Living Beings

Question 1

bacteria and its types

Answer 1

bacteria are the most priitive unicellular and microscopic plant organisms. its type are:

• coccus (spherial bacteria: diplococci)
• spiral bacteria ( spirillium)
• rod -shaped bacteria ( bacillus: escherichia)
• comma shaped bacteria ( vibrio: vibrio cholera)

Question 2

structure of bacteria

Answer 2

the cell of bacteria consists of a non living cell- wall ans a thin living membrane calle dplasma mambrane.

Question 3

charecteistics of bacteria

Answer 3

• they don’t have well developed nucleus.
• cell wall is present in them
• they may live alone or in colonies
  they reproduce asexually by fission.

Question 4

advantages and disadvantages of bacteria

Answer 4

advantages: they are used for makign medicines like anibiotics.
- they help in digestion og food.
- some bacterias increase fertility in soil.
disadvantages: cause diseases in plants and animals
- they spoil food, milk, fruits and more
- they release toxins into food which causes food poisoning.

Question 5

viruses and its types

Answer 5

viruses are sub- microscopic parasites that cause various diseases in plants and animals.
types: plant virus, animal virus and bacteriophage

Question 6

living and non-living properties of viruses

Answer 6

living properties: they contain genetic material like DNA, they reproduce inside a host cell, they have and transmit hereditary charecteristics to their offspring.

non liviing properties: dont have cellular structure, dont perform metabolic activities

Question 7

bacteriophages

Answer 7

the cirus which attacks bacteria is called bacteriophage virus.

Question 8

modes of transmissin

Answer 8

• through air, water and food
• through direct contanct with the infected
• through the droplets while coughing or sneezing
• through mosquito, houseflies, etc

Question 9

fungi and its charecteristis

Answer 9

fungi are the plants without chlorophyll. they many be unicellular or multicellular.
charecteristics:
- donot contain root, stem and leaves.
- chlorophyll is absent in them.
- they reproduce asexxually be budding, sporulation or fragmentation.

Question 10

advantages and disadvantages of fungi

Answer 10

advantages: they act on dead and decayed bodies.
- fungi like mushrooms provide nutrition.
- fungi like yeast are used in bakery and wine industries.
- some fungi are used for making medicine.

Question 11

modification of roots and its example

Answer 11

• for storage of food: raddish, turnip, carrot,etc.
• for mechanical suppoet: banyan, bamboo, maize,etc.
• for vital functions: hydrilla, water hyacinth, etc

Question 12

modification of stem and its example

Answer 12

• underground modification: potatoes, onions, colacasia
• sub-aerial odification: grass, fern, etc.
• aerial modification: aloe vera, cactus, cucumber, etc

Question 13

modification of leaf and its example

Answer 13

• plants like cactues, barberry, etc. have thorns in their leaves for protection.
• plants like pitcher plants, venus fly-trap have modified their leaves for catching insects.
• cactus, prickly pear have modified into spine to reduce loss of water.
• pea plants have modified their leaves unto tendrill for support.

Question 14

seed and its stucture

Answer 14

the matured ovule that germinates into a new plant is called seed. a seed has 3 major parts. they are: embryo, endosperm/cotyladons, seed coat.

Question 15

types of seed

Answer 15

monocot: the seed which only consists of only one cotyledon or seed leaf is called monocot seed.
dicot: the seed having two cotyledons or seed leaves is called dicot seed.

Question 16

function and dispersal of seed

Answer 16

• functions: helps in sexual reproduction in flowing plants.
  -help to store food.
• seed coat protects the embryo.
  dispersal of seed: the transport or movement of seeds away from the parent plant is called dispersal of seed.
• by wind
• by water
• by explosion of fruits
• by animals and birds

Question 17

germination of seed

Answer 17

the process by which an embryo of a seed grows into a seedling is called the germination of seed.

Question 18

flower and its parts

Answer 18

flower is colorful and the most attractive part of a flowring plant, a complete flower consists of 4 parts: calys, corolla, androeciu and gynoeciym

Question 19

pollination and its types

Answer 19

pollination is the tranfer of pollen granis from anter to stigma of the same flower or different flower.
self pollination: the transfer of pollen grains from the anther to stigma of the same flower.
cross pollination: the transfer of pollen grains from the anther of one flower of a plant to stigma of a flower of another plant of the same species.

Question 20

fertilization

Answer 20

the process of fusion of a male gamete and a female gamete to form a zygote is called fertilization.