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State the number of sets of chromosomes present in a zygote.
Concept: Sexual Reproduction in Plants
Sexual maturation of reproductive tissues and organs are necessary link for reproduction. Elucidate.
Concept: Sexual Reproduction in Plants
Explain the post fertilization changes that occur in the ovary of a flower.
Concept: Sexual Reproduction in Plants
Given below is a diagram of a germinating seed. Label the parts that:
- gives rise to future shoot.
- gives rise to future root system.
- stores food.
Concept: Sexual Reproduction in Plants
State the post-fertilisation changes that lead to fruit formation in plants.
Concept: Sexual Reproduction in Plants
Two pea plants - one with round yellow seeds (RRYY) and another with wrinkled green (rryy) seeds produce F1 progeny that have round, yellow (RrYy) seeds.
When F1 plants are self-pollinated, which new combination of characters is expected in F2 progeny? How many seeds with these new combinations of characters will be produced when a total 160 seeds are produced in F2 generation? Explain with reason.
Concept: Gregor Johann Mendel – Father of Genetics
Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.
What will be set of genes present in the F1 generation?
Concept: Gregor Johann Mendel – Father of Genetics
Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.
Give a reason why only tall plants are observed in F1 progeny.
Concept: Gregor Johann Mendel – Father of Genetics
Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.
When F1 plants were self-pollinated, a total of 800 plants were produced. How many of these would be tall, medium height or short plants? Give the genotype of F2 generation.
Concept: Gregor Johann Mendel – Father of Genetics
Sahil performed an experiment to study the inheritance pattern of genes. He crossed tall pea plants (TT) with short pea plants (tt) and obtained all tall plants in F1 generation.
When F1 plants were cross-pollinated with plants having tt genes, a total of 800 plants were produced. How many of these would be tall, medium height or short plants? Give the genotype of F2 generation.
Concept: Gregor Johann Mendel – Father of Genetics
What does sign of power (+ve or –ve) indicate?
Concept: Power of a Lens
How unit of power related to focal length of a lens?
Concept: Power of a Lens
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
What will be the focal length of this mirror?
Concept: Spherical Mirrors
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
Which type of spherical mirror will it provide?
Concept: Spherical Mirrors
Define the following terms in the context of spherical mirrors :
(i) Pole
(ii) Centre of curvature
(iii) Radius of curvature
(iv) Principal axis
Concept: Spherical Mirrors
An optical device has been given to a student and he determines its focal length by focusing the image of the sun on a screen placed 24 cm from the device on the same side as the sun. Select the correct statement about the device.
(A) Convex mirror of focal length 12 cm
(B) Convex lens of focal length 24 cm
(C) Concave mirror of focal length 24 cm
(D) Convex lens of focal length 12 cm
Concept: Spherical Mirrors
AB and CD, two spherical mirrors, from parts of a hollow spherical ball with its centre at O as shown in the diagram. If arc AB = `1/2` arc CD, what is the ratio of their focal lengths? State which of the two mirrors will always form virtual image of an object placed in front of it and why.
Concept: Spherical Mirrors
Name the type of lens whose power is positive.
The image of an object formed by a lens is real, inverted and of the same size as the object. If the image is at a distance of 40 cm from the lens, what is the nature and power of the lens ? Draw ray diagram to justify your answer.
Concept: Power of a Lens
A student obtained on a screen the sharp image of a candle flame placed at the farther end of laboratory table using a concave mirror. For getting better value of focal length of the mirror, the teacher suggested to him to focus the sun. What should the student do?
(A) Should move the mirror away from the screen.
(B) Should move the mirror towards the screen.
(C) Should move the mirror and screen both towards the sun.
(D) Should move only the screen towards the sun.
Concept: Spherical Mirrors
State the types of mirrors used for (i) headlights and (ii) rear view mirror, in cars and motorcycles. Give to justify your answer in each case.
Concept: Spherical Mirrors
