SECTION “A” (MULTIPLE CHOICE QUESTIONS)
1. Choose the correct answer for each from the given options:
(i) The tissue which conducts water and salts in plants is
(ii) The sensory Layer of eyeball Is;
(iii) The part of stem which gives rise to leaf is called:
(iv) The number of chromosomes in each cell is:
(v) Typhoid is a disease of:
(vi) Nephrons are connected with:
* Respiratory system
* Nervous system
* Circulatory system
* Excretory system
(vii) The respiratory organs of insects are:
* Flame Cells
* Malpighian tubules
(viii) Which of the following is a gill breather?
(ix) Agraicus is.commonly known as:
* Bread mold
* AII of them
(x) Amoeba moves with the help of:
(xi) Crocodile belongs to class:
(xii) The basic unit of classification is:
(xiii) The seed is a:
* Ripened ovule
* Ripened ovary
(xiv) The fourth whorl of a flower is:
(xv) This vitamin is essential for vision:
* Vitamin A
* Vitamin B
* Vitamin C
* Vitamin 0
SECTION”B” (SHORT-ANSWER QUESTIONS)
NOTE: Answer any 7 questions from this section. Each questions carries 3 marks.
2. Define the following branches of Biology:
(i) Palaeontology (ii). Embryology (c) Genetics
It is the study of plants and animals which lived in remote past and are now found as fossils in rocks.
It is the study of developmental changes which occur from Zygote formation to an organism (adult).
It deals with the study of inheritance including transmission of hereditary character from parents to offspring.
3. Write down any three distinctive characteristics of Phylum Echinodermata.
(i) Echinodermates have rough spiny skin and found only in sea
(ii) They are pentamerous and have a unique water vascular system which pumps the external water through out their bodies.
(iii) They have tube feet which enable them to glide over rocks in water.
(iv) They do not have head, eyes or even brain.
Examples: Starfish, See cucumber.
4. Define Portal System. Name the two kinds of Portal System of frog.
The set of veins, which collect blood from one organ and discharge it into another are called portal veins, and, the system consisting of the veins doing this, is called portal system.
Kinds of Portal System:
There are two kinds of portal system in frog.
(i) Hepatic portal system.
(ii) Renal portal system.
(i) Hepatic Portal System:
Blood from the digestive system is taken to liver by Hepatic portal vein. From liver it enters the post cavil. Blood from hind limbs is collected by abdominal vein & taken to liver.
(ii) Renal Portal System:
The alternate route of blood from the hind limbs is by the way of a renal portal vein. The blood is collected by capillaries in hind·limbs which join to form renal portal vein. It opens into kidneys. From kidneys the blood enters post cavil by renal veins.
5. Write three functions of human skeleton.
FUNCTION OF SKELETON IN MAN:
(i) It provides shape and support to the body.
(ii) It gives protection to vital organs such as lungs, heart· and brain.
(iii) It helps in locomotion.
7. State Lamarck’s Theory of Evolution.
LAMARCKISM OR LAMARCK’S THEORY OF EVOLUTION:
J.B. Lamarck (1744 – 1829), a French biologist, proposed that organisms modify their bodies through use or disuse of organs and these modifications can be inherited by the portents to their offspring’s. According to him the continuous use of any organ would develop that organ while disuse would result in gradual weakening and its ultimate reduction and disappearance in the subsequent generations. Such characters were termed as acquired characters. This ideas about the evolution is known as Lamarck’s theory of evolution or Lamarckism.
8. Define the following and give one example of each.
(i) Herbivores (b) Insectivores (c) Carnivores
(i) Herbivores: is that group in which the animals feed on plants e.g. horse, cattle.
(ii) Carnivores: is group of animals included those, which feed on other animals or their flesh. They have strong sharp teeth e.g. cat, dog.
9. Define Cold Blooded and Warm Blooded animals and give two examples of each.
WORM BLOODED ANIMALS:
Worm blooded animals are those animals who maintain their body temperature constant. Example: Class Aves.
COLD BLOODED ANIMALS:
Cold blooded animals are those whose body temperature changes with that of the surroundings. Example: Class Pisces.
