Plant Water Absorption and Transport

• Plants absorb water through their roots.
• Soil contains tiny rock particles of different sizes with spaces between them filled with air and water.
• Root hairs, special cells on roots, provide a large surface area for water and mineral ion absorption.
• Water moves into root hair cells from the soil, passing through the cell wall and membrane into the cytoplasm.
• Minerals like magnesium and nitrate, in ion form, also enter root hair cells with water.

Water Transport

• Xylem vessels are the plant's water transport system, located in the center of the root.
• Water moves from root hair cells into the xylem vessels.
• Xylem vessels are long, tube-like, dead cells stacked to form continuous tubes from roots to the plant's highest parts.
• The wood in tree trunks consists of xylem vessels.
• Xylem vessels carry water and mineral ions upwards.

Water Movement in Leaves

• Water moves from xylem vessels into leaf cells.
• Some water is used for photosynthesis.
• Most water evaporates from the cell walls into air spaces then diffuses out through stomata.
• Stomata are tiny holes on the underside of leaves.
• Transpiration is the loss of water vapor from leaves.

Importance of water to plants

• Water helps plants stand upright.
• Plant cells with ample water are firm, supporting the plant's structure.
• Lack of water causes cells to become soft, leading to wilting.
• Water transports dissolved mineral salts from roots to other plant parts.
• Water evaporation cools the plant.
• Water is a key reactant in photosynthesis.

Excretion

• Excretion is the removal of waste materials that have been inside the body.
• Waste from the digestive system (faeces) isn't considered excretion as it has never been inside the body..
• Excretion includes waste substances made in cells and excess substances.
• In animals, excretion includes carbon dioxide from respiration, urea from liver cells, and excess water.
• The liver converts excess protein molecules into urea, which is toxic if it builds up.
• The excretory (renal) system removes urea from the blood.
• Kidneys filter urea and excess water from the blood, creating urine.
• Urine flows through ureters to the bladder, and exits via the urethra.

Pregnancy

• A fetus relies on the mother for nutrients and waste removal.
• The mother's health affects the foetus's health.
• Nutrients diffuse from the mother's blood to the fetus's blood.
• Waste substances diffuse from the fetus's blood to the mother's blood.

Diet During Pregnancy

• A balanced diet is even more crucial during pregnancy.
• Pregnant women need slightly more nutrients to support the growing fetus.
• Protein is essential for fetal cell production and the mother's muscles and haemoglobin.
• Carbohydrates provide energy, but excessive intake can lead to unhealthy weight gain.
• Iron is needed for haemoglobin, and calcium for strong bones in both mother and fetus.
• Vitamins and minerals are very important

Smoking

• Pregnant women who smoke pass carbon monoxide and nicotine to the foetus.
• Carbon monoxide reduces oxygen transport in the blood, affecting fetal development.
• Babies of smoking mothers tend to be smaller.
• Nicotine is addictive and can damage blood vessels.

Drugs

• A drug affects bodily functions.
• Medicinal drugs like antibiotics and painkillers are beneficial in treating diseases and relieving pain.
• Unnecessary drugs, including nicotine, can harm both the pregnant woman and the fetus.
• Most drugs taken by a pregnant woman will reach the fetus through the blood.
• Pregnant women should consult doctors or pharmacists about the safety of prescribed and over-the-counter drugs.