biology honor 2014-2015 name: ms. qotoj packet #10...

Biology Honor

Name:

2014-2015

PACKET #10 M s . Q o t o j

Unit 5: Reproduction and Heredity, Part 1: Meiosis and Human Reproduction Objectives:

Sexual Reproduction

1. Compare haploid (n) and diploid cells (2n) (12.2).

2. Differentiate between homologous chromosomes, autosomes*, and sex chromosomes (12.2).

3. Differentiate between somatic cells and gametes (12.2).

Meiosis (12.3) 4. Draw and describe each stage of meiosis.

5. Explain how variation in offspring is created through independent assortment*, crossing-over, and random

fertilization*.

6. Explain how the purpose of meiosis differs from that of mitosis.

7. Draw and describe how meiosis creates gametes (4 sperm cells in $, 1 egg cell in $).

8. Describe some anomalies associated with meiosis, including nondisjunction, trisomy, and monosomy

Human Sexual Reproduction (12.6-12.10)

11. Identify female reproductive structures on a diagram and describe the function of each (12.7).

12. Identify male reproductive structures on a diagram and describe the function of each (12.8).

13. Describe gamete development in males (12.8).

14. Describe gamete development in females and the stages of the menstrual cycle, including the identity and roles of the hormones involved (12.7).

15. Describe some anomalies associated with ovulation and fertilization, including monozygotic twins, dizygotic twins, and other multiple births (supplementary reading).

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Biology Honor

Meiosis Prophase I Metaphase I . Anaphase I Telophase I Prophase I I Metaphase I I Anaphase I I Telophase I I Variation Independent assortment Crossing over Random fertilization Karyotype Nondisjunction Monosomy Trisomy Down syndrome Turner syndrome Oogenesis Spermatogenesis Diploid (2N)

2014-2015

Haploid (N) Immature egg or sperm Mature egg or sperm Autosome Sex chromosomes (XX or XY) Somatic cell Gamete Zygote Ovum (plural = ova) Ovary Epididymis Follicle Vas deferens Ovulation Oocyte Urethra Spermatogenesis Polar bodies Seminal vesicles

Oogenesis

Corpus Luteum Prostate Fallopian Tube (oviduct) Penis Ovarian cycle Uterus Menstruation Endometrium Ejaculation Cervix Semen Vagina Fertilization Zygote Testes Gestation Scrotum Placenta

Seminiferous tubules

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Biology Honor 2014-2015

Meiosis How does sexual reproduction lead to genetic variation?

Why? Cells reproduce through mitosis to make exact copies of the original cell. This is done for growth and repair. Sexually-reproducing organisms have a second form of cell division that produces reproductive cells with half the number of chromosomes. This process is called meiosis, and without it, humans, oak trees, beetles, and all other sexually-reproducing organisms would be vastly different than they are today.

Model 1 - Meiosis I

1. According to Model 1, in what type of organs are the cells that enter meiosis I found?

Sex mtxU\ CVane^ jw&ti 2. Considering wnat you already know about mitosis in cells, what event must take place during

interphase before a cell proceeds to division?

3


3. "What two structures make up a single replicated chromosome?

Svsvor chromatids (and aiHrorywt) 4. In Model 1, how many replicated chromosomes does the cell contain during prophase?

4 Read This! Alleles are alternative forms of the same gene. For example, gene A may contain the information for fur color. One allele "A" may result in white fur, while the alternative allele "a" may result in black fur. Homologous chromosomes are chromosomes that contain the same genes, although each chromosome in the homologous pair may have different alleles.

5. At which stage in meiosis I do the pairs of homologous chromosomes come together?

UK - I 6. Once the chromosomes have formed a pair, what are they called?

7- At the end of meiosis I , two cells have been produced. How many replicated chromosomes are in each of these cells? ~

ol

8. Cells with a full set of chromosomes are referred to as diploid or 2a, whereas ceils with half the chromosomes are haploid or a. At which stage(s) of meiosis I are the cells diploid and at which stage(s) are they haploid?

dxfi\G\d • prophase -» anaphatf.

