Tag: biology

Questions Related to biology

The instrument which measures wind velocity is

biology physical resources air and winds wind energy air as a natural resource

  1. Lactometer

  2. Anemometer

  3. Hydrometer

  4. Barometer

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Correct Option: B
Explanation:

Anemometer is the instrument used to measure wind velocity. Hydrometer measures specific gravity (or relative density) of liquids. Barometer is used to measure atmospheric pressure. Lactometer measures cream content of milk.

The instrument which measures wind velocity is

biology physical resources air and winds wind energy air as a natural resource

  1. Lactometer

  2. Anemometer

  3. Hydrometer

  4. Barometer

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Correct Option: B

As the air temperature increases, the air's capacity for water vapor:

biology physical resources air and winds wind energy air as a natural resource

  1. Increases

  2. Decreases

  3. Remains constant

  4. Is unrelated to air temperature and can either increase or decrease

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Correct Option: A

The earth's first atmosphere was composed primarily of:

biology physical resources air and winds wind energy air as a natural resource

  1. Carbon dioxide and water vapor

  2. Hydrogen and helium

  3. Oxygen and water vapor

  4. Argon and nitrogen

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Correct Option: B

Choose the correct answer from the alternatives given.


A couple has six daughters, What is the possibility of their having a girl next time?

biology mendel's law of inheritance determination of sex sex determination sex determination in humans

  1. 10%

  2. 50%

  3. 90%

  4. 100%

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Correct Option: B
Explanation:

The possibility of having a girl or boy child is equal Le., 50% as 50% male gametes are Y type and 50% are X type. Fusion of egg with X type sperm will produce a girl child. 

If the first seven children born to a particular pair of parents are all males, what is the probability that the eighth child will also be a male?

biology mendel's law of inheritance determination of sex sex determination sex determination in humans

  1. $\dfrac{1}{2}$

  2. $\dfrac{1}{4}$

  3. $\dfrac{1}{8}$

  4. $\dfrac{1}{16}$

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Correct Option: A
Explanation:
The sex of an individual depends on the combination of sex chromosomes in its cells, that is, the combination of X and Y chromosomes. An embryo with XX genotype would develop into a female, while an embryo with an XY would develop into a male. The mother has a genotype and would always produce gametes with an X chromosome. The father, however, would produce half the gametes having an X chromosome and half carrying a Y chromosome. The sex of the embryo in humans would hence depend on the chromosome present in the gamete of the father. For every child conceived, there is an equal probability of the child being a male or a female, as the gamete received from the father has a 50% chance of carrying an X chromosome and  50% chance of carrying a Y chromosome.
So, the correct answer is $\dfrac{1}{2}$

In human beings, the gametes from the .......... decides the sex of the baby.

biology mendel's law of inheritance determination of sex sex determination sex determination in humans

  1. Male parent

  2. Female parent

  3. Both A and B

  4. None of the above

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Correct Option: A
Explanation:
Sex is determined by two chromosomes, X and Y. A female is XX, a male is XY. Since women completely lack the Y chromosome, they always contribute an X chromosome to the baby. The sex is determined by whether the sperm that fertilizes the egg is carrying another X or a Y.
The generally accepted theory is that males determine the sex because males can donate both an X chromosome or Y chromosome, while females can only donate an X chromosome to their offspring, making their contribution constant and the male's contribution the variable which, under normal circumstances, determines the offspring's genetic sex.

A son inherits an X chromosome from 

biology mendel's law of inheritance determination of sex sex determination sex determination in humans

  1. Mother

  2. Father

  3. Both A and B

  4. Grandparents

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Correct Option: A
Explanation:
A child will inherit Y chromosome from father to become a boy. In human being, Y is the factor of maleness.
Male parent:  XY     x      Female parent: XX
Gametes:      X, Y            X
Offspring:     XX (Female child), XY  (Male child)

A child who inherits an Y chromosome from father will be a girl.

biology mendel's law of inheritance determination of sex sex determination sex determination in humans

  1. True

  2. False

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Correct Option: B
Explanation:
A child will inherit Y chromosome from father to become a boy and X chromosome to become a girl. In human being, Y is the factor of maleness.
Male parent:  XY     x     Female parent: XX
Gametes:      X, Y           X
Offspring:     XX (Female child) , XY  (Male child)

Mother is responsible for the sex of a baby.

biology mendel's law of inheritance determination of sex sex determination sex determination in humans

  1. True

  2. False

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Correct Option: B
Explanation:

The sex of the child is completely dependent on the father and not mother. This is because men are XY and women are XX. This means that the woman can only donate one X chromosome to her child, while the father can either donate an X or a Y. If the father donates the X to the child, it will be XX and become a female, if the father donates a Y to the child, it will be XY and will become a male.