Biology
Answer Key ( Class- 9th)
Q-1
Mention two food requirements of milch animals.
Ans-1 Roughage and
Concentrate
Q- 4
Which organelle is involved in formation of lysosomes ?
Ans-4 Golgi apparatus
Q-11 Write symptoms when following organs are
targeted by microbes ?
OR
1. Give
two examples of air borne diseases
2. Why
does a person suffering from aids dies even due to small infection ?
3. In many species of mosquitoes, the males
do not prefer human blood but females do. State Why?
Ans-11 (a) Lungs - Cough and
breathlessness
(b) Liver - Jaundice and our body will become pale
(c) Brain - Headaches, vomiting ,
fits or uncousciousness
OR
1.
Influenza and tuberculosis
2.
Aids is a complex of diseases. Its pathogen HIV virus weakens our immune system
and damages its function. That’s why every small cold can become pneumonia and a minor gut like infection can produce
diarrhea . Ultimately, these infections kill the people.
3.
Female mosquitoes prefer human blood because they need human warm blood for
nourishment of themselves and to lay eggs while males do not have such
requirement.
Q-12 What are the consequences of following
conditions ?
Ans-11
(a) When a cell contains higher water concentration than its external
surroundings, it will loose water to its external surroundings due to osmosis
and will become shrink
(b) When a cell contains lower water
concentration than its external surroundings, it will gain water from its
external surroundings due to osmosis and will swell up
(c) When a cell has equal water concentration
than its external surroundings, then there is no net movement of water and a
cell remains unaffected.
Q-18 A student visited a fish farm where he
found catla, rohu, mrigals, common carps and grass carps cultured in same pond
(a) Name
the type of fish farming observed by student
(b) What
is the main problem in such farming ?
(c) How
do farmers overcome such problems ?
Ans-18
(a) Composite fish culture
(b)
One problem with this type of fish culture is that these fishes breed only in
monsoon season. So a major problem is lack of availability of good quality
seed.
(c) Farmers overcome such problems by
introducing hormonal stimulations on fishes
Q-19 What precautions can you take in your
school to reduce the incidence of infectious diseases?
Ans - I will spread awareness about the consequences of
infectious diseases. I will ensure that every child washes his hand before
eating and after eating his/her food. I will advice our canteen manager to not
to sell stagnant food and I will also
advice an affected child to take leave from school so the disease wont’t
spread.
Q-23 (a) In the table given below are the names
of some plants. Write their division and also identify the odd plant of the
group
PLANTS
|
DIVISION
|
ODD MEMBER
|
(1) bacteria, yeast, paramecium,
euglena
(2) Spirogyra, chara, ulva,
mushroom, laminoria
(3) zarnia, pinus, equistem,
cycas
|
(b) Who
introduced the system of nomenclature ?
(c) Rana
tigrina is the scientific name of frog, what do these two terms imply
OR
Identify
the phylum of kingdom animalia in which animal has
(a) a pseudocoelom
(b) a
water driven tube system
(c)
jointed legs
(d)
pores in the body leading to canal system
(e)
notochord at some stages of their life
Ans-23
(a)
PLANTS
|
DIVISION
|
ODD MEMBER
|
(1) bacteria, yeast,
paramecium, euglena
(2) spirogyra, chara,
ulva, mushroom, laminoria
(3) zarnia, pinus,
equistem, cycas
|
unicellular
Algae
Gymnosperms
|
Bacteria
Mushroom
Equistem
|
(b)
Carolus Linnaeus
(c)
Rana is the genetic name of the common frog and tigrina is the specific name of
the common frog
OR
(a)
Nematoda
(b)
Echinodermata
(c)
Arthropoda
(d)
Porifera
(e)
Protochordata
Q-25 (a) Draw a diagram of cardiac muscle and
label any two parts.
(b) Name
the following
1.
Living tissue that provides mechanical support to plants
2. Animal tissue with elongated
cells and contractile proteins responsible
for movement
3. Highly specialized cells for
being stimulated and then transmitting the stimulus very rapidly
Ans-25
(a)
(b) 1. Collenchyma
2. Muscle tissue
3. Neuron
Q-26 What is used while preparing a temporary
mount of human cheek cells and why ?
Ans-26
Glycerine, cover slip and methylene blue are used in preparing a temporary
mount of human cheek cells. Glycerine protects that cheek cell from being
dehydrated and keeps them wet. Methylene blue is used for staining. Nucleus and cytoplasm take the stain and are
visible under microscope. Cover slip is used protect cell from getting direct contact with microscope and prevents
fungal infection on cell.
Q-27 You have been given two slides of
collenchyma and sclerenchyma. How will you identify them on basis of cell wall
and nucleus ?
Ans
-27 Cell wall of collenchyma is made up of cellulose and is thickened at
corners whereas cell wall of sclerenchyma are thick but are lignified.
Collenchyma nucleus is prominent at the periphery with cytoplasm but the centre
of the cell consists of vacuole and sclerenchyma lack as these cell are dead or
sometimes have very undeveloped nucleus.
Q-28 Coakroach belongs to which phylum ? Write
any two identifying features of the phylum.
Ans-28
Coakroach belongs to phylum Arthropoda. Its features are
1.
It have joint appendages
2.
It's body has well developed head and distinct eyes
