10TH BIOLOGY IMPORTANT QUESTION & ANSWERS

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

4. Write difference between monocot and dicot

	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

5. What is Inflorescence?
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

7. Why did Mendel Chose pea plant for his experiments?
· 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

11. What is incomplete dominance? Give an illustration
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.

26. Write difference between voluntary muscles and 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.

27. Explain ozone depletion.
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.