% 9. Which of the statements below correaly describes the relationship between the cells at the end of telophase I and the original cell?

a. The new cells have one copy of all of die genetic information in the original cell.

b. The new cells have two copies of all of die genetic information in the original cell.

c. The new cells have one copy of half of the genetic information in the original cell.

^?)The new cells have two copies of half of the genetic information in the original cell.

'"%10. Considering the genetic makeup of the homologous pairs, will the cells at the end of telophase I be genetically identical to each other?

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Biology Honor

Model 2 - Meiosis I I

2014-2015

Two cells from Meiosis I in Prophase II

Metaphase II Anaphase II

11. According to Model 2, where did each of the cells come from that started meiosis II?

12. In meiosis I , during anaphase I , which structures separated—homologous chromosomes or sister

chromatids? ^ ^ ( ^ j c K v W l O S W K f i A

13. In meiosis I I , during anaphase I I , which structures separated—homologous chromosomes or sister chromatids? , . . t * .

14. At the end of the meiosis I I are four daughter cells. Are they haploid or diploid? Explain your

answer in a complete sentence.

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15. Which of the statements below correctly describes the relationship between the cells at the end of meiosis I I and the original cell?

a. The new cells have one copy of all of the genetic information in the original cell.

b. The new cells have two copies of all of die genetic information in the original cell. / / " " X

( c.J The new cells have one copy of half of the genetic information in the original cell.

d. The new cells have two copies of half of the genetic information in the original cell.

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Biology Honor

Model 3 — Gametogenesis and Fertilization (Human)

Males Females

Secondary spermatocyte (end of meiosis I)

2014-2015

Spermatids (end of meiosis II)

Mature sperm

Secondary oocyte (end of meiosis I)

Oocyte proceeds to meiosis I I

Polar body eventually degenerates

Zygote with half its chromosmes from the female (maternal) and half from the male (paternal)

16. According to Model 3, what is the name given to the cells produced at the end of meiosis I in

17. What is the name given to the cells produced at the end of meiosis I in females?

StcmMiAj oocufc 18. Refer to Model 3. ^

a. At the end of meiosis I I in males, what cells are produced?

^ernncuhcls

b. What do these cells (from the previous question) eventually become?

19. Before fertilization, what happens to the secondarv oocyte? . . a

20. During fertilization which two cells come together? Be specific in your answer. /

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21. During meiosis I I , the secondary oocyte divides unevenly, with one cell (the ovum) receiving half of the chromosomes and nearly all the cytoplasm and organelles, while the other cell, the polar body, is much smaller and eventually degenerates. "With your group, propose an explanation to explain why the secondary oocyte divides in this way.

upon ^ p ^ L k d i m j } 5 n ai uM^ ?M:t ,MMjt \tfMr\

Ja 0 rti»n riAoA/i (J

22. What is the ploidy of the zygote produced by fertilization—haploid or diploid?

dxpietd

*%23. What would the ploidy of the zygote be i f egg and sperm were produced by mitosis rather than meiosis? How would this affect the ploidy of each successive generation?

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'-%24. With your group write a statement to explain the origin of the chromosomes found in the zygote. Your statement must include the term homologous pair.

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OhffVmo^orn^ of >&ach iUr^/ iO\^U^ j-\x^dkM

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Biology Honor

Extension Questions

Model 4 — Crossover of DNA in Chromosomes

2014-2015

Chiasma

Homologous pair of chromosomes (tetrad) during Prophase I

Recombinant chromatids

25. At which stage of meiosis are the chromosomes in Model 4?

26. When the chromosomes come together as homologous pairs, the arms of the sister chromatids may cross over.

a. What are these crossover points called?

b. Describe what happens to the chromatids during crossover.

^^m^Msk aWifcticU m^wN^L w m t i s 27. What phrase is used to describe the chromatids after crossing over takes place and the homolo

gous chromosomes separate?

28. Compare the recombinant chromatids with the original pair.

a. Are the genes on a recombinant chromatid the same as the original chromatid?

T b. Are the alleles on a recombinant chromatid the same as the original chromatid?

