Life Science Solution–2020

Group A

1. Multiple choice question.
1.1 Select the correct pair-
(a) Cerebrum- Maintenance of balance of the body
(b) Hypothalamus-Control of intelligence and emotion
(c) Cerebellum-Control of body temperature
(d) Medulla Oblongata-Control of heart beat and swallowing of food (Ans)

1.2 Identify which of the following statement is not true regarding Insulin-
(a) Helps in the absorption of glucose from the blood into most of the somatic cells
(b)Converts glucose into glycogen within liver and muscle cells
(c) Helps in the conversion of fat and protein into glucose (Ans)
(d)Inhibits the conversion of protein and fat into glucose

1.3 Match the following words of column-A with that of column-B and select which of the following option is correct-
Column-A      Column-B
A. Flexion     (i) Quadriceps
B. Extension  (ii) Piriformis
C. Rotation    (iii) Biceps
(a) A-(i) B-(ii) C-(iii)
(b) A-(ii) B-(iii) C-(i)
(c) A-(iii) B-(i) C-(ii) (Ans)
(d) A-(ii) B-(i) C-(iii)

1.4 Determine from the answers given below in which phases of karyokinesis during mitotic cell division following two incidents happen-
(A) Daughter chromosomes tend to move apart from each other towards their own poles
(B) Nuclear membrane and nucleolus disappear
(a) (A)Prophase (B) Anaphase
(b) (A)Anaphase (B) Prophase (Ans)
(c) (A) Telophase (B) Metaphase
(d) (A) Metaphase (B) Telophase

1.5 Which of the following is the feature of cross pollination-
(a) Occurs within the same flower of same plant
(b) Agents are not required
(c) Lesser chance of new characters being transmitted
(d) More wastage of pollen grains (Ans)

1.6 Determine the number of DNA molecules that get coiled to form each chromosome in a newly formed daughter cell produced by mitotic cell division in human body-
(a) 46 (b)1 (Ans) (c) 23 (d) Numerous

1.7 Identify the genotype of Guinea pig having black colour and rough hair –
(a) BbRr, BBRr (Ans) (b) BBrr, Bbrr
(c) bbRR, bbRr (d) bbrr, bbRr

1.8 Decide which of the following two were selected by Mendel as recessive traits –
(a) Colour of follower-purple, Position of flower-axial
(b)Length of stem-dwarf, Form of ripe seed-wrinkled (Ans)
(c) Form of ripe seed-round, Colour of seed yellow
(d) Position of flower-axial, length of stem-tall

1.9 Assess from the following, the probable genotype parents having haemophilic son and normal daughter-
(a) H||h, h|↑ (b) H||H, H|↑
(c)H||H, h|↑ (d) H||h, H|↑ (Ans)

1.10 Parthenium is an exotic species in our country. Other indigenous species cannot survive in such a place where it grows. This establishes one of the postulates of Darwin’s theory. Identify the postulate-
(a) Intraspecific struggle (b) Interspecific struggle (Ans)
(c) Struggle with environment (d) Origin of species

1.11 Miller and Urey, in their experiment, were able to synthesize some preliminary constituents necessary for the creation of life. Identify the ones which were amino acids among them-
(a) Lactic acid, Acetic acid (b) Urea, Adenine
(c) Glycine, Alanine (Ans) (d) Formic acid, Acetic acid

1.12 Decide for which of the following purposes bees demonstrate waggle dance-
(a) search for reproductive mates
(b) Inform other worker bees about the direction and distance of the source of food from the bee have (Ans)
(c) selecting places for the construction of the new bee have
(d) Avoid attack by probable enemy

1.13 Identify which of the following is the correct information related to biosphere reserve-
(a) Conservation is promoted to local people and other biotic communities along with conservation of ecosystem (Ans)
(b) National park and sanctuary are not included within the biosphere reserve
(c) The presence and participation of local people for the conservation of the ecosystem is not permissible
(d) Its size usually smaller than the Sanctuary

1.14 Decide which of the following pair is not correct-
(a) poaching-increase the endangeredness of gorilla
(b) Exotic Species-Lantana, Tilapia
(c) Determination of hotspot-Number of endemic species and endangered species
(d) Greenhouse gas-Eutrophication (Ans)

1.15 Decide which of the following Tiger Project is located within our state-
(a) Bandipore (b) Simlipal
(c) Sundarbans (Ans) (d) Kanha

Group B

2. Answer any 21 question out of 26 questions given below as instructed: –
Fill in the blanks with proper words in the following sentences (any five): –

2.1 Acharya Jagdish Chandra Bose proved the property of Senstivity by sending electrical impulse in Mimosa and Desmodium plant.

