How is sound produced in humans Class 8

Chapter 13 Sound Class 8 Notes - Extra Question

  1. How do humans produce sound? The sound produced in the voice box called larynx located at the upper end of the windpipe. 2 vocal cords get stretched across in the voice box. Has a slit, through which air is forced out by the lungs
  2. In this chapter, the students will learn, how sound is produced by a vibrating body, sound produced by humans, how sound propagates through, air and water. Solving the NCERT exemplar Solutions class 8 science chapter 13 sound will help the students to understand the higher-order thinking questions as well as to score good marks in the exam. To.
  3. Sound is a form of energy produced and transmitted by a vibrating matter. It travels in form of waves through matter and moves in to and fro direction
  4. In humans sound is produced by the vioce box or larynx. It is the upper part of the wind pipe. Two vocal cords are stretched across the voice box leaving a narrow slit. When the lungs force air through the slit, it vibrates and produce sound
  5. The pitch is the property of a sound which tells us how high or low a sound is. Now compare the sounds produced by a violin and a human heartbeat. High pitch sounds. Low pitch sounds. You will realize that a violin produces a high pitch sound, while human heartbeat has a low pitch sound

NCERT Exemplar Class 8 NCERT Exemplar Questions Science

  1. g sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are called the malleus, incus, and stapes
  2. Sound is a type of energy made by vibrations. When any object vibrates, it causes movement in the air particles. These particles bump into the particles close to them, which makes them vibrate too, causing them to bump into more air particles. This movement, called sound waves, keeps going until they run out of energy
  3. In simple terms, sound is vibration. The complex internal structure of our ears can respond to the waves produced by vibration, whether in the form of bass drum or an acoustic guitar. When an instrument produces vibrations, it creates oscillating sound waves. Some of these waves are audible to humans, while others are very deep or high-pitched.

Sound Class 8 Extra Questions Science Chapter 13 - Learn CBS

Most humans can hear sounds between 65 Hz and 23 000 Hz. But that doesn't necessarily mean that ultrasonic sounds are comfortable or even safe to listen to! As a result, you produce much smaller sound waves. The effect is similar to dropping a large rock or a small pebble into the water. The louder sound is like the larger splash This video tutorial lesson describes Production and Propagation of Sound. Find similar educational videos @ http://www.wisdomleap.co (i) In humans sound is produced because of vibration of his voice box or larynx. (ii) It is situated at the upper end of windpipe. There are two stretched membranes called vocal cords attached in larynx with a narrow slit between them for passes air. Voice Box in Humans Sound produced by animals . Animals produce a wide range of sounds. Like sparrow, lion, elephant all of them have different sounds. Many animals use lungs to blow air that make their vocal cords vibrate and sound is produced. Lower organisms use their wings to produce buzzing sound. Fish use airbladder to produce sound

Get Notes Here - https://payments.pabbly.com/subscribe/5e2954ad14a2e43f1110d5ef/notes Class: 8thSubject: ScienceChapter: Sound Topic Name: Sound Produced by. When sound is created, sound waves are made. The sound waves travel out from whatever is making the noise the same way that light travels away from the light source. Think about a light bulb. When it is on, the light comes from the light bulb and travels out. This is the same with sound. Last class you made different sounds

Sound chapter 12 class-8 - SlideShar

CBSE Class 8 Science Notes Chapter 13 Sound Sound plays an important role in our daily life. It helps us to communicate with one another and express yourself. Sound is produced by vibrating the objects and it is carried in all directions with the help of a medium NCERT Solutions for Class 8 Science Chapter 13 Sound Topics and Sub Topics in Class 8 Science Chapter 13 Sound: Section Name Topic Name 13 Sound 13.1 Sound is Produced by a Vibrating Body 13.2 Sound Produced by Humans 13.3 Sound Needs a Medium for Propagation 13.4 We Hear Sound through Our Ears 13.5 Amplitude, Time [ A sound produced by objects like drum or alarm clock is carried away from the object to the ears through the air which acts as the medium. The sound produced is in the form of vibration. It first enters the ears through the funnel-shaped outer part of the ear. It moves down through a canal till the eardrum (the thin membrane is stretched tightly) The human voice is produced by the vocal cords. When air is blown from the lungs through the larynx, the vocal cords vibrate at a frequency and produce sound.. In physiology, sound is produced when an object's vibrations move through a medium until they enter the human eardrum. In physics, sound is produced in the form of a pressure wave. When an object vibrates, it causes the surrounding air molecules to vibrate, initiating a chain reaction of sound wave vibrations throughout the medium

