$CATEGORY: Science - Khan Academy/9.Heredity & Evolution/9.Heredity & Evolution--Heredity

//Multiple Choice

In humans, the sex of a child is determined by which parent? {
    ~Mother
    =Father
    ~Both equally
    ~Neither
}

Which chromosome combination represents a male in humans? {
    ~XX
    =XY
    ~YY
    ~XO
}

What is the chromosome combination in a female human? {
    ~XY
    =XX
    ~XO
    ~YY
}

What determines the male sex in humans? {
    ~X chromosome from the mother
    ~X chromosome from the father
    =Y chromosome from the father
    ~Autosomes
}

How many sex chromosomes are present in a human gamete? {
    =1
    ~2
    ~23
    ~46
}

Which sex chromosome is absent in females? {
    ~X
    =Y
    ~Z
    ~W
}

In birds, which chromosome combination determines the female sex? {
    ~XX
    ~XY
    =ZW
    ~ZZ
}

What is the probability of a human child being male? {
    ~25%
    =50%
    ~75%
    ~100%
}

Which of the following organisms use the XY system for sex determination? {
    =Humans
    ~Birds
    ~Bees
    ~Reptiles
}

What is the role of autosomes in sex determination? {
    ~They directly determine sex.
    =They provide genetic information unrelated to sex.
    ~They code for the Y chromosome.
    ~They are absent in sex determination.
}

//True or False

In humans, the sex of a child is determined by the father. {T}

A human female has one X and one Y chromosome. {F}

The probability of a child being female is 50%. {T}

The Y chromosome is larger than the X chromosome. {F}

In birds, the male determines the sex of the offspring. {F}

Humans use the XY system for sex determination. {T}

In reptiles, temperature can influence sex determination. {T}

The X chromosome is present in both males and females. {T}

In bees, males develop from unfertilized eggs. {T}

All organisms use chromosomes to determine sex. {F}

//Fill in the blanks

The sex of a human child is determined by the ________ of the father. {
    ~X chromosome
    =Y chromosome
    ~Autosomes
}

In humans, the combination of ________ chromosomes determines a male child. {
    ~XX
    =XY
    ~YY
}

A female human has ________ sex chromosomes. {
    =XX
    ~XY
    ~XO
}

The probability of a child being female is ________. {
    ~25%
    =50%
    ~75%
}

The number of sex chromosomes in a human gamete is ________. {
    =1
    ~2
    ~23
}

The sex of a child in birds is determined by the ________. {
    ~Male
    =Female
    ~Both parents equally
}

In bees, sex is determined by the number of ________. {
    ~Autosomes
    =Chromosomes
    ~Genes
}

The Y chromosome is ________ in females. {
    ~Present
    =Absent
    ~Doubled
}

Sex determination in reptiles is often influenced by ________. {
    ~Chromosomes
    ~Genes
    =Temperature
}

In humans, the total number of sex chromosomes in a zygote is ________. {
    ~1
    =2
    ~23
}

//Numericals

In humans, how many chromosomes are present in a gamete? {
    ~46
    =23
    ~22
}

What is the probability of a child being male in humans? {
    ~25%
    =50%
    ~75%
}

How many sex chromosomes are present in a zygote? {
    ~1
    =2
    ~23
}

If a family has 4 children, what is the probability that all will be boys? {
    =6.25%
    ~12.5%
    ~25%
}

If a DNA sequence contains 30% adenine, what percentage of thymine does it have? {
    =30%
    ~20%
    ~40%
}

How many total chromosomes are present in a human somatic cell? {
    ~23
    =46
    ~92
}

If a male contributes a Y chromosome, what is the probability of the child being male? {
    ~0%
    ~50%
    =100%
}

In birds, what percentage of offspring inherit a Z chromosome from the father? {
    ~25%
    ~50%
    =100%
}

How many pairs of autosomes are present in a human cell? {
    =22
    ~23
    ~44
}

In haplodiploidy, how many chromosomes are present in a male bee? {
    =Haploid number
    ~Diploid number
    ~Triploid number
}

//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
=XX -> Female
=XY -> Male
=Y Chromosome -> Determines the male sex
=X Chromosome -> Common in both sexes
}


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