pls help me out please
Answers
1. Ans Unicellular organisms :These are the living organisms that are made up of only one cell.
Also called single-celled organisms
Example : Amoeba , yeast ,etc.
Multicellular organisms : These are the living organisms that consists of large number of cells
that constitute an organisms
Example : Man , tree, etc.
2. Ans For 15 oscillation it takes 30 sec
For 15 oscillation it takes 30 secFor one oscillation Tme period = 30/15 = 2sec
Frequency = 1 /Time period
/Time period=1/2=0.5 Hz
3. Ans
Musical sound
• It has a pleasuring effect on the ears.
• It is produced by regular periodic vibration of the body.
Noise sound
• It is the displeasing to the ear.
• It is produced by irregular vibration in a material
5. Ans Metamorphosis : It is defined as the process in which an animal’s body structure abruptly changes through cell growth and differentiation.
Metamorphosis take place in frog : -
1)Tadpole is adapted to live life in water only. 2)Tadpole has a long tail which helps it to swim easily in water.
6. Ans In humans, sex is determined by sex chromosomes (XX females, XY males). The X and Y chromosomes harbor dramatically different numbers and sets of genes (about 1,000 genes on the X and only a few dozen genes on the Y), yet they originated from ordinary autosomes during the early evolution of mammals
7. (i) Ans
Consequences of deforestation :
• Increase in temperature and Global Warming.
• Increase in pollution.
• Soil erosion.
(ii)
(a) Ans Biosphere reserves are the protected areas meant for the conservation of plants and animals. It also restores the traditional life of the tribals living in that vicinity. They conserve the biodiversity of that area.
(b) Ans A wildlife sanctuary is an area where animal habitats and their surroundings are protected from any sort of disturbance. The capturing, killing and poaching of animals is strictly prohibited in these regions. They aim at providing a comfortable living to the animals.
(c) Ans A national park is a park in use for conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. ... According to the IUCN, 6,555 national parks worldwide met its criteria in 2006.
