Differentiate between 'ZZ' and 'XY' type of sex-determination mechanisms. - Biology


Differentiate between 'ZZ' and 'XY' type of sex-determination mechanisms.



The differences between ZZ and XY type of sex-determination mechanisms are listed below:

ZZ Sex-Determination Mechanism XY Sex-Determination Mechanism
In this type of chromosomal sex determination mechanism, the females are heterogametic, that is, they produce two types of gametes, while the males are homogametic. In this type of chromosomal sex determination mechanism, the males are heterogametic, that is, they produce two types of gametes, while the females are homogametic.
Here, the females produce two types of eggs (A+Z) and (A+W), while the males produce only one type of sperm (A+Z).​

Here, the males have an X chromosome and its counterpart Y chromosome, which is distinctly smaller. Hence, the males are XY. However, females have a pair of X chromosomes; therefore,  they are XX.

 Organisms that have the ZZ type of sex-determination mechanism are birds, fishes, some reptiles, etc.  Organisms that have the XY type of sex-determination mechanism are humans and Drosophila.
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2014-2015 (March) Delhi Set 3

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Explain sex determination in human beings.

Answer the following questions related to sex determination in human beings:
i. What is sex chromosome?
ii. How many pairs of chromosomes are present in human beings?
iii. How is the sex of the human offspring determined?
iv. Draw a diagram depicting sex determination in man.

If X chromosome is inherited from mother and Y from father, the offspring will be male.

Write the types of sex-determination mechanisms the following crosses show. Give an example of each type.
(i) Female XX with Male XO
(ii) Female ZW with Male ZZ

Differentiate between male and female heterogamety

Explain the mechanism of sex determination in birds.

Write notes on Sex determination in the unborn baby.

There are ................ pairs of chromosomes in the human being.

There are two sets of chromosomes in the zygote.

Explain the mechanism of 'sex determination' in birds. How does it differ from that of human beings?

The human animal which has an XY pair of chromosomes is called :
(a) male
(b) hybrid
(c) female
(d) doomed

In human males all the chromosomes are paired perfectly except one. This/these unpaired chromosomes is/are :
(i) large chromosome
(ii) small chromosome
(iii) Y chromosome
(iv) X chromosome

Name any two genetic in humans.

Among lion, tiger and domestic cat, al the three have the same number of 38 chromosomes, yet they have different appearances. How do you account for such differences?

Does the sex of the child depend on the father or it is just a matter of chance? Discuss 

A family consists of two parents and their five children and the pedigree chart below shows the inheritance of the trait colour blindness in them.  

Who is colour blind in the parents – the Father or the Mother?  

Why did T. H. Morgan select Drosophila melanogaster to study sex linked genes for his lab experiments ?

________ shows haplo-diploid type of sex-determination.

Choose the correct answer from the four options given below : 
In a human male, a sperm will contain : 

What determines the sex of a child in humans?

What do you understand by sex-linked inheritance?

Choose the correct answer:

Males have more chances of suffering from sex-linked disease because of ___________

Choose the correct answer:

A man can transfer his sex-linked gene to his ______________

Drone of the honeybees shows haploid number of chromosomes. Illustrate. 

In which livings, female decides the sex? Give two examples.

(a) How many pairs of autosomes and Paris of sex chromosomes are present in a human being?  
(b) Which chromosomes are present in Females? 
(c) Which chromosomes are present in Male? 
(d) How does sex determination take place in human beings? 

Answer the following question:
How is sex determined in human beings? Explain with the help of a diagram. 

Write a short note on sex determination in man.

Complete the following sentence with appropriate word:

______are the alternative forms of a gene producing different effects.

Explain the haplo-diploid method of sex determination in the honey bee.

How drones are produced in honey bees?

Explain the mechanism of sex determination in humans with a suitable chart.

Kavitha gave birth to a female baby. Her family members say that she can give birth to only female babies because of her family history. Is the statement given by her family members true? Justify your answer.

XO type of sex determination and XY type of sex determination are examples of ____________.

ZW-ZZ system of sex determination occurs in

Which of the following is incorrect regarding ZW-ZZ type of sex determination?

What is haplodiploidy?

Distinguish between heterogametic and homogametic sex determination systems.

What is Lyonisation?

Differentiate Intersexes from Supersexes.

What is male heterogamety?

Brief about female heterogamety.

Explain the mode of sex determination in honeybees.

How is sex determined in human beings?

How many ovum are formed when a diploid cell undergoes meiosis, during oogenesis?

Identify the female heterogamety from the chromosomal complements given below.

Read the following statements and select the correct option.

i. If sperm containing Y chromosome fertilizes the ovum, then diploid zygote is formed that grows into a male child.

ii. If sperm containing X chromosome fertilizes ovum, then diploid zygote is formed, that grows into a female child.

From the following which option correctly represents the normal genetic constitution of a ovum?

There are five daughters and no son in a family. It is because

Which type of sex determination is observed in honey bee?

Diploid larvae which get royal jelly as food develops into ____________ and other develops into workers (sterile females).

Identify the organism in which ZZ-ZW type of sex determination is observed.

Which of the following develops through parthenogene is?

Chromosomal constitution of normal human females can be written as ______.

The ‘X’ body of Henking was observed in ______.

Haplodiploidy is found in ______.

Grasshopper is an example of XO type of sex determination in which the males have ______.

In XO type of sex determination ______.

Which of the following combination of chromosome numbers represents the correct sex determination pattern in honey bees?

The number of pairs of sex chromosomes in the zygote of a human being is ______ 

A man with blood group A marries a woman having blood group O. What will be the blood group of the child?

Which of the following is an example of genetic variation?

The maleness of a child is determined by ______ 

If a normal cell of the human body contains 46 pairs of chromosomes then the numbers of chromosomes in a sex cell of a human being is most likely to be ______

Select the statements that describe characteristics of genes

  1. genes are specific sequence of bases in a DNA molecule
  2. a gene does not code for proteins
  3. in individuals of a given species, a specific gene is located on a particular chromosome
  4. each chromosome has only one gene

The belief that the mother is completely responsible for the sex of the child is wrong because the child

Structures present in a cell which is responsible for determination of the sex of a baby is

Fill the blank circles in figure and identify the sex of child A and B. 

Sex in honey bee is determined by ______.

The chromosomal constitution of a human female can be written as ______

Female heterogamy is shown by

In humans, males are heterogametic and females are homogametic. Explain. Are there any examples where males are homogametic and females heterogametic?

Does a male child inherit X chromosome from his father? Justify.

What is the probability of a girl or a boy being born into a family? Justify your answer.

What is sex determination? Explain the mechanism of sex determination in the case of birds.


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