How Is Sound Produced? Lesson - Turtle Diar

  1. The decibel level of a sound having the threshold intensity of 10 −12 W/m 2 is β = 0 dB, because log 10 1 = 0. That is, the threshold of hearing is 0 decibels. Table 1 gives levels in decibels and intensities in watts per meter squared for some familiar sounds
  2. Sound Wave Characteristics. After understanding what is sound, let us study the characteristics of the sound wave. The distance between two consecutive peaks or trough is termed as the wavelength of the wave or the period.The number of cycles per unit time is termed as the frequency of the sound.Frequency is measured in cycles per second or Hertz.. The faster an object vibrates, i.e. the.
  3. What is Sound and How is it Produced. Sound is a form of energy that produces the sensation of hearing in our ears. Frequency range of audible sound for human is between 20Hz to 20 KHz; Sound need Material to Travel: You have learnt in previous section that vibrations produce sound. To produce vibrations, we need a material body
  4. Sound G8 6 Videos 00:23 Hours Share Ever heard the annoying sound made by a mosquito near your ears? Ever wondered how these organisms are producing sound? Well, they are able to generate sound by vibrating their wings. That came out as surprise, didn't it? Sound is a wave that is generated due to vibration, Sound G8 Read More

How Do We Hear? NIDC

Class 8 - Science - Sound. When you call up your friend who is standing at a distance, your friend is able to hear your voice. How does the sound travel to her? Can you think of an explanation? Is it possible that the decreasin.... The huge collection of Questions and Answers for academic studies, CBSE school In humans, the sound is produced by the voice box or the larynx. It is situated in the throat. We hope the NCERT Solutions for Class 8 Science Chapter 13 Sound helps you. If you have any query regarding NCERT Solutions for Class 8 Science 13 Sound, drop a comment below and we will get back to you at the earliest Sound chapter 12 class-8 1. Saturday, December 16, 2017 1 CREATED BY - RAVI PRAKASH SINGH FOR CLASS - VIII SUBJECT - PHYSICS (SCIENCE) 2. Sound is a form of energy produce by vibrations. In humans sound is produced by the vioce box or larynx. It is the upper part of the wind pipe. Two vocal cords are stretched across the voice box. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are called the malleus, incus, and stapes. The bones in the middle ear amplify, or increase, the sound vibrations and send them to the cochlea, a snail-shaped structure filled with fluid, in the inner ear A sound wave is both the end product of the speech production mechanism and the primary source of raw material used by the listener to recover the speaker's message. Because of the central role played by sound in speech communication, it is important to have a good understanding of how sound is produced, modified, and measured

how we make sound - VoiceScienceWork

  1. You can measure sounds in dBA yourself with a sound level meter, such as this app made by the National Institute for Occupational Safety and Health.The app can measure sounds from 0 dBA (sounds so quiet you can barely hear them) to whispering (30 dBA), normal conversation (60-70 dBA), and even a jet taking off (140 dBA)
  2. adjust the sensitivity of a sound meter to sounds of different frequencies that closely approximate how the human ear might respond to moderate sound levels in the 1,000 to 4,000 Hz range. The A-weighted sound level is used extensively for measuring community and transportation noises. The Sound Transmission Class (STC), measured i
  3. To play this quiz, please finish editing it. When the temperature is high in a solid object what happens to the vibration of the sound waves. Which sensory organ of the human body is used to detect transmit and transduce soundwaves. The loudest sounds that you can hear are called ultrasonic sounds. Q

Amplitude is the relative strength of sound waves (transmitted vibrations), which we perceive as loudness or volume. Amplitude is measured in decibels (dB), which refer to the sound pressure level or intensity. The lower threshold of human hearing is 0 dB at 1kHz. Moderate levels of sound (a normal speaking voice, for example) are under 60 dB In this lesson, we learned that sound travels in waves called sound waves. These waves vibrate molecules in air, water, and solids. The vibrations of these molecules create sounds Physics of Sound Traveling Waves. Sound is produced when something vibrates. The vibrating body causes the medium (water, air, etc.) around it to vibrate. Vibrations in air are called traveling longitudinal waves, which we can hear. Sound waves consist of areas of high and low pressure called compressions and rarefactions, respectively Living Science Solutions for Class 8 Science Chapter 13 Sound are provided here with simple step-by-step explanations. These solutions for Sound are extremely popular among Class 8 students for Science Sound Solutions come handy for quickly completing your homework and preparing for exams Sounds are made when objects vibrate. The vibrations enter your ear and you hear them as sound. Find out more in this Bitesize Primary KS2 Science guide