VvO.

Biology Honor

Model 5 — Genetic Variation

2014-2015

OR

Early Prophase I

Late Prophase I

Late Teloph

29. Model 5 is a condensed version of meiosis I . Notice the tsvo possible arrangements of chromosomes in late prophase I . Considering what you know about DNA replication and meiosis, is either arrangement equally likely during the formation of tetrads in late prophase I? Explain.

j#A. x MdmAm vokicX GMmw^nM of mch (pair u fws \\^\o UDlu'ch cell

30. I f theje were three sets of homologous chromosomes in the cell in Model 5, how many possible arrangements would there be for the tetrads in late prophase I?

Read This! a 3 . D

When homologous chromosome pairs align on the spindle during metaphase I die orientation of one pair is independent of the orientation of any other pair. This is known as independent assortment. Humans have 46 chromosomes, arranged as 23 pairs. During metaphase I each pair lines up independently, which results in 2 2 3 possible combinations.

31. With your group, calculate the number of possible genetic combinations due to independent assortment.

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9


32. As a group, choose one set of daughter cells in late telophase I from Model 5. Imagine that those cells now undergo meiosis I I . Draw at least four resulting haploid cells that could result.

33. Meiosis and sexual reproduction each lead to variation in the genetic make-up of every person. Wi th your group, explain how meiotic events, as well as the random fertilization of eggs and sperm, together lead to this genetic variation.

5/12/15

W e h a v e p a i r s o f c h r o m o s o m e s i n o u r c e l l s

• O n e c o p y o f e a c h c h r o m o s o m e f r o m m o m ; o n e f r o m d a d .

O These pa i r s a r e s a i d t o b e h a n i c i o a o i . i s ; f h e y c o n t a i n i h e

s a m e g e n e s a i s p e c i f i c l o c i .

T h e r e m a y b e d i f f e r e n i a l l e l e s [vers ions} o f a s i n g l e g e n e .

C h r o m o s o m e s c a n b e o r g a n i z e d i n l o a k o r / o i y p r - .

n 20

Human Karyotype

h I.'

,41'; i i

1 \> \\\> M

u V

1 ' ' 2 3 4 5

m i

t".l ?•:'

j f

\ ' n ii> i 1

I ' i

H\ 6 7 8 9 10 11 12

|l Iff Iff ill) M U <;', K

13 14 15 16 17 18 19

21 in 22 i!

X x Female

X Y Male

23 H o m o i o g o u s

pa i rs = 46

c h r o m o s o m e s in

e v e r y h u m a n c e i l .

22 pa i r s a r e

a u t o s o m e : ,

2 3 l d p a i r a r e

c h r o m o s o m e : ,

• XX fo r f e m a l e

• XY f o r m a l e

Gene loci Dominant allele

P^^ \ a -

/ ^

' .-: H

p a Recess ive allele

Genotype: PP aa Bb

Homozygous Homozygous Heterozygous for the for the dominant allele recessive allele

H o m o l o g o u s c h r o m o s o m e s m a y h a v e t h e s a m e o r d i f f e r e n i

a l l e l e s .

Human Karyotype

if »t 1

li

II

Ml!

u 20

If 2 3 4

U lit il 0 k 7 B 9 10 11

III II «8 M M 14 15 16 17

ff ft! 5

II 12

18 19

9 21

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22 0

X X Female

R e m e m b e r , y o u

i n h e r i t e d o n e o f

e a c h p a i r f r o m

m o m , t h e o t h e r

f r o m d a d .

W h e n y o u r b o d y

p r o d u c e s

g a m e t e s , i t w i l l

s h u f f l e t h e s e

c h r o m o s o m e s

a r o u n d t o p a s s

o n e o f e a c h o n t o

y o u r o f f s p r i n g .

How?7v''.-k>5H!

M e i o s i s : C e l l d i v i s i o n i h a l p r o d u c e s h a p l o i d ( n ) c e i l s

( g a m e t e s )

D N o h o m o l o g o u s c h r o m o s o m e pa i r s in h a p l o i d

W h y is m e i o s i s i m p o r t a n l ?

