Biology - 4BI1 PearsonEdexcel

Transport

Gbogbo ọrọ náà

A single-celled organism can rely on diffusion alone to move substances in and out, but a human body with trillions of cells cannot. Transport systems solve this problem: the circulatory system carries oxygen, nutrients, hormones, and waste products around the body in blood, while in plants the vascular system moves water, minerals, and sugars through xylem and phloem.

In this lesson you will learn the composition of blood, the structure and function of the heart, how arteries, veins, and capillaries differ, how the immune system defends against pathogens, and how transpiration drives the movement of water through a plant. This is one of the largest topics in the specification and appears across both Paper 1 and Paper 2.

Ebumnobi

Understand why simple, unicellular organisms can rely on diffusion for movement of substances in and out of the cell
Understand the need for a transport system in multicellular organisms
Describe the role of phloem in transporting sucrose and amino acids between the leaves and other parts of the plant
Describe the role of xylem in transporting water and mineral ions from the roots to other parts of the plant
Understand how water is absorbed by root hair cells
Understand that transpiration is the evaporation of water from the surface of a plant
Understand how the rate of transpiration is affected by changes in humidity, wind speed, temperature and light intensity
Investigate the role of environmental factors in determining the rate of transpiration from a leafy shoot
Describe the composition of the blood: red blood cells, white blood cells, platelets and plasma
Understand the role of plasma in the transport of carbon dioxide, digested food, urea, hormones and heat energy
Understand how adaptations of red blood cells make them suitable for the transport of oxygen, including shape, the absence of a nucleus and the presence of haemoglobin
Understand how the immune system responds to disease using white blood cells, illustrated by phagocytes ingesting pathogens and lymphocytes releasing antibodies specific to the pathogen
Understand how vaccination results in the manufacture of memory cells, which enable future antibody production to the pathogen to occur sooner, faster and in greater quantity
Understand how platelets are involved in blood clotting, which prevents blood loss and the entry of micro-organisms
Describe the structure of the heart and how it functions
Explain how the heart rate changes during exercise and under the influence of adrenaline
Understand how factors may increase the risk of developing coronary heart disease
Understand how the structure of arteries, veins and capillaries relate to their function
Understand the general structure of the circulation system, including the blood vessels to and from the heart and lungs, liver and kidneys

Akọmọ Ojú-ẹkọ

Your heart beats about 100 000 times every day, pushing roughly 7 000 litres of blood through a network of vessels that, if laid end to end, would wrap around the Earth more than twice. Meanwhile, a tall oak tree lifts hundreds of litres of water from its roots to its canopy every day without a pump. Both systems rely on elegant physical principles, and both are essential for keeping cells supplied with what they need.

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Ayẹwo Ẹkọ

Ekele diri gi maka imecha ihe karịrị na Transport. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.

Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.

Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.

Which blood vessel carries oxygenated blood from the lungs to the heart? A) Pulmonary artery B) Aorta C) Vena cava D) Pulmonary vein Answer: D
What is the function of platelets? A) Carrying oxygen B) Producing antibodies C) Blood clotting at wound sites D) Transporting hormones Answer: C
Which plant tissue transports dissolved sugars? A) Xylem B) Phloem C) Epidermis D) Palisade mesophyll Answer: B
Which factor would DECREASE the rate of transpiration? A) Higher temperature B) Higher wind speed C) Higher humidity D) Higher light intensity Answer: C
Why is the left ventricle wall thicker than the right? A) It receives more blood B) It needs to generate higher pressure for the systemic circulation C) It pumps blood to the lungs D) It contains more valves Answer: B