CBSE Solutions for Class 10 Biology

Select CBSE Solutions for class 10 Subject & Chapters Wise :

The number of paift(s) of sex chromosomes in the zygote of humans is ____________ .

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one

The theory of evolution of species by natural selection was given by ____________ .

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Darwin

Chromosomes are thread like structures in the nucleus of a cell formed of DNA which carriers the ____________ .

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genes

____________ genes are those which decide the appearance of an organism only in the presence of another identical gene.

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Recessive

____________ is the description of genes present in an organism.

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Genotype

Genes always work in ____________ .

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pair

The cut tail of an mice is an ____________ trait.

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acquired

____________ was the British scientist who proposed that life must have developed

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J.B.S Haldane

Acquired variations in somatic traits are not passed from generation to generation. [True/False]

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True

Human height is a trait which shows variations. [True/False]

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True

The formation of new species is called …………..

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Speciation

The earliest members of human species, Homo sapiens can be traced from …………..

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Africa

Human beings and chimpanzees had a ………….. ancestor a long time ago.

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common

Artificial selection of wild cabbage for arrested flower development and for sterile flowers has generated ………….. and ………….. respectively.

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Broccoli, cauliflower

Different structure but same function is a characteristic of ………….. organs.

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analogies

The more characteristics two species will have in common, the more ………….. they are related.

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closely

The notion of ………….. provides diversity without any adaptations.

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genetic drift

Sex of the child is largely ………….. determined in the human beings.

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genetically

The germ cells combine to restore the normal number of ………….. in the progeny.

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chromosomes

Explain the terms analogous and homologous organs with examples.

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Homologous organs are those organs that have the identical basic structural style and origin, however have completely different functions. For example: The forelimbs of humans and also the wings of birds look completely different outwardly however their complex body part is comparable.

Analogous organs are those organs that have the various basic structural style and origin however have similar functions. For example: The wings of birds and insects.

In evolutionary terms, we have more in common with

(a) A Chinese school-boy.

(b) A chimpanzee.

(c) A spider.

(d) A bacterium.

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Answer :

Correct answer – (b)

Humans and chimpanzees are connected since they belong to the identical order, Primates and same family, Homicide. However, a school going boy is he a person that belongs to homo. This suggests that the characteristics of a college are specifically a dead ringer for people at large.

Hence, in organic process terms, we have a tendency to be specifically almost like a college boy than to Pan Troglodytes.

What are fossils? What do they tell us about the process of evolution?

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Fossils are called the preserved remains of animals or plants or other organisms from the distant past. These fossils tell us about a lot of extinct animals and also give insights into how evolution might have occurred. Fossils can be used to build an organism’s evolutionary history. The pattern of fossil distribution gives us an idea of the time in history when various species were formed or become extinct. Fossil also helps trace some animal’s evolutionary history.

Give an example of characteristics being used to determine how close two species are in evolutionary terms.

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Answer :

Let us take the instance of humans and apes. Each of them has similar body style. Hair and exocrine gland glands are gifting in each the animals. Hence, these 2 animals are closely connected in organic process term. Currently take some common characters between a fish and a person. Rachis, brain box and jaws are gift in each of them. However fish and man look entirely different from one another. Hence, they’re not closely connected in organic process term; rather are like distant relatives.

What factors could lead to the rise of a new species?

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Factors that would cause the increase of a brand new species are as follows:

(a) Natural activity.

(b) Method of genetic drift.

(c) Mutation.

(d) Geographical isolation.

(e) Environmental factors on the isolated populations.

(f) Generative isolation for a protracted time.

(g) Quantum of genetic variant transmissible from one generation to the following generation.

Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?

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Answer :

As the tiger population is decreasing sharply, the genetic pool of the tigers is additionally decreasing. This results in a limitation on the variations which will be introduced within the genetic makeup of the tigers. This might need serious implications. For example, if a un-wellness spreads within the tiger population, it would swipe the whole population while not going any survivors. This might even cause their extinction.

What are the different ways in which individuals with a particular trait may increase in a population?