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Therefore, ears hear the sounds. When these particles move fast, a high volume of sound is formed. And then, when these particles move slowly, a low volume of sound is produced. If the human ear is within the range of the vibrations, a sound can be heard. Sound waves are also known as pressure waves because the wave moves the particles along. sound of the human voice is produced due to vibrations in the vocal cor ds. When a bir d flaps its wings, do you hear any sound? Think how the buzzing sound accompanying a bee is produced. A stretched rubber band when Fig. 12.4: A beam of light fr om a light sour ce is made to fall on a mirr or. The reflected light is falling on the wall

How is Sound Produced? Phenomenon of Vibration Udemy Blo

What is Sound and How do we Hear it? Let's Talk Scienc

Reproduction Class 8 Science Chapter 9 as per NCERT Book used in CBSE and other Schools. The lesson covers the complete explanation of class 8 Chapter 9 Reproduction. Topics covered are Reproduction, Sexual Reproduction, Asexual Reproduction, Terminology Involved, Male Reproductive system, Female Reproductive system, Fertilization in Humans. A. Vocal fold anatomy and biomechanics. The human vocal system includes the lungs and the lower airway that function to supply air pressure and airflow (a review of the mechanics of the subglottal system can be found in Hixon, 1987), the vocal folds whose vibration modulates the airflow and produces voice source, and the vocal tract that modifies the voice source and thus creates specific.

Production and Propagation of Sound - Science Class 8

A normal human ear can hear a sound only if its frequency lies between 20Hz and 20,000Hz. In other words, a human ear neither hears a sound of frequency less than 20Hz nor a sound of frequency less than 20,000 Hz. Different peoples have different range of audibility. 30 11. Shriller sound has more frequency. 12. Tabla is a musical instrument. 13. The sound could not travel in solid. 14. The pitch of a sound depends in the frequency of the waves. We hope the given NCERT MCQ Questions for Class 8 Science Chapter 13 Sound with Answers Pdf free download will help you

Sound. Waves. Description. This simulation lets you see sound waves. Adjust the frequency or volume and you can see and hear how the wave changes. Move the listener around and hear what she hears. Sample Learning Goals. Explain how different sounds are modeled, described, and produced. Design ways to determine the speed, frequency, period and. Human ear - Human ear - The physiology of hearing: Hearing is the process by which the ear transforms sound vibrations in the external environment into nerve impulses that are conveyed to the brain, where they are interpreted as sounds. Sounds are produced when vibrating objects, such as the plucked string of a guitar, produce pressure pulses of vibrating air molecules, better known as sound.

Sound - Class 8 : Notes - DronStudy

The study of the human perception of sound is called psychoacoustics. Many factors go into hearing, including wave properties, sensory and brain processes. First, the wave has to be made, and it has a specific wavelength and frequency. Then the sound wave reaches the human ear, and is processed through many areas The principle is the same as that for the recorder. However, on the flute the lips fix the outlet for the breath, while on the recorder the windway fixes the outlet for the breath As the breath is directed toward the edge of the embouchure hole, high-pressure sound waves pass through the tube and reach openings such as the end of the foot joint and the sound holes Voice Summary Report. Voice (or vocalization) is the sound produced by humans and other vertebrates using the lungs and the vocal folds in the larynx, or voice box. Voice is not always produced as speech, however. Infants babble and coo, animals bark, moo, whinny, growl, and meow, and adult humans laugh, sing, and cry

Many human-produced sounds in the ocean are intermittent, whereas shipping creates an almost constant rumble in the ocean. Even the motor of a fishing boat creates extra sound underwater. All of these sounds add to overall ocean noise and contribute to the soundscape, which scientists define as the combined sounds made by humans, natural. Why are tuning forks made with definite frequencies in the order 2 5 6, 2 8 8, 3 2 0, 3 4 1, 3 8 4, 4 2 6, 4 8 0, and 5 1 2? View solution Give reasons as to why the sound produced from a stretched string is different from when it is relaxed