• S e x u a l r e p r o d u c t i o n

• G e n e i i c v a r i a t i o n a m o n g o f f s p r i n g

T w o d i v i s i o n s t a k e p l a c e

• Me ios i s 1 - s e p a r a t i o n o f

h o m o l o g o u s c h r o m o s o m e s . P i ,

M l , A , . T ,

O Me ios i s 2 - s e p a r a t i o n o f sister c h r o m a l i d s . P 2 , M j , A 3 , T 2 .

®(OX0)(fi> (

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Meiosis Results in Offspring Variation

3 M a j o r w a y s m e i o s i s is d i f f e r e n t f r o m m i t o s i s :

O C e i l d i v i d e s 2x, b u t o n l y r e p l i c a t e s D N A t x . Results in h a p l o i d

ce l l s .

O D is t r i bu tes r a n d o m m i x t u r e o f p a r e n t g e n e s ( i n d e p e n d e n t

assor t i f ve-rif}

n H o m o i o g o u s c h r o m o s o m e s p a i r u p d u r i n g l 1 ' ce l l - j -

H e r e , t h e y o f t e n e x c h a n g e g e n e s c t o s s l n g o*>e-r

m

p.

\

H o m o l o g u e s l i n e

u p . 2 p o s s i b l e

o r i e n t a t i o n s . 5 0 %

c h a n c e f o r . e a c h .

Th is is c a l l e d

i ndependen t a p a r t m e n t .

Q : H o w m a n y

d i f f e r e n t

c o m b i n a t i o n s

( g a m e t e s ) c a n a

c e l l w i t h 2 n = A

m a k e ?


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Biology Honor j 2014-2015 1. How many replicated chromosomes are pictured? I

2. How many homologous chromosome pairs are pictured? 0 4

3. How many different genes are pictured?

4. How many genes relate to hair texture?

5. Of the chromosomes present, how many were paternally-inherited?

6. Of the chromosomes present, how many were maternally-inherited? (yi

7. Did this person inherit the "normal" version of the hemoglobin gene from both paternal and maternal sides?

8. Did this person inherit the "normal" version of the p53 gene from both paternal and maternal sides?

9. What is the difference between the "normal" version of the hemoglobin gene, and the "abnormal" version of the hemoglobin gene? f lf l A iS ^ ( Q O j l UTtth QJT

10. What letter is used to abbreviate the "normal" version of the hemoglobin gene? . f t 11. What letter is used to abbreviate the "abnormal" version of the hemoglobin gene? ^

12. Do you think that this person will make "normal" hemoglobin proteins, or "abnormal" hemoglobin proteins? )u mink tn

13. Will this person have Sickle Cell Anemia? W ; ^iCJLij. Ql[\ HnRU£

14. This person has inherited "normal'Vnon-mutated p53 genes. So, when the cell divides in mitosis, each new cell will get two copies of the "normal" version of the p53 gene. Does this mean that ALL cells will have "normal" versions of the P53 gene? f\Q Explain . j U l ^ f j f l f l o ( \gP .

Mvm^ /n QpJA f t p , ^mnsanphGyx, /nrlmnKi&iWv)

15. There are three genes here relating to hair texture. Assume that all three genes weigh equally in terms of what the person will look like. So, this is an example of a "transcription unit," when multiple genes together determine the outcome or an appearance. Do you think that this person will have straight, wavy, curly, or very curly hair?

16. If there are 20,000 genes in a human genome, approximately how many genes are present on each homologous pair of chromosomes? fyYO (So this diagram clearly doesn't show enough genes on each homologous pair.)

17. What percentage of genes do human share with one another? (6b

18. What percentage of A/C/G/T sequence do humans share with one another?

19. As we have learned before, out of the 3,000,000,000 "letters" in the human genome, the majority of A/C/G/T sequences are considered "noncoding," as they do not directly code for proteins made by the cells' ribosomes. Based on this diagram, identify three different locations of "noncoding" A/C/G/T sequences.

