CBSE > Class 08 > Science | CBSE Board | Homework Help

The pressure at which the blood is pumped around the body by the heart is called blood pressure. The two factors which expresses the blood pressure a person are systolic pressure and diastolic pressure. The pressure of blood inside the artery during ventricular systole (contraction) is called systolic pressure and pressure in artery during ventricular diastole (relaxation) is called diastolic pressure. The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg.

0Thank You

ANSWER

Vitro Fertilization

Posted by Sehaj Deep Kaur 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Anuraag Kumar 6 years, 1 month ago

8th class ka science Hindi medium

0Thank You

ANSWER

Tadpoles

Posted by Sehaj Deep Kaur 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Kunal Singh 6 years, 1 month ago

Youngone`s of frog.

0Thank You

ANSWER

External Fertilization

Posted by Sehaj Deep Kaur 6 years, 1 month ago

CBSE > Class 08 > Science

2 answers

Kunal Singh 6 years, 1 month ago

In some animals, like fish and frogs, fertilisation takes place outside the body is called external fertilisation.

0Thank You

Mehak Jain 6 years, 1 month ago

The fertilisation which take place outside the female body

0Thank You

ANSWER

...isa jelly like fluid in the the cell

Posted by Aniket Kumar 6 years, 1 month ago

CBSE > Class 08 > Science

4 answers

Kunal Singh 6 years, 1 month ago

Organelles.

0Thank You

Shubham Kumar 6 years, 1 month ago

Cytoplasm

0Thank You

Mehak Jain 6 years, 1 month ago

Yes

0Thank You

Prasun Pallav 6 years, 1 month ago

Yes

0Thank You

ANSWER

What are weeds how can we control them

Posted by Subedar.Harini Subedar Sarika 6 years, 1 month ago

CBSE > Class 08 > Science

2 answers

Kunal Singh 6 years, 1 month ago

Unwanted plants which grow along with crops are called weeds. Control of weed like trowel,hoe and rake.

0Thank You

Yogita Ingle 6 years, 1 month ago

Undesirable plants that grow along with crop plants are known as weeds. Xanthium, Parthenium, etc. are some common weeds. Weeds compete with the crop for nutrients, light, and space. As a result, crop plants get lesser nutrients, light, and space for their development. This in turn, reduces their productivity. Thus, various weeding methods are employed.
Some important weeding methods are:

Weeds can be controlled using weedicides. It is a chemical, which is sprayed in the fields to kill all available weeds. Weedicides are not harmful to crops.
Tilling before sowing of crops also helps in removing weeds. Tilling uproots the weeds. The best time for the removal of weeds is before they produce flowers and seeds.
The manual method of removing weeds is with the help of a khurpi. It involves regular uprooting or cutting of weeds close to the ground.

2Thank You

ANSWER

Give different effects of current in liquid?

Posted by Kirti Mishra 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Prasun Pallav 6 years, 1 month ago

1.it do es not stop current

2Thank You

ANSWER

Give example to show that friction is both friend and foe

Posted by Saravanan Balu 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Riza Sanjayi 6 years, 1 month ago

Friction is a friend as it helps to hold our pen or pencil. If there is no friction we will slipp while walking. Friction is a foe as it causes wear and tear.

1Thank You

ANSWER

These resources are present in unlimited quantity in nature and are not likely to be exhausted by human activities?

Posted by Deep Thakur 6 years, 1 month ago

CBSE > Class 08 > Science

2 answers

Kunal Singh 6 years, 1 month ago

Nonrenewable resources.

0Thank You

Riza Sanjayi 6 years, 1 month ago

Inexhaustible natural resources

0Thank You

ANSWER

How does an RO system purify water ?

Posted by Khilander Kumar 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Yogita Ingle 6 years, 1 month ago

Reverse Osmosis (RO) is a water treatment process that removes contaminants from water by using pressure to force water molecules through a semipermeable membrane. During this process, the contaminants are filtered out and flushed away, leaving clean, delicious drinking water.

0Thank You

ANSWER

What is vitro fertilisation ?

Posted by Himanshu, Tarun,Sakshi Yadav 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Gaurav Seth 6 years, 1 month ago

It is a method in which ovum collected from a female's body is allowed to fuse with sperm collected from a male's body in an external medium or outside the body of the female.

The fertilisation of an egg that takes place outside the body in a test tine or in any other, apparatus is known IVF or in vitro fertilisation.

1Thank You

ANSWER

Explain why we always hear the thunder a little after we see the flash of lightning

Posted by Anil Chauhan 6 years, 1 month ago

CBSE > Class 08 > Science

4 answers

Unnati Sharma 6 years, 1 month ago

Yes the first answer is ful correct

1Thank You

Harshita Badwal 6 years, 1 month ago

Becaise the speed of light is more rhan speed of sound

0Thank You

Bangtan Army Forever 6 years, 1 month ago

Yes ,the avobe answer is correct ,i approve this answer.

0Thank You

Yogita Ingle 6 years, 1 month ago

we always hear the thunder a little after we are see the flash of lightning because light travel faster than sound.

0Thank You

ANSWER

How the sperm enters in female's ovary

Posted by Samiksha Nimje 6 years, 1 month ago

CBSE > Class 08 > Science

4 answers

Kunal Singh 6 years, 1 month ago

The sperms introduce into the ****** , during intercourse, travel up the ****** and uterus into the Fallopian tube.

0Thank You

Samiksha Nimje 6 years, 1 month ago

See the sperm is in the male and the ova is in the female so how the sperm come out From male and enters in female's ova ???

