std v sc plant question answer.

PLANT

D1.The  pigment present in green leaves of a plant is chlorophyll.

D2.Some plant feed on insects because, they grow in such a soil which lack nitrogen .To fulfill nitrogen requirement they kill insects and feed on them.

D3.The  two methods of reproduction  in plants are-

i)Reproduction through seeds (sexual reproduction)

ii)Reproduction through vegetative part(asexual reproduction)

D4.The conditions required for the proper germination of seeds are

i)                    proper amount of water

   ii)     Sufficient air

iii) Favorable temperature

      D5.Two plants that reproduces through stem cutting are –i) rose  ii)china Rose

E1.All seeds do not germinate to form new plant because germination of seed is a very complex process .It needs proper amount of water, air & favorable temperature. The seed which get the above mentioned condition germinate into a plant and those who do not get they    don’t germinate

E2.The seed normally germinate within a temperature range of 5⁰ to 45⁰  Celsius. But  the temperature in an ice box or refrigerator   is below 5 ⁰ Celsius which don’t support  germination. So seeds do not germinate when they are kept in an ice box or refrigerator.

E3.The importance of vegetative reproduction in plants are

1)It is an easier and faster  method of reproduction

2) The only method of reproduction in seed less plant is vegetative reproduction

3) Reproduction through vegetative parts needs less care &attention.

E4.Three natural ways of seed dispersal are-

1) Dispersal through water: coconut, sea bean, lotus & lily.

2) Dispersal through air: dandelion, cotton, maple & milk weed

3) Dispersal through  bursting or cracking: Pea, beans, ladyfinger                             

E5.One can grow a rose plant without seeds by stem cutting method.

6.(a)seed coat-It protects the embryo from unfavorable conditions like excess water, heat & freezing temperature.

b) cotyledons: It provides food to baby plants.

c) micropyle: It allows water and air to enter inside for germination

EXTRA QUESTION ANSWER

Q1.Name the tiny pores present on the leaf surface  for exchange of gases.

Ans: stomata

Q2.What is the largest seed producing fruit?

Ans:double coconut

Q3.List examples of three monocotyledons plant.

Ans:rice,wheat,maize,bamboo,grass.

Q4.What  is seed dispersal?

Ans:The process of transfer of seeds  to different places through different agent is called  seed dispersal.

Q5.Write agent of seed dispersal of the following  seeds.

i)xanthium

ii)cotton seed

iii)sea bean

iv)milk weed

v) hydrilla

vi)maple

vii)gulmohar(krushnachuda)

viii) cocklebur

ix)jackfruit

x)banyan