Lesson 3 (will carry over two days) Topic: Comparing human and animal sound ranges. Class: Grade 4 Science Description of Lesson: Students will be exploring different animals and the sounds they produce, along with their sound range. A comparison chart will be created to compare the different animals' sound ranges to that of a human Intext Question 1 Page 163 - Explain how sound is produced by your school bell. View Answer NCERT Question 2 - Describe with the help of a diagram, how compressions and rarefactions are produced in air near a source of sound In their House of Sound, Fran Scott and Greg Foot investigate how sound is made and how we hear it. They explain that sound is caused by vibration. If an object vibrates the air particles called. Sound waves are produced due to variations in pressure & density of the medium. • Compression is the portion of the medium where a temporary increase in volume & a decrease in density takes place when a sound wave passes through the medium

Resources Class 8 Extra Questions and Answer Geography Chapter 1 Short Answers Type. Question 1. Describe the term Patent and Technology. Patent is meant by the exclusive right over any idea or invention. Technology is the application of latest knowledge and skill in doing or making things. Question 2 Sound is a form of energy which gives sensation of hearing to us. Sound is produced due to vibration of a body. It is a form of mechanical energy. Sound is produced by: • Vocal cords of human being • Birds and animals • Bell • Vehicles • Musical instruments like guitar, veena, violin, piano, harmonium, flute, shehnai, tabla, drums. Characteristics. Sound is a mechanical wave. The physics of waves helps to explain the process by which sound is produced, travels, and is received. Sound is a wave that is produced by objects that are vibrating. It travels through a medium from one point, A, to another point, B. As is true of all types of waves, specific behaviors, properties.

Sound Produced by Animals: Animals produce a wide range of sounds. Many animals use their lungs to blow air that makes their vocal cords vibrate and sound is produced. Maximum lower organisms use their wings to produce buzzing sound. Fish use the air bladder to produce sound and so on. Sound Class 9 NCERT Book solutions. 1 Coal and Petroleum Class 8 Science Chapter 5 as per NCERT Book used in CBSE and other Schools. The lesson covers the complete explanation of class 8 Chapter 5 Coal and Petroleum.Topics covered are types of natural resources, fossil fuels, destructive distillation, energy and environment

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Sound Class 8 Notes, Question Answers, Explanatio

The skin of the drum vibrates and makes the confetti dance. As the air molecules vibrate against each other, sound waves are formed and the sound of the drums can be heard. Fran explains that the. You can refer to NCERT Solutions for Class 9 Science Chapter 12 Sound to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams. Sound Class 9 MCQs Questions with Answers. Question 1. Note is a sound (a) of mixture of several frequencie Have a glance at the MCQ of Chapter 8 Science Class 10 and cross-check your answers during preparation. Question 1. Assertion: In human beings, the female. play a major role in determining the sex of the offspring

Sound Produced by Humans - Sound Class 8 Science - YouTub

Free PDF Download - Best collection of CBSE topper Notes, Important Questions, Sample papers and NCERT Solutions for CBSE Class 8 Science Coal and Petroleum. The entire NCERT textbook questions have been solved by best teachers for you Ans. School bell starts vibrating when heated which creates compression and rarefaction in air and sound is produced. Related questions A sonar device on a submarine sends out a signal and receives an echo 5 s late

2000 3.8% 36.7% WSJ with clean speech 5000 0.9% 4.5% WSJ with noisy speech (10db SNR) 5000 1.1% 8.6% Clean speech based on trigram sentences 20000 7.6% 4.4% • Humans are at least 5 times better than machines, and far more robust • In the last experiment humans and machines have the same syntactic an A man has a different sound compared to a woman. An adult has a different sound compared to the child and so on. Just like heat, electricity, or light, sound is also a type of energy. When a sound is made by something, it starts vibrating the air molecules, which sends a series of reactions through the air until it reaches our eardrums Human Made Resources. Sometimes different natural resources take the form of a resource only when their original form is changed by humans. Earlier people didn't consider Iron Ore a resource until they learnt the method of extracting iron from this Ore. Natural resources are useful in constructing various things such as vehicles, roads, bridges, buildings and machinery which are considered. The Physics of Sound: How We Produce Sounds. As a given object vibrates or oscillates in air, for example, the air molecules near or around the medium will be moved back and forth in relation to the frequency and force of the vibration. This energy then moves through the air as a pressure wave. If the vibration is strong and slow, like bass.