This class of worm blooded animals includes all birds. They have feathers on their body fore limbs are modified into wings and have two legs with claws. They do not have teeth in their mouth their respiratory system is well developed.
This class of cold blooded animals includes all kinds of fishes. Their bodies are spindle shaped to help in. swimming. They have head trunk & a tail. Their bodies are mostly covered with scales. They have fins & breathing organs are gills
11. Write three functions of blood.
The blood during its circulation performs the following functions:
(i) It carries oxygen from the respiratory organs to all parts of the body and brings back carbon dioxide to lungs.
(ii) It carries digested food from the alimentary canal to the places where it is required.
(iii) It brings the waste products from various parts of the body to the organs of exertion.
12. Draw. a neat and labeled diagram of chlamydomonas.
13. Define Photosynthesis and write its chemical equation.
The process by which plants make their food is called photosynthesis. In this process a plant can build sugar by taking carbon. dioxide from air and water from – the soil. Enzymes needed for this purpose are present in the cells and
energy is trapped by chlorophyll from sunlight.
14. Describe any three types of bacteria according to their shape.
There are different shapes of bacteria.
(i) Cocci: (Singular-Coccus = Gr. Kokkos = Berry, rounded). They are spherical and according to cell arrangement they are: Solitary (single) (Monococcus), in pair (Diplococci), in chain (Streptococci), in cluster (Staphylococci) etc. They are non_flagellated.
(ii) Bacilli: (Singular-Bacillus = L, Bakulus = A rod). They are rod shaped. They may be found in pairs (Diplobacillus) or in chains (Streptobacillus) etc. They may be flagellated.
(iii) Spirilla: (Singular-Spirillum = Gr. Sperira = A coil. They are spiral or cork screw shaped (spirillum).
15. Write three differences Angiosperms & Gymnosperms.
16. Write three points of economic importance of Fungi.
Economic importance of Fungi:
(i) Food: A number of edible fungi in the form of mushrooms are a source of nourishing and delicious food. Yeast another kind of fungi is used baking industry. Others are used in brewing and in cheese
(ii) Medicines: Antibiotics like penicillin Chloromycetin, Neomycin are fungi and used for cure and treatment.
(iii) Soil Fertility: Fungi maintain the fertility of soil by decomposing the dead organic matter.
(iv) Fermentation: Fungi cause fermentation by which ethanol; alcoholic beverages and organic acids are prepared.
17. Define Phototropism and Geotropism.
Phototropism: It is the movement of a plant in response to the stimulus of light. Stems grow directly towards light and positively phototropic.Leaves also show positive phototropism. Roots grow away from light.
Geotropism: Geotropism is the movement of plant organs in response to the stimulus of gravity or earth. The roots of plants grow towards soil and are positively geotropic.
18. Write one functions of each of the following:
(i) Root (ii) Stem (iii) Leaf
(i) Root: Root holds the whole plant firmly by going deep into the soil.
(ii) Stem: Stem supports branches and leaves for then various functions.
(iii) Leaf: Leaf performs photosynthesis and transpiration.
19. Define Pollination and write the names of its two kinds.
Pollination: The transfer of pollen grains from the anther to the stigma of a flower is called Pollination. It is of two types.
(i) Self Pollination: Pollen grains are transferred from anther to stigma of same flower.
(ii) Cross Pollination: Pollen grains are transferred from anther to stigma of another flower of same species.
20. State Mendel’s Law of Dominance and the Law of Segregation.
MENDEL’S LAW OF DOMINANCE:
According to this law, ” when a pair of contrasting characters (heterozygous allele pair) is brought together in a cross, only the dominant character will appear in the off spring of F, Le. first filial generation.
MENDEL’S LAW OF SEGREGATION:
The law can be started as follows:
“In individuals, the genes exist in pairs but during the formation of gametes each separates or segregates from the other member of the pair and that each gamete has one and only one of each kind of gene.”
21. Define the following:
(i) Transpiration (ii) Osmosis (iii) Diffusion
(i) TRANSPIRATION: Transpiration is the process by which plant give out extra water from the stomata of their leaves, into the atmosphere.
