How do Organisms Reproduce?: Class 10 Science Q&A · Page 3

112 free answers on How do Organisms Reproduce? (Science) for Class 10 students, across CBSE, ICSE and State boards.

Question & Answer

Questions

112 TOTAL

ScienceClass 10CBSE
1. The number of chromosomes in parents and offsprings of a particular species remains constant due to (a) doubling of chromosomes after zygote formation (b) halving of chromosomes during gamete formation (c) doubling of chromosomes after gamete formation halving of chromosomes after gamete formation
Soln: Answer is (b) halving of chromosomes during gamete formation Explanation: Because of halving of chromosome during gamete formation number of chromosome remain same as somatic cell of an organism. Halving of gametes in a chromosomes is called diploid number of chromosomes.
ScienceClass 10CBSE
1. The correct sequence of reproductive stages seen in flowering plants is (a) gametes, zygote, embryo, seedling (b) zygote, gametes, embryo, seedling (c) seedling, embryo, zygote, gametes gametes, embryo, zygote, seedling
Answer is (a) gametes, zygote, embryo, seedling Explanation: Gametes fuse to form a zygote during fertilization. After fertilization embryo will be formed which will lead to seedling in plants.
ScienceClass 10CBSE
1. The ability of a cell to divide into several cells during reproduction in Plasmodium is called (a) budding (b) reduction division (c) binary fission multiple fission
Answer is (d) multiple fission Explanation: Plasmodium divide into many daughter cell by binary multiple fission. In Multiple fission nucleus of the cell divides multiple times by mitosis then separates to create multiple daughter cells.
ScienceClass 10CBSE
1. In Spirogyra, asexual reproduction takes place by (a) breaking up of filaments into smaller bits (b) division of a cell into two cells (c) division of a cell into many cells (d) formation of young cells from older cells.
Answer is (a) breaking up of filaments into smaller bits Explanation: Spirogyra reproduce by fragmentation. Spirogyra simply breaks up into smaller pieces upon maturation. These pieces or fragments grow into new individuals
ScienceClass 10CBSE
1. A feature of reproduction that is common to Amoeba, Spirogyra and Yeast is that (a) they reproduce asexually (b) they are all unicellular (c) they reproduce only sexually (d) they are all multicellular
Answer is (a) they reproduce asexually Explanation: Amoeba reproduce by binary fission, Spirogyra reproduce by fragmentation, yeast reproduce by budding.
ScienceClass 10CBSE
1. Characters that are transmitted from parents to offspring during reproduction show (a) only similarities with parents (b) only variations with parents (c) both similarities and variations with parents neither similarities nor variations
Soln: Answer is (c) both similarities and variations with parents
ScienceClass 10CBSE
1. Characters transmitted from parents to offspring are present in (a) cytoplasm (b) ribosome (c) golgi bodies genes
Soln: Answer is (d) genes
ScienceClass 10CBSE
1. Offspring formed by asexual method of reproduction have greater similarity among themselves because (i) asexual reproduction involves only one parent (ii) asexual reproduction does not involve gametes (iii) asexual reproduction occurs before sexual reproduction (iv) asexual reproduction occurs after sexual reproduction (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iv) (iii) and (iv)
Soln: Answer is (a) (i) and (ii) Explanation: Asexual reproduction involve single parent and there will be no exchange of gametes hence offspring looks similar to their parent
ScienceClass 10CBSE
1. Which of the following is the correct sequence of events of sexual reproduction in a flower? (a) pollination, fertilisation, seedling, embryo (b) seedling, embryo, fertilisation, pollination (c) pollination, fertilisation, embryo, seedling embryo, seedling, pollination, fertilization
Answer is (c) pollination, fertilisation, embryo, seedling Explanation: Pollination leads to fertilization after which embryo is formed. Seedling comes out from embryo.
ScienceClass 10CBSE
1. In a flower, the parts that produce male and female gametes (germ cells) are (a) stamen and anther (b) filament and stigma (c) anther and ovary stamen and style
Soln: Answer is (c) anther and ovary
ScienceClass 10CBSE
1. In the list of organisms given below, those that reproduce by the asexual method are (i) banana (ii) dog (iii) yeast (iv) Amoeba (a) (ii) and (iv) (b) (i), (iii) and (iv) (c) (i) and (iv) (ii), (iii) and (iv)
Answer is (b) (i), (iii) and (iv) Explanation: Dog reproduce sexually, yeast reproduce by budding, Amoeba reproduce sexually and cultivated banana also reproduce asexually.
ScienceClass 10CBSE
Give reasons for the appearance of new combinations of characters in the F2 progeny.
Soln: The appearance of new combinations in the F2 generation can be explained through the law of independent assortment, according to which when two traits are combined in a hybrid, one pair of character segregates independent of the other pair of characters. The two genes segregate independently at the time of gamete formation and recombine at the time of fertilisation to produce zygote with combinations different from parents as well. E.g. wh
ScienceClass 10CBSE
Give the basic features of the mechanism of inheritance.
Soln: The basic features of the mechanism of inheritance are as follows: Genes control the characters Genes are present in two or more forms One form of a gene may be dominant over another Genes are present in chromosomes Individual genes exist in two forms that may be similar or dissimilar Two forms of the gene separate at the time of gamete formation Two forms of g
ScienceClass 10CBSE
Study the following cross and show self-pollination in F1, fill in the blank and answer the question that follows. Parents RRYY Round, yellow x rryy wrinkled, green F1 — Rr Yy Round, yellow x ?
Soln: Parents RRYY x rryy Round, yellow wrinkled, green F1 — Rr Yy x RrYy Round, yell
ScienceClass 10CBSE
1. In the following crosses, write the characteristics of the progeny. Cross Progeny 1. RR YY x RR YY Round, yellow Round, yellow 2. 1. Rr Yy x Rr Yy Round, yellow Round, yellow 2. 1. rr yy x rr yy Wrinkled, green wrinkled, green 2. 1. RR YY x rr yy Round, yellow wrinkled green 2.
oln: Cross 1. RR YY x RR YY.................................... Round, yellow Round, yellow Progeny Round, yellow 1. Rr Yy x Rr Yy.................................... Round, yellow Round, yellow Round, yellow Round, green Wrinkled, yellow Wrinkled, green
ScienceClass 10CBSE
1. Evolution has exhibited greater stability of the molecular structure when compared with morphological structures. Comment on the statement and justify your opinion.
Soln: Structures which are apparent to our eyes are called morphological structures. Molecular structures are those biomolecules which are the integral components of organisms. We see a lot of diversity all around us. This diversity is possible because of diversity in morphological structures. This shows that morphological structures are the least stable. Life, which began as simple forms on the earth, is now composed of many complex forms. Life has evolved fo
ScienceClass 10CBSE
Give reasons why acquired characters are not inherited.
Acquired characters are the results of ou
ScienceClass 10CBSE
Differentiate between inherited and acquired characters. Give one example for each type.
Soln: Inherited Characters Acquired Characters Characters that are passed on from parents to offspring Alters genotype and phenotype Transmitted to future generation Characters appear in an individual’s lifetime but cannot be transmitted to the next gener
ScienceClass 10CBSE
All the human races, like Africans, Asians, Europeans, Americans and others, might have evolved from a common ancestor. Provide a few pieces of evidence in support of this view
Soln: All human races appear to be different, but they have evolved from common ancestry. The following is the evidence to support this view: Common body Same physiological and metabolic Fixed number of Freely Common genetic blueprint
ScienceClass 10CBSE
1. Bacteria have a simpler body plan when compared with human beings. Does it mean that human beings are more evolved than bacteria? Provide a suitable explanation.
Soln: This is an issue of debate. It depends on the way we evaluate evolution. If the complexity of the body is a parameter, then humans are far superior to bacteria. Bacteria have a cellular level of organisation, and humans have an organ-system level organisation. On the other hand, if we consider the ability to survive, bacteria have evolved more than human beings. Humans can live in any environment but with artificial protection. Humans cannot live in a ha