2.2 If gametes in human were produced by mitosis instead of meiosis then the number of autosomes in a somatic cell of an offspring would have been 88.

2.3 A disease in human population caused by recessive gene located in ‘X’ Chromosome is Haemophilia.

2.4 The hoof of modern horse is the transformation of the digital number third of ancestors.

2.5 At the neitrification phase of nitrogen cycle ammonia is converted into nitrite and nitrate by the action of some bacteria.

2.6 To produce the bottled cold drinks widely sold in the market, a lot of fresh water is wasted.

Decide whether the following statements are true or false (any five)

2.7 Tropic movement is the movement is the movement of growth in plants. True

2.8 Crossing over takes place during mitotic cell division.False

2.9 Mendel used the term gene while describing his experiment related to with heredity.False

2.10 The leaf of cactus is modified into spine for the reduction of the rate of transpiration.True

2.11 Rhododendron is an endangered plant species conserved in Eastern Himalaya hotspot.True

2.12 Choroid helps in the accommodation of eye by changing the curvature and shape of the lens.False

Match the right column with the left column: (Any five):

Answer in a single word or in a single sentence (any six) :

2.19 Chose the odd one and write it :
Cerebrum, Hypothalamus, Pons, Thalamus

2.20 Where the Schwann cells are located?
Ans: Schwann cells are located in axon.

2.21 A pair of related terms is given below. On the basis of the relationship in the first pair write the suitable word in the gap of second pair.
Mitosis: Radicle : Meiosis: Ovum

2.22 Which law Mendel concluded from his dihybrid cross experiment?
Answer:Law of independent Assortment was concluded from Mendel’s dihybrid cross experiment.

2.23 Give an example of a variation found among healthy persons which is transmitted through generations?
Ans: Eye colour is a variation found among healthy persons which is transmitted through generations.

2.24 How Chimpanzees break open the hard shell for eating the nuts?
Ans: Chimpanzees used Stone as a hammer to break open the hard shell for eating the nuts.

2.25 Among the following four terms one includes the other three, find out that term and write it:
SPM, Air Pollution, Greenhouse gas, Lung disease

2.26 Name the practice which jointly the local peoples and forest department maintain for reclamation of forest?
Ans: JFM (Joint Forest Management) is the name of thepractice which jointly the local peoples and forest department maintain for reclamation of forest.

Group C

3. Answer any 12 questions in 2-3 sentences out of 17 questions given below:

3.1 Distinguish between the functions of hormone and nervous system on the following parameters:
Nature of function
Place of function
Time span of function
fate

3.2 ‘A person can see distant objects distinctly but is unable to visualize near object in a perfect way’- Predict what would be the probable cause and suggest the corrective measure for such a problem
Ans: As the person unable to visualize the near object then he must be suffering from short sightedness or myopia. This defect may be corrected by concave lens spectacles of suitable power.

3.3 Analyse the role of synthetic plant hormone in increasing the production and solving the problem of weed in agriculture?
Ans:

3.4 ‘LH or ICSH control the secretion of hormones of reproductive glands of human body’ – judge the validity of the statement?
Ans: As the LH and ICSH stimulate the Leyding cells in male to secrete testosterone and in female the corpus luteum to secrete progesterone. This valid the statement.

