Bio exam 3

Question 1

What does Meiosis create?

Answer 1

Gametes (genetically different haploid cells)

Question 2

What is the order in which Meiosis functions?

Answer 2

Meiosis I -
Prophase I
Metaphase I
Anaphase I
Telophase I

Meiosis II -
Prophase II
Metaphase II
Anaphase II
Teleophase II

Question 3

What is synapsis?

Answer 3

It is the process when each chromosome pairs up with a binds to its corresponding homologous chromosome and forming a tetrad (four sister chromatids in a pair of homologous chromosomes)

Question 4

What are genes?

Answer 4

Genetic information inherited from each parent

Question 5

What are alleles?

Answer 5

Different version of the same gene on each chromosome

Question 6

What occurs during prophase I?

Answer 6

Synapsis occurs as well as any potential crossing over. After, the nuclear membrane disappears, the centrioles move to opposite ends of the cell, and spindle fibers fan out from them

Question 7

What occurs during metaphase I?

Answer 7

The homologous chromosomes line up at the equator and attach to spindle fibers from opposite poles

Question 8

What occurs during anaphase I?

Answer 8

The spindle fibers separate the homologous chromosomes and pull them to opposite poles of the cell

Question 9

What occurs during telophase I?

Answer 9

One chromosome from each homologous pair are at separate poles (each chromosome still consists of sister chromatids) The spindle fibers disappear and the nuclear membrane reforms around the chromosomes and cytokinesis occurs

Question 10

What is cytokinesis?

Question 11

What is the product of Meiosis I?

Answer 11

two haploid daughter cells (each cells contains one set of homologous chromosomes consisting of paired sister chromatids

Question 12

What does haploid mean?

Answer 12

1 set of chromosomes in each daughter cell and do not contain homologous pairs

Question 13

What does diploid mean?

Answer 13

2 sets of chromosomes in each daughter cell and contain homologous pairs

Question 14

Does DNA replicate before Meiosis II begins?

Answer 14

No

Question 15

What occurs during prophase II?

Answer 15

The nuclear membrane disappear and spindle fibers fan out from the two pairs of centrioles

Question 16

What occurs during metaphase II?

Answer 16

The chromosomes in each cell line up at the equator and attach to spindle fibers from both poles

Question 17

What occurs during anaphase II?

Answer 17

The sister chromatids of each chromosome separate and move to opposite poles (after the sister chromatids separate theyre called chromosomes)

Question 18

What occurs during telophase II?

Answer 18

The spindle fibers disappear the nuclear membranes reform and cytokinesis occurs in both cells (creating 4)

Question 19

What is the result of meiosis II?

Answer 19

4 genetically different haploid daughter cells

Question 20

What does meiosis begin with?

Answer 20

a diploid cell

Question 21

What are the phases of mitosis?

Answer 21

interphase
Prophase
prometaphase
metaphase
anaphase
telophase -> cytokinesis

Question 22

What is the product of mitosis?

Answer 22

Two identical daughter cells (with all the genetic information pertaining to that organism)

Question 23

What is in the M phase (cell division) of the cell cycle?

Answer 23

Mitosis and cytokinesis

Question 24

What makes up the interphase of the cell cycle?

Answer 24

G1
S
G2

Question 25

What occurs during prophase?

Answer 25

Sister chromatids are condensed

Question 26

Draw a sister chromatid

Answer 26

.

Question 27

Draw a chromosome

Answer 27

.

Question 28

Draw a homologous chromosome

Answer 28

.

Question 29

What is a centromere?

Answer 29

Region of DNA where sister chromatids are joined

Question 30

What is different in the results of mitosis vs meiosis?

Answer 30

Mitosis results in 2 diploid daughter cells Meiosis results in 4 haploid daughter cells

Question 31

Sister chromatids only appear after when?

Answer 31

After DNA replication in S phase

Question 32

Draw tetrad of homologous chromosomes

Answer 32

.

Question 33

When are sister chromatids separated

Answer 33

During mitosis and meiosis II

Question 34

When are homologous chromosomes separated

Answer 34

During meiosis II

Question 35

What is independent assortment?

Answer 35

Can pass down either the egg parent's or sperm parent's versions (alleles) of each chromosome

Question 36

What is a tetrad?

Answer 36

a set of 4 sister chromatids consisting of the pair of duplicated homologous chromosomes

Question 37

What are the checkpoints in the cell cycle?

Answer 37

cell pauses to assess for mistakes and environment conditions to determine if the cycle can continue G1 checkpoint - if passes cell continues to S phase and divides its DNA G2 checkpoint - if passes, cell enter mitosis M checkpoint - if passes, all sister chromatids are attached to microtubules and cell completes mitosis

Question 38

What is cell division in prokaryotes?

Answer 38

Binary fission

Question 39

Where does DNA replication occur?

Answer 39

In S phase

Question 40

What are kinetochores?

Answer 40

Protein found at the centromere that binds to the spindle microtubles

Question 41

What are homologous chromosomes NOT?

Answer 41

They are not literal copies. They code for the same genes but carry different alleles of those genes

Question 42

Law of independent assortment

Answer 42

alleles of genes on non-homologous chromosomes assort independently into gametes

Question 43

Law of segregation

Answer 43

the 2 alleles for each gene separate into different gametes

Question 44

What is nondisjunction?

Answer 44

all daughter cells will have an atypical chromosome number (2 will have too many and 2 will have too few)

Question 45

What is aneuploidy?

Answer 45

atypical # of chromosomes in a gamete

Question 46

What is polyploidy?

Answer 46

more than 2 full sets of homologous chromosomes in a cell

Question 47

Why did Mendel study peas?

Answer 47

They had controlled mating, distinct heritable characters, and true-breeding varieties

Question 48

What is a genotype?

Answer 48

the genetic make-up, or set of alleles, for a particular gene (e.g. "PP" for purple flowers)

Question 49

What is a phenotype?

Answer 49

a collection of characters that are observable physical and physiological features of an organism, determined by its genetic make-up

Question 50

What does it mean to be homozygous?

Answer 50

1 version of the characteristic/gene is passed down and can be either dominant or recessive alleles

Question 51

What was Mendel's blending hypothesis?

Answer 51

Genetic material from parents blend in offspring

Question 52

What was Mendel's particulate hypothesis?

Answer 52

Parents pass on discrete heritable units to offspring

Question 53

Whats concept 1 of inheritance?

Answer 53

Alternative versions of genes account for variations in inherited characters

Question 54

What is concept 2 of inheritance?

Answer 54

An organism inherits 1 allele from each parent for each trait

Question 55

What is concept 3 of inheritance?

Answer 55

if 2 alleles at a locus differ, then the dominant allele determines appearance

Question 56

What is concept 4 of inheritance?

Answer 56

the 2 alleles segregate during gamete formation and end up in different gametes

Question 57

P generation

Answer 57

plants were true-breeding

Question 58

What does true-breeding mean?

Answer 58

When self-pollinated plants will always produce offspring that has the exact same phenotype as the P generation parent

Question 59

F1 generation

Answer 59

crossed 2 different true-breeding plants from the P generation

Question 60

F2 generation

Answer 60

self-pollinated F1 generation plants

Question 61

what is complete dominance?

Answer 61

in hybrids, 1 trait masks the other

Question 62

what is incomplete dominance?

Answer 62

in hybrids, the phenotype blends the two inherited traits

Question 63

what is codominance?

Answer 63

in hybrids, all inherited traits are shown in the phenotype

Question 64

Linked genes

Answer 64

Found on the same chromosome and since they are so close together crossing over is unlikely to separate them