1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kozerog [31]
3 years ago
10

The cross of an aa male and Aa female produced an offspring with the genotype AAa. Therefore, the resulting offspring has 3 copi

es of gene 1 (trisomy for Chromosome 1). At what stage during meiosis did the non-disjunction event occur and in which parent? Circle all of the answers that apply.
a) Paternal non-disjunction in Meiosis Ib) Maternal non-disjunction in Meiosis Ic) Paternal non-disjunction in Meiosis IId) Maternal non-disjunction in Meiosis II
Biology
1 answer:
creativ13 [48]3 years ago
4 0

Answer:

The correct answer is option d.

Explanation:

Based on the given question, the genotype of the male parent is aa, the genotype of the female parent is Aa, and the genotype of the offspring is AAa, showing trisomy characteristics. In the given case, the existence of two A chromosomes shows that the chromosomes non-disjunction at the time of gametogenesis have taken place in the female as she is the only one possessing A allele. Hence, it can be concluded that the disjunction is maternal in characteristic.  

The duplication of chromosomes takes place at the time of the S-phase of meiosis. Thus, after going through S-phase, the karyotype of the cell will be AAaa (maternal gametogenesis), this set of the chromosome is termed as homologous pair, and the pair of AA or aa is termed as sister chromatids.  

The meiotic disjunction takes place in two phases. First, in meiosis I disjunction, in this separation of homologous chromosomes takes place, that is, the maternal cell AAaa get differentiated into aa and AA daughter cells. Secondly, in meiosis II disjunction, the separation of sister chromatids takes place into two independent chromosomes, that is, the formation of two cells each comprising chromosome A from the AA cell and the formation of two cells each with chromosome a from the aa cell.  

Thus, the phenomenon of non-disjunction would have taken place at the time of meiosis II in the case of a female gamete to exhibit two A chromosomes. Hence, the correct answer is option d.  

You might be interested in
Are sexual dissatisfaction and sexual abuse associated with obesity ? a population-based study
disa [49]
Hi! Can you please make your question clearer ?
7 0
3 years ago
Suppose you are an astronomer, and a child asks you to explain how long it takes light to travel through space. In your own word
Aleonysh [2.5K]
Ok so I would start by saying that light has a maximum speed, then explain that because space is so big we measure it's distance in light years and which means how light travels in a year at 186,282 miles per second Put that in perspective my saying If you could travel at the speed of light, you could go around the Earth 7.5 times in one second. Tell them Sunlight takes about 8 minutes 19 seconds to reach the Earth and that it can take millions or more light years for more distance stars light to reach our telescopes .
6 0
3 years ago
Proteins are
pishuonlain [190]
<span>B. converted from nucleic acids to amino acids in the nucleolus.
</span>
4 0
3 years ago
Read 2 more answers
The medical term meaning state of complete knowledge (identifying a disease) is:
miv72 [106K]
The medical term is DIAGNOSIS.
Diagnosis is a medical term which refers to the process of determining the disease condition that a patient is suffering from. Accurate diagnosis is made by examining the symptoms of the disease that the patient exhibits. Treatment can only be started after correct diagnosis has been made.
4 0
3 years ago
Why is stem cell research important within the field of medicine?
Stella [2.4K]
Researchers and doctors hope stem cell studies can help to increase understanding of how diseases occur, and to better understand how diseases and conditions develop.
5 0
2 years ago
Other questions:
  • The energy required for the cells to grow and undergo mitosis comes from which source?
    7·1 answer
  • Which word a synonym for demish
    11·1 answer
  • How would you determine whether a colony was a contaminant on a streak plate?
    5·1 answer
  • Various pieces of safety
    10·2 answers
  • Mouth guards protect what part of the body from blows sustained during physical activity
    8·1 answer
  • What type of protist is heterotrophic and includes species whose cells can come together to form a slug that moves to a new habi
    6·1 answer
  • What is the nature of chromosomes that align themselves on the metaphase plate in metaphase I?
    14·1 answer
  • In what stage does DNA synthesis occur? And what gets produced?
    11·2 answers
  • True or False? Animal cells are found in animals and humans.<br> A: True<br> B: False
    6·2 answers
  • Why mesophyll cell is considered as parenchyma cell​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!