Sound. Sound is made up of vibrations, or sound waves, that we can hear. These sound waves are formed by objects vibrating (shaking back and forth). Sound waves travel through air, water, and solid objects as vibrations. When they reach our ears, these waves make the delicate skin of the eardrums vibrate. The brain recognizes these vibrations. Sound travels in mechanical waves. A mechanical wave is a disturbance that moves and transports energy from one place to another through a medium. In sound, the disturbance is a vibrating object. And the medium can be any series of interconnected and interactive particles. This means that sound can travel through gases, liquids and solids Part 2: Illustrating Sound = Vibration, Vibration, Vibration. Invite 5 or 6 students to the front of the class to be your volunteers. 1 student is the sound source (holding something that makes a sound, such as a bell). 1 student is the eardrum (holding the drum). 4 students are air molecules between the source and the eardrum What is Sound? Sound is a type of energy made by vibrations. When any object vibrates, it causes movement in the air particles. These particles bump into the particles close to them, which makes them vibrate too causing them to bump into more air particles. This movement, called sound waves, keeps going until they run out of energy The Effects of Sound Waves. Whales produce the loudest low frequency sounds on earth — at around 190 dB (17 to 30 Hz). Close up, the high-intensity calls by blue and fin whales can collapse the lungs and cause death to other living creatures. A car stereo made a world record by pumping out 182 dB of sound that could instantly cause hearing loss

Three more parts of the speech mechanism and organs of speech are the larynx, epiglottis and vocal folds. The larynx is covered by a flap of skin called the epiglottis. The epiglottis blocks the trachea to keep food from going into your lungs when you swallow. Across the larynx are two thin bands of tissue called the vocal folds or vocal cords Students examine the existence of sound by listening to and seeing sound waves while conducting a set of simple activities as a class or in pairs at stations. Students describe sound in terms of its pitch, volume and frequency. They use this knowledge to discuss how engineers study sound waves to help people who cannot hear or talk NCERT Solutions for class 8 all subjects in PDF format free to download updated for session 2021-22. All the steps of solutions are properly described. Language of solution or answers is so easy that every student of 8th standard can understand easily. We are trying to provide the best NCERT Solutions 2021-2022 and study material for class 8

Sound Facts. Learn some interesting facts about sound that you might not have known. Understand how sound waves come from vibrations and how your ears give you the ability to hear them. Find out what the speed of sound is, how sound relates to music, the meaning of acoustics and much more Properties of Sound 8. Pitch -description of how high or low the sound seems to a person Loudness how loud or soft a sound is perceived to be. 9. Loudness of Sound in Decibels Sound Loudness (dbs) Hearing Damage Average Home 40-50 Loud Music 90-100 After long exposure Rock Concert 115-120 Progressive Jet Engine 120-170 Pain 10. KINDS OF SOUND. It's the sound of a swell movie about sound! Learn how pitch, frequency, and vibration influence everything you hear. Shhh...Can you hear that? It's the sound of a swell movie about sound! Learn how pitch, frequency, and vibration influence everything you hear.. The sound is probably most like a modern orchestral flute, which also produces a bright sound, has a long, straight tube, and has a small attack sound when the sound is first produced. The initiation of the sound, called chiff can be made somewhat stronger or weaker depending on how the organist plays the keys, and provides articulation. A postalveolar sound is produced when the blade of the tongue comes into contact with the post-alveolar region of your mouth. Examples of post-alveolar sounds in English are / ʃ, ʒ /. Palatal: Palatal sounds are made with the tongue body (the big, fleshy part of your tongue). The tongue body raises up towards the hard-palate in your mouth.

Lesson Plan: Learn How Sound is Created Education Worl

Introduction to Sound Transmission Class (STC) The amount of sound isolation a wall assembly provides is typically measured as its Sound Transmission Class (STC) rating. The STC rating system looks at the amount of noise mitigation provided by the assembly over a broad range of frequencies and a single number is calculated as its rating. STC. Reproduction in Animals Class 8 Extra Questions Short Answer Questions. Question 1. Explain two modes of reproduction with examples. Answer: There are two modes of reproduction: Sexual reproduction: This type of reproduction takes place by fusion of male and female gametes; e.g., Human beings, mammals like cow, buffalo, etc

Students can solve these Force and Pressure Class 8 MCQs Questions with Answers and assess their preparation level. Force and Pressure Class 8 MCQs Questions with Answers. Solving the Force and Pressure Multiple Choice Questions of Class 8 Science Chapter 11 MCQ can be of extreme help as you will be aware of all the concepts Living Science 2019 2020 Solutions for Class 8 Science Chapter 9 Reproduction are provided here with simple step-by-step explanations. These solutions for Reproduction are extremely popular among Class 8 students for Science Reproduction Solutions come handy for quickly completing your homework and preparing for exams Question: What was the loudest sound ever described by humans? Hint: It was produced by the most famous volcano in recorded history. Answer: In 1883, the Krakatoa volcano in Indonesia erupted and threw ash and stone 300 square miles.The explosive sound from this eruption was heard 3,000 miles away. That's the distance from San Francisco to New York City The human ear can detect a wide range of frequencies. Frequencies from 20 to 20 000 Hz are audible to the human ear. Any sound with a frequency below 20 Hz is known as an infrasound and any sound with a frequency above \(\text{20 000}\) \(\text{Hz}\) is known as an ultrasound. Table 10.2 lists the ranges of some common animals compared to humans

