The Same video through the LINK
Friday, December 25, 2020
Monday, December 21, 2020
Tuesday, December 15, 2020
Thursday, December 10, 2020
9th Grade Lab Work. Mitosis in Onion Root Tip Cells
Title: Mitosis in Onion Root Tip Cells
Purpose: to better understand the process and stages of mitosis; to prepare your own specimens of onion root in which you can visualise all of the stages of mitosis.
Equipment: =/=/=/=/=
Background: The stages of mitosis
Prophase. During prophase, the chromosomes supercoil and the fibers of the spindle apparatus begin to form between centrosomes located at the pole of the cells. The nuclear membrane also disintegrates at this time, freeing the chromosomes into the surrounding cytoplasm.
Prometaphase. During prometaphase, some of the fibers attach to the centromere of each pair of sister chromatids and they begin to move toward the center of the cell.
Metaphase. At metaphase the chromosomes have come to rest along the center plane of the cell.
Anaphase. During anaphase, the centromeres split and the sister chromatids begin to migrate toward the opposite poles of the cell.
Telophase. During telophase, the chromosomes at either end of the cell cluster begin to cluster together, which facilitates the formation of a new nuclear membrane. This also is when cytokinesis occurs, leading to two separate cells. One way to identify that telophase has begun is by looking for the formation of the cell plate, the new cell wall forming between the two cells.
Procedure:
- Cut the tip 5 to 8 mm from the tip of the freshly sprouted root. Discard the rest of the root.
- Place the cut tip on a clean microscope slide.
- Cut alongside the root tip.
- Add 2-3 drops of iodine stain to the slide.
- Cover the slide with a cover slip or lens paper.
- Squash the slide with your thumb using a firm and even pressure. (Avoid squashing with such force that the cover slip breaks or slides).
- Observe it under a compound microscope in 10x (200x magnification) objective. Scan and narrow down to a region containing dividing cells and switch to 40x (800x magnification) for a better view.
The root tip should spread out to a diameter about 0.5 – 1 cm.
Attention!!! Record your observations in the table provided.
| Name of the Phase | What I saw under the microscope (with X) |
Result: We carried out all the stages of the lab work correctly.
While conducting part … =/=/=/=/=
1. Find and draw a cell showing each stage of mitosis.
=/=/=/=/=
2. What is a distinguishing visible feature of each stage of mitosis?
Prophase: =/=/=/=/=
Metaphase: =/=/=/=/=
Anaphase: =/=/=/=/=
Telophase: =/=/=/=/=
Conclusion: In part … =/=/=/=/=
In part … =/=/=/=/=
=/=/=/=/=
Point proven.
Tuesday, December 8, 2020
Monday, December 7, 2020
Thursday, November 26, 2020
Wednesday, November 18, 2020
Nervous System for 8ths. Reflexes. Dreams.
 |
| Horizontal section of the Head of an adult female |
NS 3. Reflexes. Dreams.
Learning Outcomes
Content: to Identify the anatomical and functional differences between types of reflexes; to learn theories of why do we dream.
Language: to be able to explain somatic and autonomic reflexes control.
ЦРФЕ ВЩ НЩГ ЛТЩЦ ФИЩГЕ КУАДУЧУЫ,
1 (pair work). Answer questions after reading the text below.
True or False. Correct the false sentences. Use the the text below.
A___The medulla controls the autonomic system.
B___Autonomic reflexes are more specific.
C___Somatic reflexes are more specific.
2 (individual work). Answer the questions using the text below.
- What are differences between autonomic and somatic reflexes?
- What are the functions of medulla in terms of autonomic control?
Example of autonomic reflex: “The pupillary light reflex begins when light hits the retina and causes a signal to travel along the optic nerve. This is visual sensation, because this reflex is simply sharing the special sense pathway. Bright light hitting the retina leads to the parasympathetic response, through the eye nerve, which stimulates the circular fibres of the iris to contract and constrict the pupil. When light hits the retina in one eye, both pupils contract. When that light is removed, both pupils dilate again back to the resting position. When the stimulus is presented to only one eye, the response is to both eyes”. The same is not true for somatic reflexes. If you touch a hot radiator, you only pull that arm back, not both. Central control of autonomic reflexes is different than for somatic reflexes. The hypothalamus, along with other CNS locations, controls the autonomic system.The medulla (продолговатый мозг) contains cells referred to as the cardiovascular centre, which controls the smooth and cardiac muscle of the cardiovascular system through autonomic connections.