(ii) OSMOSIS: Osmosis is the process by which root hair absorb water containing mineral salts from the soil.
(iii) DIFFRSION: It is the movement of molecules from the area of higher concentration to the area of lower concentration without any semi permeable membrane between the two.
SECTION’C’ (DETAILED-ANSWER QUESTIONS)
NOTE: Attempt 2 questions from this section.
22. Draw a neat and labeled Digestive system of frog. diagram of the Digestive system of frog.
23. Define Mitosis. Write the names of the four phases of Mitosis. Describe the significance of Mitosis.
MITOSIS: In this type of cell division a parent cell divides into two daughter cells in a way that the number of chromosomes in the daughter cells remains the same as in the parent cell. ”
Mitosis is a continuous process, its karyokinesis can be divided for convenience into four phases which are:
SIGNIFICANCE OF MITOSIS:
Mitosis plays an important role in the life of an organism. It is responsible for development and growth of organisms by increasing exact copies of cells. With little exception all kinds of asexual reproduction and vegetative propagation take” place by mitosis. The production of new somatic cells, such as blood cells depends on mitosis. The healing of wounds, repair of wear and tear within organism is also dependent upon the mitotic division.
24. What are Viruses? Write general characteristics of viruses. Write the names of four viral diseases.
Viruses are the smallest, simplest living organisms. They can only be seen by electron microscope.
Characteristics of viruses:
(1) The simple viruses use the enzymes of the host cell for both their protein synthesis and gene replication; the more complex ones contain upto 200 genes and are capable of synthesizing, through their host many structural proteins and enzymes themselves.
(2) Viruses are either virulent, destroying the cell in which they occur or temperate, becoming integrated into their host genomes and remaining stable there for long periods of time.
(3) Viruses may consist of nucleic acid, capsids, envelopes and tail-fibers. Their nucleic acid may consist of a single or several molecules of DNA or RNA. The smallest viruses have only four genes while the largest have upto two hundreds.
(4) The protein cost that encloses the nucleic acid is called a capsid. It may be of different shapes. Capsid is made up of protein sub units called capsomeres.
(5) The simplest viruses consist of a single molecule of a nucleic acid (DNA or RNA) surrounded by a capsid, which is made up of different protein molecules.
Diseases caused by viruses are:
NOTE: Attempt Two questions from this section. Each question carries 7 marks.
25. Draw a neat and labeled diagram of the T.S. of the root of Brassica.
26. Describe an experiment to prove that oxygen is evolved during photosynthesis. Draw its labeled diagram also.
(1) Take a water plant like Hydria and put it in a beaker.
(2) Put a funnel inverted, over this plant. The stem of the funnel should be short.
(3) Fill a test tube with water and keep it inverted on the stem of the funnel. The level of water in the beaker should be above the upper end of the funnel.
(4) Keep this set-up in sunlight for a few hours.
Bubbles rise up slowly in the test tube and a gas is collected in the upper end of the test tube. On testing this gas with a lighted matchstick it is found to glow.
RESULT: The gas collected is oxygen hence oxygen is given out during photosynthesis.
(27) Define Aerobic respiration. Write its chemical equation. Define anaerobic respiration. Write its chemical in bacteria and in animals.
This is the usual mode of respiration in plants and animals. It takes place in the presence of free oxygen, oxidizing the food completely and releasing the maximum energy, 2827 KJ/mole of glucose. The end-products are carbon dioxide and water. No toxic substances are formed.
Anaerobic respiration also called fermentation takes place in some bacteria, fungi and endoparasites. It takes place in the absence’ of free oxygen, hence, the food is oxidized partially, releasing, a small amount of energy.
In Bacteria And Fungi:
IMPORTANCE OF ANAEROBIC RESPIRATION:
As stated earlier, anaerobic respiration takes place in some fungi, bacteria and endoparasites. Although it yields much less energy in comparison to aerobic respiration, it has an advantage that these organisms can survive without oxygen. Endoparasites especially the gut parasites respire anaerobically as no free oxygen is available.