BIOLOGY
1. Explain salient features of multicellular algae· They are non-vascular plants
· Body is float called thallus
· They are classified as ; green algae , red algae and brown algae
· Reproduction is by sexual , asexual and vegetative methods
2. Explain alternation of generation
The process of gametophyte and sporophyte being formed alternatively during life cycle is called alternation of generation
3. Write difference between gametophyte and sporophyte
Gametophyte | Sporophyte |
Produce gametes | Produces spores |
They are larger in number | They are smaller in size |
They have haploid number | They have diploid number |
They contain chloroplast and hence prepare their own food | They donot contain chloroplast and hence depend on gametophyte for food |
Monocot | Dicot | |
Seed | One seed | Two seed |
Leaf | Parallel venation | Reticulate venation |
Root | Fibrous root | Tap root |
Germinations | Below the soil | Above the soil |
Flower | Multiples of 4 or 5 petals | Multiples of 3 |
Vascular bundles | Scattered | In the form of ring |
Special branch bearing cluster of flowers in angiosperms is called inflorescence
6.
Features | Pisces | Amphibians | Repttiles | Aves | Mammals |
Digestive system | Complete | Complete | Complete | Complete | Complete |
Respiration | Gills | Gills, lungs , moist skin | Lungs | Lungs | Lungs |
Heart | 2 Chambered | 3 Chambered | 3 or 4 C Chambered | 4 Chambered | 4 Chambered |
Nervous system | 10 pairs of cranial nerves | 10 pairs of cranial nerves | 12 pairs of cranial nerves | 12 pairs of cranial nerves | 12 pairs of cranial nerves |
Fertilization | External | External | Internal | Internal | Internal |
Oviparous / viviparous | Oviparous | Oviparous | Oviparous | Oviparous | viviparous |
Cold blooded / warm blooded | Cold blooded | Cold blooded | Cold blooded | warm blooded | warm blooded |
· They can be easily grown
· They produce large number of seeds
· They are self-pollinating
8. Explain monohybrid cross with an example
9. Explain dihybrid cross with an example
10. Write difference between phenotype and genotype
Phenotype | Genotype |
It is an expressed character genetically controlled | It is the combination of genes in an organism |
Tall pea plant , dwarf pea plant are phenotype | TT, Tt, tt are genotype |
The deviation from mendilian inheritance is called incomplete dominance
Incomplete dominance takes place when both the genes are equally dominant in heterozygote. Hence phenotype ratio and genotype ration will be same.
12. What are nitrogenous bases (purine and pyrimidine’s)?
Purine and pyrimidine are nitrogenous bases.
Adenine (A) and guanine (G) are purine base
Thymine (T) and cytosine(C) are pyrimidine base.
13. Explain significance of DNA replication
DNA makes copies of itself within the nucleus during interphase stage of cell division. This is called DNA replication.
Significance: a. It carries genetic information
b. It indirectly synthesis proteins.
14. Define gene
Gene is the physical and functional unit of heredity
15. What is recombinant DNA technology?
It is the technique by which genes are manipulated in the laboratory to produce hybrid offsprings.
16. What is cloning?
It is the process of producing similar population of genetically identical individual invitro
17. What is DNA finger printing? Write its application
It is the technique used to identify and analyze the variations in various individual. It involves process called gel electrophoresis.
Application: It is used in forensic science to detect crime suspect
18. What are the applications of biotechnology?
· It is used to synthesis drugs like antibiotics, vaccines, etc.
· It is used in food processing
· To synthesis biopolymers.
19. What are the limitations of biotechnology OR Though biotechnology is boon to mankind it may cause serious threat in future. Why?
· Genetically modified foods are threatening to human and animal health
· It is a question of morality and ethics.
20. What are the cells present in xylem?
· Xylem parenchyma : Helps in lateral conduction of water and storage of metabolic substance
· Xylem fibres: They provide mechanical support and tensile strength
· Xylem vessels: They are elongated dead cells suitable for quick conduction of water
· Xylem tracheid: They are short structure usually found at the leaf tip.
21. What are the cells present in Phloem?
· Phloem parenchyma: They are living cells which perform similar function of parenchyma.
· Phloem fibres: They provide mechanical support and tensile strength
· Sieve tubes: They contain sieve plates through which food passes
· Companion cells: They are living cells which regulate passage of food through sieve tubes.
22. Write a note on epidermis OR Write the function of cuticle
· Epidermis of leaf and stem regulate passage of gases
· Some plants have covering substance called cuticle which control rate of transpiration.
23. Write a note on cardiac muscles
Cardiac muscles are found only in heart. These muscle fibres are elongated, cylindrical and branched. They are involuntary muscles known for high rhythmic contraction and relaxation.
24. Write the function of epithelial tissue
· They help in maintain body temp
· They help in absorbing nutrients
· ciliated epithelium help in movement of materials
· They help in secretion.
25. Write difference between striped muscles and unstriped muscles
Striped muscles | Unstriped muscles |
They are attached to bones , hence called skeletal muscles | They are also called smooth muscles |
They are multinucleated | They are uninucleated |
They are voluntary muscles | They are involuntary muscles. |
Voluntary muscles | Involunatry muscles |
These muscles act according to our will | These muscles do not act according to our will |
They help in movement of limbs | They help in blood circulation , digestion , etc |
Striped muscles are voluntary muscles | Unstriped muscles and cardiac muscles are involuntary muscles. |
It is the reduction of ozone layer in stratosphere layer. It is caused due to release of chlorofluorocarbon (CFC) into atmosphere by human activity.
Effects: It effects’ natural balance of gases.
It affects physiological balance of plants and animals
Prevention: Avoid using equipment’s releasing CFC.
Reduce the use of foam plastic.
28. Write a note on global warming
It refers to rise in average temp of earth’s atmosphere due to effects of greenhouse gases.
It results in: Increase in sea level
It affects both aquatic and land life
It affects crop and food production.
29. Write a note on green house effect
The infrared rays released due to heating of earth by solar radiation are trapped by some gases, which result in increase of atmospheric temperature.
Greenhouse gases are oxides of nitrogen, methane, carbon monoxide, etc.
30. Write a note on acid rain
Precipitation of snow, rain or fog with a PH value less than 5.6 is called acid rain.
Effects: It causes effects to old buildings and monuments
It causes skin allergy and respiratory problems.