Chapter 13 Meiosis And Sexual Life Cycle

Question 1

What do children inherit from their parents?

Answer 1

Just the DNA

Question 2

Transformation of traits from one generation to the next

Answer 2

Heredity

Question 3

Same trait but expressed differently. Ex. Eye color

Similar characteristics but not identical

Answer 3

Variation

Question 4

…..

Answer 4

Genetics

Question 5

Basic units of heredity

Made up of segments of DNA

Answer 5

Genes

Question 6

Gametes

Answer 6

Sperm and egg

Question 7

?The location for a specific trait?

Answer 7

Gene locus

Question 8

Most DNA is packed into ______________

Answer 8

Chromosomes

Question 9

Human somatic cells have _____ pairs of chromosomes

Answer 9

23

Question 10

Homologous chromosome pairs are the same __________ and _____________

Answer 10

Length and centromere placement

Question 11

Homologous chromosome pairs carry genes controlling the ________ inherited characters

Ex eye close

Answer 11

Same

Question 12

Humans have _____ set of sex chromosomes and _____ pairs of autosome chromosomes

Answer 12

1, 22

Question 13

2n is ….

Answer 13

Diploid -two sets

2n= 46 chromosomes total

Question 14

n is …..

Answer 14

Haploid

Single set of chromosomes

n=23

Question 15

Zygote…

Answer 15

One set of chromosomes from each parent

I cell

Question 16

Each replicated chromosome consists of …..

Answer 16

Two identical sister chromatids

Question 17

Meiosis starts with a _________ cell and ends with _________ cells

Answer 17

Diploid, haploid

Question 18

Meiosis results in four daughter cells with only ____ as many chromosomes as the parent cell

Answer 18

Half

Question 19

I’m meiosis 1 ____________ chromosomes separate and in meiosis 2 ____________ spectate

Answer 19

Homologous, sister

Question 20

Two key differences from mitosis to meiosis

Answer 20

• homologous pairs form a bivalent or tetrad

- crossing over

Question 21

Meiosis 1 and meiosis 2

Answer 21

Meiosis 1 (reductions division): homologous pair up and separate, resulting in two haploid daughter cells with replicated chromosomes

Meiosis 2 (equational division) sister chromatids separate

Question 22

What is the spot on a chromosome called where crossing over happens?

Answer 22

Chiasma

Question 23

Physical exchange between chromosomes prices of the crossing bivalent

Answer 23

Crossing over

Question 24

What phase does crossing over take place?

Answer 24

Prophase 1

Question 25

After interphase the sister chromatids are held together by proteins called

Answer 25

Cohesions

Question 26

A zipper like structure called the ________________ holds the homologs together tightly

Answer 26

Synaptoneal complex

Question 27

In meiosis are sister chromatids identical after crossing over takes place?

Answer 27

No

Question 28

Meiosis 1

Answer 28

Homologoues line up side by side at the equator- synapsis When pairs spectate, each daughter cell receives one member of the pair Cells are now haploid

Question 29

How the chromosomes line up in metaphase 1 is ___________

Answer 29

Random

Question 30

I’m prophase 1, replicated homologous chromosomes loosely pair up, aligned gene by gene (This happens prior to their segregation and crossing over)

Answer 30

Synapsis

Question 31

In prophase 1 Nuclear membrane ....... Replicated chromosomes...... What is formed?

Answer 31

Breaks down Condense Bivalents

Question 32

Non sister chromosomes reciprocally exchange DNA segments

Answer 32

Crossing over

Question 33

Each pair of chromosomes forms a __________, a group of four chromatids

Answer 33

Tetrad

Question 34

Each tetrad usually has one or more ___________, X-shaped regions where crossing over occurred

Answer 34

Chiasmata

Question 35

A spindle forms from each centrosome and spindle fibers attached to kinetochores and chromosomes This happens in what phase?

Answer 35

Prophase 1

Question 36

In what phase does the spindle apparatus complete, and the chromatids are attached to kinetochore microtubules Pairs of sister chromatids attached to ____ pole

Answer 36

Prometaphase 1 1

Question 37

In what phase are bivalents organized along metaphase plate as double row such that maternal or paternal members may be oriented toward either pole

Answer 37

Metaphase 1

Question 38

Homologous pairs separate maternal and paternal homologue into daughter cells independently of other pairs Promotes gentility diversity

Answer 38

Independent assortment

Question 39

In anaphase 1 segregation of _________________ occurs Connection between __________ break, but not the connections that hold ________________ together Each joined pair of chromatids migrates to one pole, and the homologous pair of chromatids moves to the opposite pole

Answer 39

Homologue Bivalent Sister chromatids

Question 40

In telophase 1 Sister chromatids ____________ And the nuclear membranes ___________

Answer 40

Decondense Reforms

Question 41

I’m the beginning of Telophase 1, each half of the cell has a ___________ set of chromosomes; each chromosome still consists of ______sister chromatids

Answer 41

Diploid | 2

Question 42

No chromosome replication occurs between the end meiosis I and the beginning of meiosis II because the chromosomes are already replicated True or false?

Answer 42

True

Question 43

In anaphase 1 | __________________ get pulled to opposite ends

Answer 43

Homologous chromosomes

Question 44

What is the period of time between meiosis 1 and meiosis II?

Answer 44

Interkinesis

Question 45

There is a S phase between meiosis 1 and meiosis 2 True or false?

Answer 45

False There is no S phase in between

Question 46

Sorting events of meiosis 2 are similar to those of _________

Answer 46

Mitosis

Question 47

Sister chromatids are separated during .....

Answer 47

Anaphase 2 Unlike anaphase 1

Question 48

In meiosis 2 each of the four daughter cells produced has the haploid chromosome number and each chromosome is composed of ___________

Answer 48

One chromatid

Question 49

Meiosis 2 is very similar to _______

Answer 49

Mitosis

Question 50

What happens in Prophase 2?

Answer 50

Spindle apparatus forms In late prophase, chromosomes (each still composed of two chromatids) move toward the metaphase plate

Question 51

Are the sister chromatids of each chromosomes in meiosis 2 genetically identical?

Answer 51

No, | because of crossing over In meiosis 1

Question 52

Metaphase 2

Answer 52

The sister chromatids are arranged at the metaphase plate (sister tids are not identical) The kinetochores of sister chromatids attach to microtubules extending from opposite poles

Question 53

In what phase do sister chromatids separate The sister chromatids of each chromosome now move as two newly individual chromosomes toward opposite poles

Answer 53

Anaphase 2

Question 54

Telophase 2....

Answer 54

The chromosomes arrive at opposite poles Nuclei form, and the chromosomes define decondensing

Question 55

At the end of meiosis, there are four daughter cells, each with a haploid set of _____________ chromosomes Each daughter cell is genetically __________ from the other and form the parent cell

Answer 55

Unreplicated Distinct

Question 56

What three mechanisms contribute to genetic variation?

Answer 56

- independent assortment of chromosomes - crossing over - random fertilization

Question 57

Crossing over begins very early in _______________, as homologous chromosomes pair up gene by gene

Answer 57

Prophase 1

Question 58

Crossing over produces __________________, which combine DNA inherited form each parent

Answer 58

Recombinant chromosomes