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Answer :

An individual attribute could increase in a population within the following 2 ways:-

(a) Natural selection: if an attribute is useful to a population, it’ll increase naturally.

As an example – inexperienced colorize beetles is favorable because it helps them in camouflage against the predators.

(b) Genetic drift: if a population faces AN accident such majority of its members get killed, the remaining members can pass away their traits to the following generations. This may result in a rise of the attribute within the population.

How is the sex of the child determined in human beings?

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Sex of child in humans is set by the sort of male haploid sex cell that fuses with the feminine egg. Throughout meiosis, all the gametes created by females contain solely the X chromosome (A + X), whereas males manufacture 2 varieties of gametes, 1/2 gametes with X- and 1/2 with Y-chromosome (A + X and A + Y). Fertilization of egg (A + X) with sperm cell carrying A+X chromosomes ends up in female descendant (AA + XX). Fertilization of egg (A+ X) with sperm cell carrying A+ Y chromosomes ends up in teenager (AA + XY).

How do Mendel’s experiments show that traits are inherited independently?

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Answer :

Law of independent assortment tells regarding segregation and distribution of things governing 2 totally different traits. Consequently, genes for the 2 traits gift on separate chromosomes are inheritable severally of every alternative. Throughout hybridization by plant scientist, it had been determined that once 2 pairs of attributes were considered; every trait expressed freelance of the opposite. For example Cross between a plant manufacturing spherical and yellow seeds (RR and YY) crossing with a plant producing wrinkled inexperienced seeds (err and by).

F1 offspring produces spherical and yellow seeds (R and R, and Y and y) during which spherical and yellow are dominant traits. F2 offspring were just like their folks and made spherical yellow seeds, whereas a number of them made wrinkled inexperienced seeds. However, some plants of the F2 offspring even showed new mixtures, like round-green seeds and wrinkled- yellow seeds. The cross quantitative relation of 9:3:3:1led to the Law of freelance Assortment that says regarding independent inheritance of traits.

How do Mendel’s experiments show that traits may be dominant or recessive?

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Answer :

According to law of dominance, an attribute is painted by 2 contrastive factors of a factor during a heterozygous individual; the allele/factor that may specific itself in heterozygous individual is named as dominant trait. The opposite issue, whose impact is cloaked by presence of dominant factor, is named recessive issue. Once Johann Mendel crossed one tall and one short leguminous plant, all the off springs (F1 generation) were tall. Once he self-crossed the F1 generation, among them 3/4th of the progenies were tall whereas 1/4th were short. So he ended that though the F1 relation had each tall and short traits, solely tall plants were discovered within the F1 generation, this implies that tallness may be a dominant attribute.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant ? Why or why not?
 

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This information is not enough. This is because each individual is carrying two alleles. The recessive trait can occur only when who alleles are similar. It blood group A is dominant and O is recessive, then daughter can have blood group O only when both recessive alleles occur together in mother, and father has one allele of O and other of A.

a. Transmission of characters from parents to offspring

Traits

b. It is a nucleic acid

Progeny

c. Alternative forms of the same character

Acquired

d. Term used for the offspring of two plants or animals of different species

DNA

 

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Answer :

a. Acquired
b. Traits
c. DNA
d. Progeny

  1. They are one of the evidence of evolution

Reproduce

  1.  A term for group of interbreeding organisms

Gene

  1. Segment of DNA which has information for a character

Gene

  1. Traits gained during lifetime

Species

  1. Organisms do this to perpetuate their own kind

Fossil

  1. Traits like earlobe are its example

Inherited

 

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Answer :

a. Fossil
b. Species
c. Gene
d. Inherited
e. Reproduce
f. Gene

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Browse & Download CBSE Books For Class 10 - All Subjects

The GSEB Books for class 10 are designed as per the syllabus followed Gujarat Secondary and Higher Secondary Education Board provides key detailed, and a through solutions to all the questions relating to the GSEB textbooks.

The purpose is to provide help to the students with their homework, preparing for the examinations and personal learning. These books are very helpful for the preparation of examination.

For more details about the GSEB books for Class 10, you can access the PDF which is as in the above given links for the same.

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