science grind

Explain the function of the digestive system.

The digestive system breaks down food into nutrients that the body can absorb for energy, growth, and repair, and removes waste.

: Relate the structure of villi to their function.

Villi are finger-like structures with a large surface area, thin walls, and a rich blood supply, allowing fast absorption of nutrients into the bloodstream.

List key organs and structures of the circulatory system.

Heart, atria, ventricles, blood vessels, arteries, arterioles, capillaries, veins.

Red blood cells

Carry oxygen.

white blood cells

fight infections

Plasma

Carries nutrients, hormones, and waste.

Platelets

Help with blood clotting.

Atria

Receive blood into the heart.

Ventricles

Pump blood out of the heart.

Valves

Prevent backflow of blood.

Muscular walls

Help pump blood with force.

Relate the presence of muscular walls and valves in arteries and veins to the relative blood pressure. Arteries

Thick muscular walls to withstand high pressure.

Relate the presence of muscular walls and valves in arteries and veins to the relative blood pressure Veins:

Thin walls with valves to prevent backflow as pressure is lower.

Define excretion

Removal of metabolic waste from the body.

Amino acids

Building blocks of proteins.

Ammonia

Toxic waste formed from excess amino acids.

Urea

Less toxic waste converted from ammonia in the liver.

Metabolism

All chemical reactions that happen inside the body.

Describe the key organs of the excretory system.

Kidneys, skin, bladder, liver.

kidneys

Filter blood and produce urine.

Liver

Processes toxins and converts ammonia into urea.

Skin:

• Excretes sweat containing water, salt, and small amounts of waste.

Explain the process of excretion of amino acids.

Excess amino acids are broken down into ammonia in the liver, which is converted to urea and excreted by the kidneys.

Relate the structure and function of a nephron.

The nephron filters blood, reabsorbs useful substances, and forms urine for excretion.

Identify the main bones in the skeletal system.

Skull, spine, ribs, pelvis, femur, humerus, tibia, fibula, radius, ulna.

Describe how bones, joints, cartilage and ligaments function together.

• Bones: Provide structure.

• Joints: Allow movement.

• Cartilage: Reduces friction at joints.

• Ligaments: Connect bones and stabilize joints.

Identify different sorts of muscles and how they move.

• Skeletal muscle: Moves bones, voluntary control.

• Smooth muscle: Moves organs, involuntary control.

• Cardiac muscle: Found only in the heart, involuntary.

Describe the main purpose of the skeletal and muscular systems.

To support the body, protect internal organs, allow movement, and produce blood cells.

Define cellular respiration.

A chemical process that releases energy from glucose using oxygen.

Identify the key organs and structures of the respiratory system.

Trachea, bronchi, lungs, pharynx, epiglottis, alveoli, diaphragm.

Describe the role of the respiratory system.

To bring oxygen into the body and remove carbon dioxide waste.

Relate the structure and function of the alveoli.

Alveoli are tiny air sacs with thin walls and a large surface area for efficient gas exchange.

Explain the difference between respiration and breathing.

• Breathing: Moving air in and out of the lungs.

• Respiration: Releasing energy from food inside cells.

Ova

Female egg cells.

Oestrogen

Hormone controlling female development.

Ovulation

Release of an egg from the ovary.

Zygote

Fertilised egg cell.

Foetus:

Developing baby after 8 weeks.

Menstruation

Monthly shedding of uterine lining.

Gestation

Period of development inside the womb.

Describe the female reproductive system.

Vagina, uterus, fallopian tubes, ovaries, endometrium, placenta.

Explain the main processes involved in the menstruation cycle.

Hormonal changes cause the uterine lining to thicken, an egg is released (ovulation), and if unfertilised, the lining sheds (menstruation).

Describe the main structures and functions of the male reproductive system.

Testes (make sperm), penis (deliver sperm), scrotum (hold testes), epididymis (store sperm), vas deferens (carry sperm), seminal vesicles and prostate gland (produce fluid for sperm).

Provide examples of animals that use internal fertilisation.

Humans, birds, reptiles.

Provide examples of animals that use external fertilisation.

Fish, amphibians (frogs).

Explain the difference between internal and external fertilisation.
A:

• Internal: Fertilisation happens inside the body.

• External: Fertilisation happens outside the body.

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Describe the purpose of mitosis and cytokinesis.

• Mitosis: Cell division for growth and repair, making identical cells.

• Cytokinesis: Splitting the cell's cytoplasm into two.

Describe the stages of meiosis I and II.

• Meiosis I: Chromosomes pair up, swap parts (crossing over), separate into two cells.

• Meiosis II: Each cell splits again, making four cells with half the original number of chromosomes.

Explain how four haploid gametes are produced in meiosis.

Two divisions occur, reducing chromosome number by half, resulting in four different sex cells (haploid gametes).

Compare and contrast mitosis and meiosis.

• Mitosis: 2 identical cells, for growth and repair.

• Meiosis: 4 different cells, for reproduction.

Explain that multicellular organisms can survive and reproduce because they contain organ systems with specific functions

Organ systems like digestive, circulatory, and respiratory systems work together to keep organisms alive and able to reproduce.

Identify the importance of washing their hands.

Washing hands removes harmful bacteria and viruses, preventing the spread of disease.

Describe why hygiene is so important.

Good hygiene reduces infections, protects health, and prevents illness from spreading.

Describe the basic tenet of germ theory.

Diseases are caused by microorganisms (germs) that can spread and infect other people.