Biology Honor

Crossing Over Practice:

2014-2015

Paired chromosomes at the beg inn ing Chromosomes af ter crossing over of meisois are analogous t o pairs of contain in fo rmat ion f r om maternal instruct ion manual pages. and paternal chromosomes.

The diagram below shows a pair of homologous chromosomes about to undergo chiasma formation during the first cell division in the process of meiosis. There are known crossover points along the length of the chromatids (same on all four chromatids shown in the diagram). In the prepared spaces below, draw

the gene sequences after crossing over has occ_-e: unrelated and separate occasions (it would be _ss-different coloured pens to represent the genes different chromosomes). See the diagrams on the as a guide.

Homologous chromosomes

a b c d e f g

a . b c d e f g

h i j k g r n n o . p ) -

h i j k I m n o p ) -

6

Chromatid 1

7 8 9*-

i 11

Chromatid 2

Possible knew-crossover poin:; on the chroma:1:

Chromatid 3

Chromatid 4

H I J K L M N O P

mum

1. Crossing over occurs at a single point between the chromosomes above.

(a) Draw the gene sequences for the four chromatids (on the right), after crossing over has occurred at crossover point: 2.

(b) List which genes have been exchanged with those on its homologue (neighbour chromosome):

Crossing over occurs at two points between the chromosomes above.

(a) Draw the gene sequences for the four chromatids (on the right), after crossing oyer has occurred between crossover points: 6 and 7.

(b) List which genes have been exchanged with those on its homologue (neighbour chromosome):

hxXMJLmm. T ' VI I , X

nop \ 2

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Biology Honor

Independent Assortment Practice:

2014-2015

P r e c w w i ceSis to j p e t m and ogi;<, hove 2 topic* of

« ,Kh «lwonxKOrr.« ~ that is, 2 full i c t i of

irulrucfson manua l pog-et, ! from e*ch parent.

Sperm a/id -05.3 ooll< h-svi- eoly 1 full tut — 0

r a n d o m <0/iibirwilica of maternal a n d paternal

ircsUucfion manua l p.ig-ei.

In hum.j.-is, er.Vf 8 million

combln-aticm are

costibte.

Page 5 Pngo IS

Bltxtdtjro-up Eyt'~<olsf gtnt i t

P j q e 9

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gofH' frcrn mom

V Pago f5

(f 01 it morn

V Page 9

Olocdxjroup rjena Eyft•<&!<!,' genet

from rnrxn />Offl dfld

figu/o fi-4 E « h « g g a n d t p o n n It unit;ui:>, T h b Injure U M S tho I m t r u c i i c n inarvw.it analogy to show h e w .1

iinijU' n u n 6*n p p x I i K p on I ' lx inrxxjs tihttuv/ of tfMjrni, The w m c p r s x e t i of independent .Hsortmem r r t u h i

in t jnormtxn diver tity I n eg<n . n vwl l . Tho t h a i J f c tho l e u r c c of „i m-wi't t p c r n i « r i y 2 of ca<h chfOrno-

s i r r w — t r u t is. 2 fi-il < p p i « - of the artarwilion rrnmunJ-—1 set. iibtfi hit morn, the d O W from hit tf.td. W h e n 0

t j w m cell it p r o d u < . « J , it e » d t up wi th only 1 copy 0*1 e i i l i p.tge. Since C - K I U K O T i j produced ind.>{i«r>a*ntly.

the w t of p.iQO-, in c j t h t p c m wi-U bo s •jnifju.; t c r n b i t i j u o n o f "ho p-irjs-i lh.it tho r>vm inherited from hit

morn .j^.rj rt.td.

Biology Honor

Comparing Mitosis and Meiosis:

2014-2015

Mitosis Meiosis

Purpose of the process m a f o i k f i j u o cms Lcfwjddk

Location(s) in the human body where this process occurs

Are the products the same or different, as compared to one another?

&Mrf\t CdlS .

(art ^m^vriiyoecpitio^

Number of products formed? Q _ H

Number of rounds of division? i o?

