result in?

Answer 25

3:1

Question 26

What is the law of segregation?

Answer 26

Maternal and paternal alleles segregate during gamete formation

Question 27

What does Mendel's law of dominance say?

Answer 27

Dominant vs recessive alleles

Question 28

What ratio does a dihybrid cross result in F2?

Answer 28

9:3:3:1

Question 29

What is the law of independent assortment?

Answer 29

Different genes are independent of other genes; color and shape alleles are assorted independently and must be on separate chromosomes

Question 30

A Mendelian pattern of inheritance only occurs if...

Answer 30

- each trait is controlled by a single gene - the gene only has 2 alleles - there is a clear dominant-recessive relationship

Question 31

What is incomplete dominance?

Answer 31

Parents with 2 different phenotypes can produce offspring with a 3rd phenotype; for example, Japanese 4 o'clock flowers

Question 32

What is codominance?

Answer 32

Heterozygote will have a combination of both parental phenotypes; for example, blood type

Question 33

What is epistasis?

Answer 33

One gene can affect the activity of another gene; for example, lab retrievers

Question 34

What is gene expression?

Answer 34

How a genotype is converted into a phenotype

Question 35

What is the Central Dogma?

Answer 35

DNA to (transcription) RNA to (translation) Protein

Question 36

Who were the scientists that found the relationship between genes and proteins?

Answer 36

George Beadle and Ed Tatum