3 (pair work). This is the key vocabulary for the DREAMS video. Do you know meaning of these words and phrases? Use a dictionary to match the words with their translation.
research
persistence
nightmare
conscious
repression
maze
napping
to dump
rehearse
4 (individual work). Answer questions after watching the video (https://goo.gl/nBLLc5).
- List the theories of why do we dream.
- Why is it so difficult to come up with a single, definitive theory about why we dream?
- Which theory (or theories) of dreaming do you believe is the best explanation for why we dream? Please explain why you think so.
Tuesday, November 17, 2020
NS 2. BYOD lesson. 8th Grade
Title: The Nervous System 2
Learning Outcomes
Content: to Identify the anatomical and functional divisions of the nervous system; to relate the functional and structural differences between SNS and ANS.
Language: to list the basic functions of the SNS and ANS; to recall main events in reflex
1 (individual work). Match the given words with the numbers on the picture by using information from last lesson.
- Cell Membrane
- Axon
- Synapse
- Cell Body
- Dendrites
2 (pair work). True or False. Correct the false sentences. Use the text below.
A___We can control a movement of stomach by using the SNS.
B___Control of adrenaline secretion happens by ANS.
C___ANS is controlled by CNS.
D___We feel something by our CNS and PNS as well.
3 (individual work). Answer the questions using text below.
- What are functions of somatic nervous system?
- What causes small intestine to move?
4 (team work). Discuss your answers.
The nervous system can also be divided on the basis of how it controls the body. The somatic nervous system (SNS) is responsible for functions that result in moving skeletal muscles. Any sensory or integrative functions that result in the movement of skeletal muscle would be considered somatic. The autonomic nervous system (ANS) is responsible for functions that affect cardiac or smooth muscle tissue, or that cause glands to produce their secretions. Autonomic functions are distributed between central and peripheral regions of the nervous system. The sensations that lead to autonomic functions can be the same sensations that are part of initiating somatic responses. Somatic and autonomic integrative functions may overlap as well!
5 (individual work). Write a story using information from the picture “How reflex works”.Friday, November 13, 2020
Thursday, November 12, 2020
Monday, November 9, 2020
8th Grade BYOD lesson. Nervous System 1
 |
|
The structures of the PNS are referred to as ganglia and nerves, which can be seen as distinct structures.
|
The Nervous System. General Structure
Learning Outcomes
Content: to Identify the anatomical and functional divisions of the nervous system; to relate the functional and structural differences between grey matter and white matter structures of the nervous system to the structure of neurons.
Language: to be able to list the basic functions of the nervous system.
1 (team work). Explain this text to your group after reading the paragraph. Check if you understand whole!
The nervous system can be separated into divisions on the basis of anatomy and physiology. The anatomical divisions are the central nervous system (CNS) and peripheral nervous systems (PNS). The CNS is the brain and spinal cord. The PNS is everything else. The brain is contained within the skull, and the spinal cord is contained within the vertebral column. The peripheral nervous system is named peripheral because it is on the periphery—meaning beyond the brain and spinal cord. Functionally, the nervous system can be divided into those regions that are responsible for sensation, those that are responsible for integration, and those that are responsible for making responses. All of these functional areas are found in both the central and peripheral parts.
Nervous tissue presents in both the CNS and PNS and contains two basic types of cells: neurons and glial cells. A glial cell provides basic structure of tissue that supports the neurons and their activities. A neuron is more functionally important in terms of the communicative function of the nervous system. To describe the functional divisions of the nervous system, it is important to understand the structure of a neuron. Neurons are cells and therefore have a cell body but they also have extensions of the cell; each extension is generally referred to as a process. There is one important process that every neuron has called an axon, which is the fiber that connects a neuron with its target. Another type of process that branches off from the cell body is the dendrite. Dendrites are responsible for receiving most of the input from other neurons. Looking at nervous tissue, there are regions that predominantly contain cell bodies and regions that are largely composed of just axons. These two regions within nervous system structures are often referred to as grey matter (the regions with many cell bodies and dendrites) or white matter (the regions with many axons). The white matter is white because axons are insulated by a fat-rich substance called myelin.