3.5 How can you distinguish between mitosis of plant cells and that of animal cells on the basis of formation of spindle fibre and the process of cytokinesis?
Answer:

3.6 Establish the relationship between the formation of malignant tumour in the human body with the loss of control in the cell cycle?
Ans: A disregulation of the cell cycle components may lead to tumour formation. When some genes like the cell cycle inhibitors/ RB. P53 etc., mutate, they may cause the cell to multiply uncontrollably, forming a tumour. Although the duration of cell cycle in tumour cells is equal to or longer than normal cell cycle, the proportion of cells that are in active cell division in tumours is much higher than that in normal tissue.Thus, the number of cells increase and become malignant and may result in cancer.

3.7 ‘The adventitious leaf bud plays significant role in natural vegetative propagation of plant’ – Evaluate the validity of the statement with a proper example?
Ans: Natural vegetative propagation occurs when an axillary bud grows into a lateral shoot and develops its own roots (also known as adventitious roots).This valid the statement.

3.8 Show with the help of cross, who is more important among parents in determining the sex of their offspring?
Answer: From the cross, we can conclude that father is more important in determining the sex of the offspring because if the X chromosome fertilises the mother gametes then the offspring will be a girl and if Y chromosome fertilises the mother gametes then the offspring will be a boy.

3.9 ‘Different genotypes produce the same phenotype’ – Justify the statement in the form a table by taking an example from the result of dihybrid cross of pea plant?
Answer: In the table, we can see the genotype of YYRR,YYRr,YyRR,YyRr are different but their phenotype is same example–Yellow Round.

3.10 Give your opinion about probable suggestions which can be given to pair of contenders before marriage in order to prevent the spread of a genetic disease from the society already known to you?
Ans: In order to prevent the spread of a genetic disease, the pair of contenders must do genetic counselling so that the risk of a disorder may be prevented.

3.11 A good number of Tilapia fishes are released in a pond having only different indigenous fish species grown naturally. Think and write which types of struggle for existence Tilapia fishes have to face in order to survive?
Ans: There are two types of struggle of existence tilapia fishes have to face in order to survive :
•Struggle against environment.
•Interspecific struggling between tilapia fish and indigenous fish.

3.12 Prepare a list of roles air sacs of pigeon play to fly in the air?
Ans: The following are the roles of air sacs of pigeon to fly in the air:
• Make the birds light to flight easily in the air.
• Regulation of body temperature.

3.13
Structure and function
Indicating the nature of evolution
Based on the above two features establish the concept of analogous organ with the help of proper example?
Ans: Analogous organs is a type of convergent evolution in which the individual have similar funtions but different structures. For example : Bird, Bat and insect have similar functions of flying but the structure of their wings are completely different and this also shows that different individuals have similar function giving an example of convergent evolution.

3.14 Relate the following phenomena with the trend of disturbance in Nitrogen Cycle resulting from different human activities:
Global Warming
Acidification of soil and water of river and lake
Ans: Human activities such as use of fertilizer greatly increase the amount of nitrogen mainly includes oxides of nitrogen (NO_x), ammonia (NH₃) and Nitrous oxide (N₂O) from the aquatic and terrestrial ecosystem and NO_x from fossil fuel and biomass combustion.Nitrous oxide (N₂O) is 300 times more effective than CO₂ as a greenhouse gas. Thus, increased amount of N₂O and other oxides of nitrogen cause global warming. This led to the acidification of downstream fresh water systems like river and lakes.

3.15 Hilsa, Bee, Penguin, Rauwolfia-
Asses which of the causes of endangeredness of the above-mention organisms?
Ans: Rauwolfia is the cause of endangeredness of the above-mentioned organisms.

3.16 Discuss any two roles of People’s Biodiversity Register (PBR) in conserving local biodiversity?
Ans: These are the two roles of People’s Biodiversity Register (PBR) in conserving local Biodiversity:
• To conserve and sustainable use of biodiversity.
• Protection & rehabilitation of threatened species

3.17 Tabulate any of the four activities which are prohibited in a sanctuary following the provisions of Wildfire Act?
Ans: The following are the four activities that are prohibited in a sanctuary:
• Destruction in a sanctuary without permission.
• causing fire is prohibited.
• prohibition of entry into sanctuary with weapon
• Ban on the use of injurious substances.