0Thank You

Samiksha Nimje 6 years, 1 month ago

That i know

0Thank You

Anuranjan Nirala 6 years, 1 month ago

During copulation ***** release sperm in ****** sperm travel through follapion tube in to ovary sometime female follapion tribe's are chock so IVF is use in this condition

0Thank You

ANSWER

Why does a steel ball floats on mercury

Posted by Raashi Chinmayi 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Gaurav Seth 6 years, 1 month ago

The density of the steel balls is greater than the density of the water so they float in water. When the steel balls are placed in mercury then it floats in it because the density of the mercury is greater than the density of the steel balls. So, the steel balls displace the water equal to their weight and hence float.

0Thank You

ANSWER

Which of the following is the best method for preserving milk

Posted by Rahul Shakya 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Samiksha Nimje 6 years, 1 month ago

Pasteurisation

1Thank You

ANSWER

Keywords of chapter 11

Posted by Jaisingh Yadav 6 years, 1 month ago

CBSE > Class 08 > Science

0 answers

ANSWER

What is in vitro fertilization??

Posted by Parul Jain 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Yogita Ingle 6 years, 1 month ago

Vitro fertilization (IVF):

It is a method in which ovum collected from a female’s body is allowed to fuse with sperm collected from a male’s body in an external medium or outside the body of the female.
The zygote so developed is allowed to grow in vitro (i.e.in glass) for about a week and then implanted in the female’s uterus where it further develops as a normal embryo.
A baby born of this technique is often called a ‘test tube’ baby.

1Thank You

ANSWER

Why are forest fires more likely in the hot, dry season than in the rainy and cold season

Posted by K Sidharth 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Meghna Thapar 5 years, 10 months ago

Temperature affects the sparking of forest fires. The sticks, trees and underbrush on the ground receive radiant heat from the sun, which heats and dries potential fuels. Warmer temperatures allow for fuels to ignite and burn faster, adding to the rate at which a wildfire spreads. That is why, forest fires more likely in the hot, dry season than in the rainy and cold season

0Thank You

ANSWER

Why do we blink our eyes?

Posted by Shreya Kumari Gupta 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Radhika Sharma✌️✌️ 6 years, 1 month ago

Every time you blink, your eyelids spread a cocktail of oils and mucous secretions across the surface of the eye to keep your globes from drying out. Blinking also keeps eyes safe from potentially damaging stimuli, such as bright lights and foreign bodies like dust.

0Thank You

ANSWER

Drinking boiled and filtered water

Posted by Saba Khan 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Radhika Sharma✌️✌️ 6 years, 1 month ago

Because boiled and filtered water does not contain any impurities in it which will not harm us

1Thank You

ANSWER

Human heart

Posted by Kavita Kavita 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Meghna Thapar 5 years, 10 months ago

The heart is roughly triangular in shape. It has four compartments called chambers inside it. The upper two chambers of the heart are called atria and the lower two chambers are called ventricles. The atria receive blood from the two main veins. The left atrium is connected to the left ventricle through a valve V1 and the right atrium is connected to the right ventricle through another valve V2. These valves prevent the backflow of blood into atria when the ventricles contract to pump blood out of the heart to the rest of the body because when the ventricles contract, the valves V1 and V2 close automatically so that the blood may not go back into the atria. The job of heart is to pump blood around our body. All the atria and ventricles of the heart contract and relax at appropriate times and make the heart behave like a pump. A sheath of tissue called pericardium protects the muscular heart.

0Thank You

ANSWER

What are drugs

Posted by Aarav Chauhan 6 years, 1 month ago

CBSE > Class 08 > Science

2 answers

Samiksha Nimje 6 years, 1 month ago

The best example is opium ,its a type of a drug which is used to sleep

1Thank You

Seraph ♂ 6 years, 1 month ago

Durgs are that substamce which is made by petrochemicals.

0Thank You

ANSWER

What are drigs

Posted by Aarav Chauhan 6 years, 1 month ago

CBSE > Class 08 > Science

1 answers

Meghna Thapar 5 years, 6 months ago

A drug is any substance (with the exception of food and water) which, when taken into the body, alters the body's function either physically and/or psychologically. Drugs may be legal (e.g. alcohol, caffeine and tobacco) or illegal (e.g. cannabis, ecstasy, cocaine and heroin).

The main categories are:

stimulants (e.g. cocaine)
depressants (e.g. alcohol)
opium-related painkillers (e.g. heroin)
hallucinogens (e.g. LSD)

0Thank You

ANSWER

What is apical (meristem)

Posted by Mayuri Shinde 6 years, 1 month ago

CBSE > Class 08 > Science

2 answers

Sehaj Deep Kaur 6 years, 1 month ago

❓❔❓❔???????❔❓❔❓

0Thank You

Jaikumar Damodar 6 years, 1 month ago

Dont know

2Thank You

ANSWER

Why potato conduct electricity

Posted by Shriyam Singh 6 years, 1 month ago

CBSE > Class 08 > Science

3 answers

Samiksha Nimje 6 years, 1 month ago

Bcoz it contains a certain type of acid called solanine

0Thank You

Samiksha Nimje 6 years, 1 month ago

Becoz its a certain type of acid callrd solanine

0Thank You

Sunil S 6 years, 1 month ago

To be clear, the potato is not, in and of itself, an energy source. What the potato does is simply help conduct electricity by acting as what's called a salt-bridge between the the two metals, allowing the electron current to move freely across the wire to create electricity.

3Thank You

ANSWER

What is meant by pitch

Posted by Sanju Malakar Malakar 6 years, 1 month ago

CBSE > Class 08 > Science