 |
| Multipolar Neuron 2 (individual work). Fill in the blanks by using text above. |
Structure
|
Function
|
glial cell
|
|
communicative function of the nervous system
|
|
white matter
|
|
process that branches off from the cell body |
3 (individual work). Fill in the blanks by using words and phrases below.
spinal cord
physiology
brain
PNS
CNS
sensation
generating responses
anatomy
grey matter
physiology
brain
PNS
CNS
sensation
generating responses
anatomy
grey matter
The nervous system can be separated into divisions on the basis of (A)___ and (B)___. The CNS is the (C)___ and (D)___. The (E)___ is everything else. Functionally, the nervous system can be divided into those regions that are responsible for (F)___, those that are responsible for integration, and those that are responsible for (G)___. All of these functional areas are found in both the central and peripheral anatomy.
Nervous tissue can also be described as (H)___ and white matter on the basis of its appearance in tissue. These descriptions are more often used in the (I)___.
HW (individual work). Write summary after watching the video.
It is an Experiment BRO: DNA Extraction from ... << 9-10th Grades only >>
DNA is the genetic (hereditary) material in all cells. The experiment described below allows you to take DNA from fruit (onion in this case).
To understand the important principles behind this step, it is not essential to do this experiment at this stage or, in fact, at all. If you are not able to carry out this experiment, read through the details below and try to work out why the procedure works in the way it does - a few questions have been posted at the end of the method to help you think about this.
If you are studying this course with other people, you might want to think about doing the experiment together
If you do plan to carry out this experiment, you will need to read the instructions carefully and do some planning before starting it.
Materials required
For this experiment you will need:
- Fruit – Kiwi, Strawberries, Banana, and Onion all work well!
- 5 g washing up liquid
- 2 g salt
- 100 ml tap water
- 100 ml of ice cold alcohol (isopropyl alcohol can usually be found at the pharmacists); put in a freezer for at least 30 mins before starting the experiment
- Access to hot water - about 60 °C
- Sieve or coffee filter paper
- Two glass beakers (or old jam-jars)
- Several bowls of different sizes, including a large bowl for making a water bath
- Safety spectacles - if desired
Experiment to purify DNA from fruit
Step 1: Mash up the fruit of your choice in a bowl. Onion works well by the way. (Remove the skin, we just want the insides!)
Step 2: In a separate bowl, mix the washing up liquid, salt and tap water. Stir gently trying to avoid making too many bubbles in the mixture. This is your extraction buffer.
Step 3: Add the fruit to the extraction buffer and mix again. Mash your fruit sample as much as you can, but again, try to avoid making too many bubbles.
Step 4: Make a water bath with a temperature of about 60 °C. (A large washing up bowl works well for this.) Leave the fruit extraction mixture to incubate for 5-10 minutes.
Step 5: After 5-10 minutes, filter your fruit mixture through a fine sieve. This will remove all the solid material that you don’t want. You should be left with a clear(ish) liquid.
Step 6: Take the ice cold alcohol and very slowly, drop by drop, pour it down the inside of the container with your fruit mixture. What you want to do is produce a layer of the alcohol floating on top of the fruit mixture.
Step 7: At the interface between the alcohol and the fruit mixture, you should see a white cloud-like substance forming. Use a hook (a bent paperclip would work) to slowly draw the DNA up and out of the solution.
Questions to think about
- Look at each step of the protocol. What are the different steps and reagents (washing-up liquid, salt, water, alcohol) used for in the experiment?
- How are you able to see the DNA?
- Do you think that the sample you have prepared is “pure DNA”?
Saturday, October 31, 2020
Friday, October 30, 2020
Wednesday, October 28, 2020
9th Grade. Nucleic Acids
DNA & RNA (Nucleic Acids)
Learning Outcomes
Content: to be able to explain different roles of DNA and RNA in the cell;
to be able to explain relationship between the DNA, RNA and protein molecules in the cell.
Language: to be able to use specific vocabulary in explaining molecules in your body; clearly and concisely summarise facts and describe their interrelationships.
1 (team work) Answer the question: ‘What is DNA and WHY do we need it?’
2 (individual work) Answer the question after reading the text. ‘What role does complementary base pairing play in the functions of nucleic acids?’