Products are diploid or haploid? I f the original cell had 6 replicated chromosomes, this is how the cell would look in metaphase (refer to metaphase I for meiosis). You must use six different colors here, and you must write a caption beneath each picture (use terms like replicated chromosome, homologous chromosome, etc.). CMvwO^J^B a r e t t r u i

a r t Utrudl t f a r 4 U a i v l c * f

I f the original cell has 6 replicated chromosomes, this is how the cell would look in Metaphase I I of meiosis. Use different colors here! You must also write a caption below the picture.

N/A

C h r o m o s o m e s UAtu^

13

Biology Honor (^MVUOAU AW\A|V\

si a metagenesis la animal:

•••A \1 ' ^ - - f Spermatogonium 2M Oogonium

2014-2015

2M 5| fi '>

<spemi) \ _ - 'I Primary

- ) spermatocyte 2 N

Primar/ oocyte

FX

Secondary Secondary / I spermatocyte 'IN oocyte, *

y J

polar body ^ J

\ ? -y /

i Spermatids Ootid / ; - y \ r-

1 V

i 4 CHfftiiOnLiatiOil

f I \

Sperm Ovum f f

v

Second Polar bodies polar body

'g i t mojc/e*/

Spermatogenesis Class Notes:

-l+appead ^-testes

~ioo (vul\t(Msperm w M t ^ d a u

~W\eNfc-to ef\di(UjvvviS -Jar f \^ah(Y)

CO-'

Oogenesis Class Notes:

- t f a p p t f i s m o v a r i e s

6IM p r i i r m ^ m o o a i i e a > o t w u i e &

ID meiosi's ~u£ (Caused »h rretor

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Oogenesis and Spermatogenesis Comparison Chart

Oogenesis Spermatogenesis

Meiosis or mitosis?

_ _ _ _ „ • • — — —

Purpose of the process ma)uL s p e r m

Location of the process teS+vs

Number of products formed

Number of products capable of participating in fertilization

Do the products need to develop further after meiosis EE (before fertilization)?

1

no

¥

yes

Are the products equal in size? Explain. 3SWLU -po\aY bodies T

When during a person's lifetime does the process begin? When does the process complete?

5C<3in - b e f o r e birth

Are the primary oocytes or spermatocytes present at birth? yes

S j Xjf I f - -y-- V — o - „.is-r. -

WO

Produced via mitosis or meiosis?

Genetically unique or identical?

Diploid or haploid?

# of homologous chromosome pairs?

# o f chromosomes?

Immature eggs (primary oocytes) and immature sperm (primary spermatocytes)

1 3

Mature eggs and mature sperm

Uaflcad 0 23

15

5 / 1 3 / 1 5

Errors in Meiosis

Nondisjunction — failure of chromosome separation in anaphase I or II of meiosis P Anaphase I - homologues

don t separate • Anaphase II-sister

chromatids don't separate D Results in gametes with

abnormal numbers of . chromosomes

D (20% to 50% of miscarriages result from fertilization of gametes with abnormal numbers of chromosomes)

(X) / \

a

OBJ 19

"Nondisjunction

Meiosis II / \ K A

i9! • i i

Nondisjunction

Game too

i l l : i | i|

+1 n+1 n - \ n -1 n+1 n - 1

Number of chromosomas

n . + • ] - = . t r i s o m y ' -f • n - 1 - m o n o s o m y 1 j

OBJ 1£

Errors in Meiosis (cont.;

Nondisjunction of autosomes (non-sex chromosomes)

• Trisomy 21—Down syndrome 1 Effects include mental retardation, eyes that

slant upward, and heart defects It affects over 350,000 people in the United States alone and is the most common (1 in 800 live births) imbalance in the number of autosomes in people.

OBJ 19

Errors in Meiosis (cont.i

Nondisjunct ion of sex chromosomes

• Turner's syndrome (XO)

• Klinefelter^ syndrome (XXY)

• XYY males

1

Biology Honor

Nondisjunction, Trisomy & Monosomy How could a zygote (fertilized egg) have three 21st chromosomes (Down Syndrome)?

