The cell and tissues
Class 9 Science · Biology · 33 questions with answers
Class 9 biology is marked on named structures and on where they are found. 'A supporting tissue' is half an answer; 'sclerenchyma, which is dead and lignified, and gives the coconut husk its strength' is a whole one. These questions ask for the name, the property and the location every time, because that is the shape the paper wants.
- Names each organelle and states its specific function
- Distinguishes the three simple plant tissues by structure and role
- Distinguishes xylem from phloem in what they carry and which is living
- Names the four animal tissue types with an example of where each is found
Exercise 1 of 3 · 10 questions
Name the organelle, and say what it does.
Write the answer · Warm-up
Here’s one done for you
Mitochondria release energy as ATP, and the detail worth adding is that they have their own DNA and ribosomes. That extra clause is what turns a one-mark answer into a two-mark one, and it is a fact the paper asks about directly. In Class 9 biology, the specific detail is nearly always where the second mark lives.
- 1)Releases energy for the cell and has its own DNA
- 2)Called the suicide bags of the cell
- 3)The site of protein synthesis
- 4)Modifies, packages and stores substances made by the cell
- 5)Controls what enters and leaves the cell
- 6)A network of membranes that transports material inside the cell
- 7)The organelle that contains the chromosomes
- 8)The fluid-filled space that gives a plant cell its turgidity
- 9)The rigid outer layer found in plant cells but not animal cells
- 10)The plastid that stores starch
Answers
- 1) Mitochondria. They release energy in the form of ATP, and they carry their own DNA and ribosomes, which is why they can make some of their own proteins.
- 2) Lysosomes. They contain digestive enzymes that break down worn-out organelles, and can burst to digest the whole cell when it is damaged.
- 3) Ribosomes. They are found free in the cytoplasm and attached to the rough endoplasmic reticulum.
- 4) The Golgi apparatus. It also forms lysosomes and is involved in making complex sugars.
- 5) The plasma membrane. It is selectively permeable, allowing some substances through and not others.
- 6) The endoplasmic reticulum. Rough ER carries ribosomes and makes protein; smooth ER makes fat.
- 7) The nucleus. It controls the cell's activities and carries the information passed to daughter cells.
- 8) The vacuole. Water in it presses out on the cell wall, which keeps the plant firm.
- 9) The cell wall. It is made of cellulose and gives the cell its fixed shape and support.
- 10) The leucoplast. It is a colourless plastid used for storage.
Exercise 2 of 3 · 11 questions
Name the plant tissue and give one place it is found.
Write the answer · Guided
Here’s one done for you
Collenchyma is the flexibility tissue - living, with corners thickened, found in leaf stalks and young stems. Note that all three simple tissues are best remembered by what they do rather than by what they look like: parenchyma packs, collenchyma bends, sclerenchyma stiffens. A child who has those three verbs can reconstruct the whole comparison table without having learned it.
- 1)Living, thin-walled packing tissue that fills most of the soft parts of a plant
- 2)Living tissue with corners thickened, giving flexibility
- 3)Dead tissue with lignified walls, giving strength and stiffness
- 4)Carries water and minerals upward, and is mostly made of dead cells
- 5)Carries food in both directions, and is living except for one component
- 6)The tissue at the tip of a root or shoot where growth in length happens
- 7)The tissue that adds girth to a stem, found in the cambium
- 8)Dead tissue with thick lignified walls, found in the husk of a coconut
- 9)The outermost protective layer of a leaf, bearing stomata
- 10)The tissue that stores food in fleshy fruits
- 11)The tissue that forms cork on an old stem
Answers
- 1) Parenchyma - found throughout stems, roots and leaves. When it contains chlorophyll it is called chlorenchyma; with large air spaces in aquatic plants it is aerenchyma, which aids buoyancy.
- 2) Collenchyma - found in the stalks of leaves and just below the epidermis of young stems, letting them bend without breaking.
- 3) Sclerenchyma - found in the husk of a coconut, the stems of many plants, and around vascular bundles.
- 4) Xylem - made of tracheids, vessels, xylem parenchyma and xylem fibres.
- 5) Phloem - made of sieve tubes, companion cells, phloem parenchyma and phloem fibres, of which only the fibres are dead.
- 6) Apical meristem. Lateral meristem increases girth and intercalary meristem is found at the base of leaves or internodes.
- 7) Lateral meristem. It divides to increase the thickness of stems and roots.
- 8) Sclerenchyma. It is dead at maturity and gives hardness and strength.
- 9) Epidermis. It protects the leaf and its stomata control gas exchange and water loss.
- 10) Parenchyma. It is living, thin-walled and used for storage.
- 11) Cork cambium (phellogen). The cork it makes is impermeable and protects the stem.
Exercise 3 of 3 · 12 questions
Name the tissue type and give one place it is found in the body.
Write the answer · Practice
Here’s one done for you
Ligament connects bone to bone and tendon connects muscle to bone - and these two are swapped more often than anything else in the chapter. The way to keep them apart is the property: a ligament is elastic, because joints need to move; a tendon is strong and much less flexible, because it has to transmit a pull without stretching. The function explains the property, which is what the paper asks about.
- 1)Covers the surface of the body and lines its internal organs
- 2)Connects bone to bone
- 3)Connects muscle to bone
- 4)A fluid connective tissue
- 5)Muscle that we control at will
- 6)Muscle found only in the heart, which never tires
- 7)Carries messages rapidly from one part of the body to another
- 8)Muscle found in the walls of the stomach and intestine
- 9)The tissue that stores fat beneath the skin
- 10)The tissue that forms the framework of the ear and the nose tip
- 11)The tissue that lines the kidney tubules
- 12)The cells that carry oxygen in the blood
Answers
- 1) Epithelial tissue - found in the skin, the lining of the mouth, the alveoli and the kidney tubules.
- 2) Ligament - a connective tissue that is strong and elastic.
- 3) Tendon - a connective tissue with great strength but limited flexibility.
- 4) Blood - the plasma is the matrix, carrying red cells, white cells and platelets.
- 5) Striated or voluntary muscle - found attached to bones, which is why it is also called skeletal muscle.
- 6) Cardiac muscle - involuntary and rhythmic, contracting and relaxing throughout life without fatigue.
- 7) Nervous tissue, made of neurons - found in the brain, spinal cord and nerves.
- 8) Smooth (unstriated) muscle. It works involuntarily and does not tire quickly.
- 9) Adipose tissue, a connective tissue. It stores fat and acts as an insulator.
- 10) Cartilage, a connective tissue. It is firm but flexible.
- 11) Cuboidal epithelium. It provides mechanical support and takes part in absorption and secretion.
- 12) Red blood cells, part of blood, which is a fluid connective tissue.
While your child works
- Every biology answer here needs a name, a property and a location. Ask for all three.
- Parenchyma packs, collenchyma bends, sclerenchyma stiffens. Three verbs replace a whole comparison table.
- Ligament and tendon get swapped constantly. Bone to bone, muscle to bone - say it twice.