Sound Class 8 Notes Science Chapter 13 - Learn CBS

Cell- Structure and Function - Class 8 : Notes. (i) In the living organisms, Cells are basic structural units. (ii) Cells may be compared to bricks. Bricks are assembled to make a building. Similarly, cells are assembled to make the body of every organism. (iii) It is the basic structural and functional unit of life Sound, a form of energy, is all around us. It stimulates our sense of hearing. Sound is a vibration that travels in waves, spreading outwards from the source of the sound. For humans, hearing is limited to frequencies between about 20 Hz and 20,000 Hz (20 kHz) The amount of energy that is transported by a sound wave past a given area of the medium per unit of time is known as the intensity of the sound wave. Intensity is the energy/time/area; and since the energy/time ratio is equivalent to the quantity power, intensity is simply the power/area. Since the range of intensities that the human ear can detect is so large, the scale that is frequently. Micro-Organisms: Friend And Foe - Class 8 : Notes. (i) Organisms which are too small to be seen by the naked eye, especially a single celled organism is called microorganisms or microbes. (ii) Microorganisms are classified into four major groups- bacteria, fungi, protozoa and some algae. (iii) Viruses are also microscopic Pitch is an important concept when thinking about how humans hear and how the ears work. Sound is made when an object is vibrated, and those vibrations usually transmit to the ears via the air. The faster the vibrations are, the higher the sound. How high or low a sound is to the ear is called its pitch

The pipe organ is the largest musical instrument.These instruments vary greatly in size, ranging from a cubic meter to a height reaching five floors, and are built in churches, synagogues, concert halls, and homes. Small organs are called positive (easily placed in different locations) or portative (small enough to carry while playing).The pipes are divided into ranks and controlled by the. But sound technicians and human rights defenders around the world have disputed this framing, comparing sonic weapons to other controversial dispersal tactics like tear gas and rubber bullets

NCERT Solutions for Class 8 Science Chapter 13 Sound

[Music] how are you listening to this music right now well you might know that your speakers are creating sound and your ears are listening to it but there's a lot more going on over here you see all your speakers are doing right now is vibrating the particles of the air close to it then they vibrate the air molecules close to them and so on and so forth and we call this a sound wave and. It is the male gamete or reproductive cell that plays a major role in the reproduction process in humans and other animals. A motile sperm with a tail also called flagellum is produced by animals and it is known with the name spermatozoa whereas algae and fungi are known to produce non-motile sperm cells called spermatia

10 Lines on Environment: Everything that surrounds us is referred to as the environment. It also includes living, non-living, natural, and human-made things. The natural environment includes trees, gardens, rivers, lakes, air, bushes, and many more. Everyone knows that ancient humans lived closer to the natural environment. Thus, it is believed that ancients are lived for [ What is dark energy? More is unknown than is known — we know how much there is, and we know some of its properties; other than that, dark energy is a mystery — but an important one. Roughly 70% of the Universe is made of dark energy. Dark matter makes up about 25%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter adds up to less than 5. Light 1: This lesson is an introduction to light, preparing students to address issues like those discussed above. This lesson introduces students to the electromagnetic spectrum (focusing on visible light) and the wave nature of light. Light 2: This lesson focuses on the idea that we can see objects because they either emit or reflect light Similar to sonar systems on ships, some whales use sound to detect, localize, and characterize objects.By emitting clicks, or short pulses of sound, these marine mammals can listen for echoes and detect objects underwater.This is called echolocation.Some whales and dolphins use echolocation to locate food. They send out pulsed sounds that are reflected back when they strike a target

Humans are apes (superfamily Hominoidea).The gibbons (family Hylobatidae) and orangutans (genus Pongo) were the first living groups to split from this lineage, then gorillas, and finally, chimpanzees (genus Pan).The splitting date between human and chimpanzee lineages is placed 8-4 million years ago, during the late Miocene epoch, with a more constrained interval 8-7 million proposed by.