2014-2015

WoR: 1Wc W ^

NiOfWAL- ,

How could a zygote (fertilized egg) have one X and zero Y chromosomes (Turner Syndrome)?

WoH: 1Wc J l w U \t

Normal

Nondisjunction occurs on sex chromosomes

16

Biology Honor

Putting it all Together! 2014-2015

Use 4 different colors to show 4 different chromosomes in the cells from the paternal side. Then use 4 separate colors to show the chromosomes from the maternal side. Use size to distinguish between homologous pairs. So, in all, you will need 8 colors. Track these chromosomes (by using color) throughout the processes below. Ignore crossing over.

17


Meiosis practice (with a little mitosis, too)

1. The drawing on the right is of the sperm cell of a certain animal. The sperm cell has four chromosomes. a. Give the number of chromosomes in a stomach cell of the animal indicated. b. Make the diagram of the mature egg cell of this animal, showing the chromosomes.

c. Make a diagram of the zygote of this animal, showing the chromosomes.

d. Make a diagram of the 2-celled stage of this embryo, showing the chromosomes.

2. In a certain animal cell, the diploid number is 10. Give the number of chromosomes found in: -a mature sperm cell -a zygote -a mature egg cell -a skin cell

3. The following questions refer to the diagrams below

i r v.) I • ' i • :/ /

a. The cell indicated by the letter A is a . It is manufactured in the

b. The process that results in the formation of cell C is ,. Cell C is produced in the

c. The chromosome number in cells A and B is produced by the process of .

d. Cell C will immediately begin to .

e. The chromosome number of cell C is called _ _ , while that of cells A and B is called

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4. Label each of the following statements as being descriptive of prophase I , metaphase I , anaphase I , telophase I , prophase I I , metaphase I I , anaphase I I , or telophase I I of meiosis.

gametes fully formed sister chromatids split apart

. homologous chromosomes split apart homologous chromosomes line up two-by-two replicated chromosomes line up single file

5. Name the three processes whereby genetic diversity is increased. Describe two of these processes.

6. A donkey somatic (body) cell contains 62 chromosomes, and a horse somatic cell contains 64 chromosomes. The donkey and horse can mate to produce a mule. However, a mule is sterile as mule cells cannot undergo meiosis. Explain why mitosis is normal in mule cells, but why the mixed set of chromosomes interferes with meiosis.

7. A micrograph of a dividing cell from a mouse showed 19 replicated chromosomes, each consisting of two chromatids. (Picture is shown below.) Could this picture have been taken in prophase I of meiosis? Why or why not? Could this picture have been taken in anaphase of mitosis? Why or why not? What about prophase I I of meiosis?

8. The diagram below represents metaphase I I of meiosis in a cell that had two pairs of homologous chromosomes. Draw a diagram showing how cells from this same (multicellular, sexually-reproducing) organism would look in metaphase of mitosis.

iy


3. Shown below is a cell that has just finished telophase of mitosis (including cytokinesis). In the boxes that follow, show how a cell would look (from the same organism) in each of the stages listed.

Metaphase I - Meiosis Anaphase I I - Meiosis Prophase - Mitosis

4. If the diploid number is 50, there are (how many?) homologous chromosome pairs.

5. If the diploid number is 30, there are (how many?) chromosomes per gamete.

6. If there are 40 replicated chromosomes at the beginning of meiosis, one would expect (how many?)

(replicated or unreplicated?) chromosomes per gamete at the end of meiosis. Each gamete has (what fraction?) of the DNA mass of the original cell entering meiosis (after interphase). Each gamete has . (what fraction?) of the genetic information of the original cell (after interphase).

7. At the end of mitosis, each daughter cell has (what fraction?) of the DNA mass of the original cell entering mitosis (after interphase). Each daughter cell has (what fraction?) of the genetic information of the original cell (after interphase).

8. Human somatic (body) cells have (how many?) chromosomes.

9. Human gametes have (how many?) chromosomes.

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Biology Honor

Figure 1: Female Reproductive Anatomy - side view

2014-2015

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biology honor 2014-2015 name: ms. qotoj packet #10...

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