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How do Organisms Reproduce?: Class 10 Science Q&A · Page 3

Questions

1. The correct sequence of reproductive stages seen in flowering plants is (a) gametes, zygote, embryo, seedling (b) zygote, gametes, embryo, seedling (c) seedling, embryo, zygote, gametes gametes, embryo, zygote, seedling

1. The ability of a cell to divide into several cells during reproduction in Plasmodium is called (a) budding (b) reduction division (c) binary fission multiple fission

1. In Spirogyra, asexual reproduction takes place by (a) breaking up of filaments into smaller bits (b) division of a cell into two cells (c) division of a cell into many cells (d) formation of young cells from older cells.

1. A feature of reproduction that is common to Amoeba, Spirogyra and Yeast is that (a) they reproduce asexually (b) they are all unicellular (c) they reproduce only sexually (d) they are all multicellular

1. Characters that are transmitted from parents to offspring during reproduction show (a) only similarities with parents (b) only variations with parents (c) both similarities and variations with parents neither similarities nor variations

1. Characters transmitted from parents to offspring are present in (a) cytoplasm (b) ribosome (c) golgi bodies genes

1. Which of the following is the correct sequence of events of sexual reproduction in a flower? (a) pollination, fertilisation, seedling, embryo (b) seedling, embryo, fertilisation, pollination (c) pollination, fertilisation, embryo, seedling embryo, seedling, pollination, fertilization

1. In a flower, the parts that produce male and female gametes (germ cells) are (a) stamen and anther (b) filament and stigma (c) anther and ovary stamen and style

1. In the list of organisms given below, those that reproduce by the asexual method are (i) banana (ii) dog (iii) yeast (iv) Amoeba (a) (ii) and (iv) (b) (i), (iii) and (iv) (c) (i) and (iv) (ii), (iii) and (iv)

Give reasons for the appearance of new combinations of characters in the F2 progeny.

Give the basic features of the mechanism of inheritance.

Study the following cross and show self-pollination in F1, fill in the blank and answer the question that follows. Parents RRYY Round, yellow x rryy wrinkled, green F1 — Rr Yy Round, yellow x ?

1. In the following crosses, write the characteristics of the progeny. Cross Progeny 1. RR YY x RR YY Round, yellow Round, yellow 2. 1. Rr Yy x Rr Yy Round, yellow Round, yellow 2. 1. rr yy x rr yy Wrinkled, green wrinkled, green 2. 1. RR YY x rr yy Round, yellow wrinkled green 2.

1. Evolution has exhibited greater stability of the molecular structure when compared with morphological structures. Comment on the statement and justify your opinion.

Give reasons why acquired characters are not inherited.

Differentiate between inherited and acquired characters. Give one example for each type.

All the human races, like Africans, Asians, Europeans, Americans and others, might have evolved from a common ancestor. Provide a few pieces of evidence in support of this view

1. Bacteria have a simpler body plan when compared with human beings. Does it mean that human beings are more evolved than bacteria? Provide a suitable explanation.