× Didn't find what you were looking for? Ask a question
  
  
Top Posters
Since Sunday
26
14
o
10
j
7
s
7
R
7
e
6
6
b
6
f
6
s
6
j
5
New Topic  
Anonymous Carolina Castillo2
wrote...
A month ago
1) Use the following information to answer the next two questions.

Nondisjunction is an error in meiosis that results in non-separation of chromosomes during anaphase. Nondisjunction can occur during anaphase I or anaphase II of meiosis.


A) Which of the following correctly describes the gametes that will form as a result of nondisjunction during anaphase II in a human male?

a. Two sperm with 24 chromosomes and two sperm with 22 chromosomes

b. Two sperm with 23 chromosomes, one sperm with 22 chromosomes, and one sperm with 24 chromosomes

c. Four sperm with 24 chromosomes

d. Four sperm with 22 chromosomes




B) Which of the following statements is true?

a. More gametes will be affected if nondisjunction occurs during anaphase II than if nondisjunction occurs during anaphase I.

b. More gametes will be affected if nondisjunction occurs during anaphase I than if nondisjunction occurs during anaphase II.

c. Nondisjunction during anaphase I or anaphase II will have no effect on the gametes formed.

d. Nondisjunction during anaphase I or anaphase II will have the same effect.












2) Oogenesis involves germ cells in the ovary undergoing meiosis to produce a functional ovum at the end of the process.

Which of the following cells is penetrated by a sperm cell during the process of fertilization?

a. Oogonia

b. Secondary oocyte

c. Primary oocyte

d. Ovum






3) SEE IMAGE ATTACHED

Use the following information to answer the next two questions.

Basidiomycota is a division of the Kingdom Fungi. They include groups such as mushrooms, and reproduce sexually through the formation of cells called basidia.

A) Which of the following rows identifies Process 1 and Process 3 in the life cycle shown in the diagram?

a.    Process 1                        Process 3
       Meiosis                               Mitosis

b.   Process 1                          Process 3
        Mitosis                                Meiosis

c.   Process 1                           Process 3
      Meiosis                                 Meiosis

d.   Process 1                           Process 3
       Mitosis                                   Mitosis




B) Indicate the ploidy for each of the following cells indicated on the life cycle diagram above.   
Haploid = 1
Diploid = 2

zygote               Answer
 

basidiospores                 Answer
 

basidium with four nuclei                Answer
 
 
mycelia                           Answer










4) The giant panda has a diploid number of 42, which includes a pair of sex chromosomes that is analogous to human sex chromosomes (X and Y).

The karyotype of a male panda of the giant panda species would show Answer pairs of homologous autosomes and one pair of Answer sex chromosomes.

1) possible answers: 20 , 21 , 40 ,41
2) possible answer: homologous,   non- homologous.





5) Why is parthenogenesis in bees considered to be a form of asexual reproduction?

a. The haploid male bees were made through the process of meiosis, so they are identical to the parent egg cell.

b. The male drone develops from a haploid egg. Fertilization is not part of the process to make a male drone.

c. The formation of the original haploid cell was achieved using binary fission.

d. Although genetic material is transferred from one cell to another using conjugation, the resulting cells will be identical to each other.









6) see 2 image attached

Determine whether the structure in the life cycle of a moss is haploid or diploid and determine the process used to make the structure.

1 - Haploid
2 - Diploid


A - Mitosis
B - Meiosis
C - Fertilization

Gametophyte                Answer                                Answer

Sporophyte                   Answer                                Answer

Spore                           Answer                                 Answer

Zygote                         Answer                                  Answer

Egg                               Answer                                      Answer









7) Since the seedless bananas are triploid (3n ), and do not produce viable seeds for reproduction. To grow more seedless banana plants, farmers take a side shoot and replant it.

This type of reproduction is asexual because

a. meiosis does not occur.

b. budding does not occur.

c. binary fission does not occur.

d. mitosis does not occur.





8) see 3 image attached

Use the following information to answer the next three questions.