If the primary structure of polypeptides determines a protein’s shape, what determines primary structure? The amino acid sequence of a polypeptide is programmed by a discrete unit of inheritance known as a gene. Genes consist of DNA, which belongs to the class of compounds called nucleic acids. Nucleic acids are polymers made of monomers called nucleotides.The two types of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), enable living organisms to reproduce their complex components from one generation to the next. Unique among molecules, DNA provides directions for its own replication. DNA also directs RNA synthesis and, through RNA, controls protein synthesis; this entire process is called gene expression.A gene’s meaning to the cell is encoded in its specific sequence of the four DNA bases. DNA molecules have two polynucleotides, or “strands,” that wind around an imaginary axis, forming a double helix. In base pairing, only certain bases in the double helix are compatible with each other. Adenine (A) in one strand always pairs with thymine (T) in the other, and guanine (G) always pairs with cytosine (C). Note that in RNA, adenine (A) pairs with uracil (U); thymine (T) is not present in RNA.
3 (individual work). Do you know meaning of the words and phrases in the video? Use a dictionary to match the words with their translation.
blueprint
to line up
sequence
noodle
4 (individual work). Answer questions after watching the DNA & RNA video (https://goo.gl/FusGSw).
- How can a DNA act as a blueprint for something as complex and wonderful as a dog?
- Explain the chain of events from DNA molecule to the protein.
5 (pair work). Construct a table that organises the following terms, and label the columns and rows.
Monosaccharides Fatty acids Polypeptides Triacylglycerols
Polynucleotides Polysaccharides Amino acids Nucleotides
8th Grade small Online quiz
Hey everyone. This is the last opportunity to grab some grade.
Title: Bones and Muscles Quiz
Purpose: to enjoy and get more knowledge and practical skills
Quiz: LINK is here
Tuesday, October 27, 2020
Monday, October 26, 2020
The Human Muscles. 8th Grade lesson
Hey guys. Here is the new lesson on Muscles. Enjoy!
Vocabulary:
within
cardiac
circulatory system
follicle
vessel
striation
branched
to contract
pacemaker
spindle
The Human Muscles
Learning Outcomes
Content: to be able to recall different types of muscle;
to be able to explain the function and structure of skeletal, cardiac muscle, and smooth muscle
Language: to be able to describe the function of each category of muscle
1 (pair work). Which element is important in contraction of muscle? Can you think of other things affecting your muscles?
- sodium (Na+) 2. calcium (Ca++) 3. potassium (K+)
2 (individual work). True or False. Correct the false sentences. Use the text below.
A___There can be four types of muscles.
B___Walls of small intestine mainly made of a smooth muscle.
C___Pacemaker cells are found only in the heart.
D___Striated muscles work using two types of proteins: actin and myosin.
E___Skeletal and smooth muscle cells have one nucleus.
3 (individual work). Answer the questions.
- What are functions of skeletal muscles?
- What are differences between cardiac and smooth muscles organisation?
4 (team work). Discuss your answers.
Muscle is the tissue in human that allows active movement of the body or materials within the body. There are three types of muscle tissue: skeletal muscle, cardiac muscle, and smooth muscle. Most of the body’s skeletal muscle produces movement by acting on the skeleton. Cardiac muscle is found in the wall of the heart and pumps blood through the circulatory system. Smooth muscle is found in the skin, where it is associated with hair follicles; it is also found in the walls of internal organs, blood vessels.
Skeletal muscles maintain posture, stabilise bones and joints, control internal movement, and create heat. Skeletal muscle fibers are long and cells have many nucleuses. Muscle fibers are made of myofibrils. The striations are created by the organisation of actin and myosin resulting in the banding pattern of myofibrils.
Cardiac muscle is striated muscle that is present only in the heart. Cardiac muscle fibers have a single nucleus, are branched, and joined to one another by intercalated discs to hold the fibers together when the heart contracts. Contraction in each cardiac muscle fiber is triggered by Ca++ ions in a similar manner as skeletal muscle. Pacemaker cells stimulate the sudden contraction of cardiac muscle as a functional unit.
Smooth muscle is found throughout the body around different organs and tracts. Smooth muscle cells have a single nucleus, and are spindle-shaped. Smooth muscle can be stimulated by pacemaker cells, by the autonomic nervous system, by hormones, suddenly, or by stretching.
