Important questions in biology for class 12th

Important questions in biology for class 12th

◆Introduction:– hi guys in this article we know about important questions in biology for class 12th with answer for JAC from Biology lesson- 1 reproduction in organisms. In this topic we include very short answer type questions short answer type questions in simple language which may be asked in your coming Jharkhand academic Council Ranchi board examination from 12th biology. We know that board examination of 12th Biology containing multiple choice questions, fill in the blanks ,matching type questions ,very short answer type questions ,short answer type questions .In lesson 1 reproduction in organism biologysir.com try to explain each subtopics of this chapter like life span of organism asexual reproduction sexual reproduction parthenogenesis external fertilization and internal fertilization .biology sir.com provide you important questions with answer in simple language.Important questions in biology for class 12th which will be ask in  several state board examination.

Important short type questions in biology class 12th

Q1) what is life span ?

Ans. The period from birth to the natural death of an organism is known as life span .every organism have a specific and different life span. For example life span of elephant is 70 to 90 years and life span of man is 60 to 80 years.

Q2) what is reproduction?

Ans. Reproduction is biological process in which an organism give rise to birth of their child or young ones (offsprings).

Q3) what is two types of reproduction?

Ans. There is two types of reproduction
A) Asexual reproduction
B) Sexual reproduction

Q4) what is asexual reproduction ?

Ans. That type of reproduction in which there is no formation of gametes and fusion of gametes and offspring which are produce is is identical and represent the exact copy of their parents is called as asexual reproduction

Q5) what do you mean by clone ?

Ans. Clones are young ones which are developed from asexual reproduction and that is morphologically and genetically similar individuals to their parents.

Q5) what is difference between binary fission and Multiple Fission

Ans. A) in binary fission parents body divide in two daughter cells and in Multiple Fission parents body divides in many daughter cells.

B) binary fission take place during favourable condition and Multiple Fission takes place during unfavourable conditions.

C) in binary fission nothing is left with parents but in in Multiple Fission residual cytoplasm is left

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Q6) what do you mean by vegetative propagation ?

Ans. Process of multiplication in which one part of of plant like stem roots and leaves germinate and develop into new plants.like that A) roots – shisham, guava Dahlia sweet potato and etc
B)from stem – banana, Ginger ,turmeric etc.

Q7) what are the different process of vegetative propagation.
Ans.1) natural methods:-
A) Roots – sheesham plant guava plant Dahlia sweet potato
B) stem tuber-poato
C) bulbs – onion garlic
D)runner -Doob grass
E)leaf – bryophyllum
2) artificial methods :-
A) cutting – sugarcane
B) grafting- mango
C) budding – rose
D) Layering – Jasmine
E) bulbil -Agave

Q8) why water hyacinth is known as terror of Bengal ?

Ans. Water hyacinth is aquatic herbs and one of the most fast growing weeds found in standing water of Ponds and lake. it’s make water efficient that leads to death of fishes and other aquatic organisms .that’s why it is called as terror of Bengal.

what do you mean by offspring?

Ans. New born child or young ones develop from sexual reproduction is known as off spring (new ones)

different between clones and off spring

Ans. clones are developed from asexual reproduction and offspring are developed from sexual reproduction
B) clones are genetically and morphologically identical to their parents but offspring are quite different from their parents.

 what is sexual reproduction

Ans. It is that type of reproduction in which there is a formation of male and female gametes, fusion of gametes to form zygote and development of new child from zygote by the process of embryogenesis is known as sexual reproduction.