The diagram below illustrates the lifecycle of the parasite - Toxoplasma gondii.  This single celled organism causes the disease, Toxoplasmosis, which can be transferred to humans when cleaning out litter boxes.

A) Which of the following rows correctly identifies the processes 1, 2, and 3 numbered above?

a.   Process 1                Process 2                   Process 3
      Meiosis                      Mitosis                      Fertilization

b.   Process 1                 Process 2                    Process 3
      Meiosis                  Fertilization                      Mitosis

c.  Process 1                Process 2                      Process 3
   Fertilization                 Mitosis                        Meiosis

d.  Process 1                Process 2                       Process 3
     Mitosis                    Fertilization                       Meiosis





B) What is the ploidy of the zygote during the life cycle of Toxoplasma gondii?

a. 2n

b. 3n

c. 4n

d. 1n






C) The haploid genome of Toxoplasma gondii has 14 chromosomes. When an oocyst changes into a sporozoite, its nucleus contains

a. 28 chromosomes

b. 14 chromosomes

c. 7 chromosomes

d. 42 chromosomes

Attached file(s)
Thumbnail(s):
You must login or register to gain access to these attachments.
Read 97 times
2 Replies

Related Topics

Replies
Anonymous
wrote...
A month ago
#1

Part A

Meiosis include meiosis I and II, where two daughter cells with half chromosome number are produced from the parent cell in meiosis I, and then these two daughter cells divide to give rise to two cells each with equal number of chromosomes as of the two daughter cells after meiosis I. Hence, finally four cells or gametes are produced with half the number of chromosomes than the parent cell. Disjunction is a phenomenon where the homologous chromosomes separate from each other in the anaphase to go to the opposite poles. If this does not happen, the two chromosomes will go to one pole together and there will be no chromosome of that pair on the opposite pole. This is called non disjunction.

Hence, due to nondisjunction, there will be one extra chromosome in one cell and in other cell one less chromosome.

Here, a cell with 46 chromosomes will undergo meiosis I to give two cells with 23 chromosomes each, if there is no nondisjunction. These two cells will undergo meiosis II, but since nondisjunction is there in anaphase II of the meiosis II, the sister chromatids in a chromosome fail to separate and go to one pole instead of each sister chromatid to each pole.

Therefore the cells (gametes: sperm) produced will have unequal number of chromosomes, one with 22 and one with 24.

Option (B) is correct.

Part B

Nondisjunction is a process which causes failure in the separation of homologous chromosome or sister chromatids during meiosis. Now, we have to see when if this phenomenon occurs, causes more severe effects or does not cause them at all.

When nondisjunction occurs in anaphase I of meiosis I, all 4 gametes are affected; two of them do not receive the chromosome and other two receive two copies of the chromosome each.

On the other hand, when nondisjunction occurs in anaphase II of meiosis II, two gametes are formed as normal, one gets no chromosome and other gets two copies of chromosome.

It means that nondisjunction in anaphase I of meiosis I produces more affected gametes as compared to anaphase II of meiosis II.

Hence, the correct option is (B).

#2

Secondary oocyte - Correct

The secondary oocyte is penetrated by a sperm cell during the process of fertilization which results in the formation of the zygote. Hence this is the correct answer.

Primary oocyte - Incorrect

The secondary oocyte is penetrated by a sperm cell during the process of fertilization which results in the formation of the zygote. Hence this option is incorrect.

Oogonia - Incorrect

The secondary oocyte is penetrated by a sperm cell during the process of fertilization which results in the formation of the zygote. Hence this option is incorrect.

Ovum - Incorrect

The secondary oocyte is penetrated by a sperm cell during the process of fertilization which results in the formation of the zygote. Hence this option is incorrect.

Maximum of two questions per thread. Thanks! Slight Smile
Anonymous Author
wrote...
A month ago
thanks but can you help with the rest please
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  211 People Browsing
 245 Signed Up Today
Related Images
  
 4846
  
 698
  
 155
Your Opinion
Who's your favorite biologist?
Votes: 423

Previous poll results: Do you believe in global warming?