5 (individual work). This is the key vocabulary for the Muscles video. Use a dictionary to match the words with their translation.
to propel
to blink
thump
bundle
cilia
complementary
buccinator
to spread
6 (individual work). Answer questions after watching the Muscles video (https://goo.gl/gCc2qy)
A. Describe the functional difference between fast and slow twitch muscles.
B. What benefits does the muscular system provide, other than just helping you to move?
And watch THIS ONE at home
9th Grade. Nucleic Acids
Hey everyone. Small story on DNA first. Then video test. Enjoy!
Life’s Enigma Code
In the mid-to-late 1940s, scientists began to suspect that the molecules that are responsible for heredity were not proteins, but in fact DNA, short for deoxyribonucleic acid. But how could a molecule long considered to be simple and inert hold the secret of life? The Nobel Prize in Physiology or Medicine in 1962 was awarded to James Watson, Francis Crick and Maurice Wilkins for their discovery of the molecular structure of DNA, which helped solve one of the most important of all biological riddles.
Wilkins and his colleague Rosalind Franklin provided the key X-ray diffraction patterns that Watson and Crick used, as well as information from many other scientists, to build the definitive model of DNA’s structure. The structure, as simple and elegant as it is profound, shows that two long strands of DNA run in opposite directions and spiral around one another in the shape of a double helix. Another vital element in the structure is that four organic bases – known as adenine, thymine, cytosine and guanine – are paired in a specific manner between the two helices in such a way as to provide a natural scaffold for the two strands.
Watson and Crick’s structure of DNA could also explain how information is transferred in living material. The specific base pairing facilitates the perfect copying facility for heredity, while the specific order of bases forms the blueprint for the sequence of amino acids in a protein. DNA molecules can ‘unzip’ into two separate strands, and when the cell’s machinery creates matching strands, the specific pairing between the bases ensures that you get two faithful copies where you had one before. Watson and Crick’s paper revealing the structure, published in Nature on 25 April 1953, contains perhaps one of scientific literature’s most famous understatements: “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”
(This was originally posted on https://www.nobelprize.org/prizes/medicine/1962/speedread/)
Thursday, October 22, 2020
9th Grade. Organic molecules lesson. Proteins
Proteins
Learning Outcomes
Content: to be able to explain different structures and functions of proteins.
Language: to be able to use specific vocabulary in explaining proteins in your body.
Vocabulary
enzymes
carrier
side chain
polypeptide
to denaturate
1 (pair work). Which of these things are proteins? Can you think of other examples?
1 egg-white 2 hemoglobin 3 green leaf
2 (individual work). True or False. Correct the false sentences. Use the text below.
1___Proteins are made of nucleic acids.
2___Function of the protein changes with the shape.
3___Amino acids differ from each other in the amino groups.
4___All amino acids have carboxyl group and amino group.
5___Usually enzymes are proteins.
3 (individual work). Answer questions.
A. What is an amino acid?
B. What are differences between four levels of proteins?
Proteins are a class of macromolecules that perform a diverse range of functions for the cell. They help in metabolism by providing structural support and by acting as enzymes, carriers, or hormones. The building blocks of proteins (monomers) are amino acids. Each amino acid has a central carbon that is linked to an amino group, a carboxyl group, a hydrogen atom, and an R group or side chain. There are 20 commonly occurring amino acids, each of which differs in the R group. Each amino acid is linked to its neighbours by a peptide bond. A long chain of amino acids is known as a polypeptide.Proteins are organised at four levels: primary, secondary, tertiary, and quaternary. The primary structure is the unique sequence of amino acids. The local folding of the polypeptide to form structures such as the α helix and β-pleated sheet makes the secondary structure. The overall three dimensional structure is the tertiary structure. When two or more polypeptides combine to form the complete protein structure, the configuration is known as the quaternary structure of a protein. Protein shape and function are linked; any change in shape caused by changes in temperature or pH may lead to protein denaturation and a loss in function.
4 (individual work). This is the key vocabulary for the Proteins. Do you know meaning of these words and phrases? Use a dictionary to match the words with their translation.
to coil
to denature
to spin
to fold
to dissolve
velocity
to untangle
5 (individual work). Answer questions after watching the Proteins video
6 (team work). Discuss answers with your team.
- Why would large proteins be harder to untangle and refold than smaller ones?
- Explain why raw egg white is liquid while boiled egg white is solid and bouncy?
Subscribe to:
Posts (Atom)