■Important questions answer for JAC class 12th Biology lesson- 1 reproduction in organisms

main steps in sexual reproduction

There are four main step in sexual reproduction :-

1) before fertilization:-
a) formation of male and female gametes
b) transfer of gametes

2) after fertilization:-
c) zygote formation
d) embryogenesis

 hermaphrodite definition

Ans. Some animals like earthworm sponge tapeworm and leech have both male and female reproductive organs so they are called as hermaphrodite.

definition of monoecious and dioecius

Ans. The plant which have both male and female flowers are termed as monoecious
Ex . Maize ,castor

When male and female flower are present on different plants are called as dioecious .ex- papaya, Mulberry

 what is fertilization

Ans. It is biological process in which there is a complete and permanent fusion of two haploid gametes to form diploid zygote.

main two types of fertilization

There are two types of fertilization external fertilization and internal fertilization

Ans. 1) external fertilization
2)internal fertilization

Q17) what do you mean by external fertilization

Ans. Type of fertilization in which formation of zygote take place from outside the female body in water. This type of fertilization is found in some fishes frogs and Cockroach. male and female frog release their sperm and eggs respectively in water from outside the body and by the chance fusion of gametes and fertilization takes place to form the zygote.

Q18) what do you mean by internal fertilization ?

Ans. Types of fertilization in which formation of zygote take place inside the female body. This types of fertilization found in reptiles birds and mammals.

what is false fruit

Ans. The types of fruits which are not develop from ovary but developed from other parts of tissue exterior to carpel. For example Apple is false fruit develop from thalamus.

what is true fruit?

Ans. The fruit which are developed from ovary known as true fruits. for example Mango

what is oestrous cycle ?

Ans. Oestrous cycle is a recurring of physiological change which are induce by reproductive hormone in mammalian non primate female. Oestrous phase is heat stage for breeding and anaestrus phase is cold stage for breeding.

■Important questions answer for JAC class 12th Biology lesson- 1 reproduction in organisms

 main difference between oestrous cycle and menstrual cycle

Ans. 1) oestrous cycle is found in non-primates mammalian female like Tiger cow lion etc. And menstrual cycle is found in primates mammalian female and like ape monkey man

2) oestrous cycle is seasonal breeder but menstrual cycle is breed throughout the year.

3) oestrous cycle have two stage it is stage and cold stage but in menstrual cycle there is physiological change in ovary induced by hormones.

what do you mean by monocarpic plant

Ans. The plant which produce flower once in their lifetime is known as monocarpic plant for ex- bamboo tree

Q24) what do you mean by polycarpic plant

Ans. The plant which produce flower several times in their lifetime is known as polycarpic plant for example Mango tree.

 difference between isogamy and anisogamy

Ans.1) In isogamy two fusing gametes are similar shape and size but in anisogamy two fusing gametes are different shape

2) isogamy found in Algae but anisogamy found in human beings and fungi

parthenogenesis definition

Ans. The process in which unfertilized ovum directly develop into fully formed haploid organism is known as parthenogenesis. For example Honey Bee

Q27) what are parthenocarpic fruit

Ans. The fruit which are developed without fertilization is known as parthenocarpic fruit for example banana

Q28) identify each part and write whether it is haploid or diploid:-

Ans. 1)ovary-diploid
2) anther- diploid
3) Eggs – haploid
4) pollen- haploid
5) male gametes-haploid
6) zygote – diploid

Q29) why is reproduction essential for organisms?

Ans. Reproduction is required for extension of life of species and maintain continuity of thread of life and it’s enable the spacies to live generation after generation that’s why reproduction is essential for any organism

Q30) which is the better mode of reproduction sexual or Asexual .why? Or offspring formed due to sexual reproduction have better chance of survival why?

Ans. Sexual reproduction is the better mode of reproduction due to following:-
a) sexual reproduction introduce variation in offspring that is necessary for evolution
b) it helps the offspring to adjust their body according to change in environment
c) due to new character combination better offspring are produce.

Q31) what is meant difference between zoospore and zygote

Ans. a) zoospore are formed during asexual reproduction in lower plants like algae and fungi but zygote are formed due to fusion of male and female gametes in sexual reproduction

b) zoospore are haploid but zygote is diploid

c) zoospore are motile due to presence of flagella but zygote are non- motile.

Q32) why offspring of oviparous animals are at greater risk?

Ans. In oviparous animals like birds and reptiles eggs are laid outside the body and all of their embryonic development is exposed to harmful environmental and biological factors like Predator so chance of death are high in such cases.

 

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■Important questions answer for JAC class 12th Biology lesson- 1 reproduction in organisms