Chapter 11/12/13

Question 1

Name the components and main function of the Circulatory system.

Answer 1

The three components that the circulatory system is composed of is the heart, the blood and the blood vessels, such as the arteries, veins and capillaries. The main function of the circulatory system is the transport of materials within the internal environment for exchange within all cells.

Question 2

State the three major components of a circulatory system 12.2

Answer 2

1. Blood or a fluid to transport nutrients.
2. Blood vessels.
3. Heart

Question 3

Compare a closed circulatory system with a closed double circulatory system 12.1

Answer 3

In a closed circulatory system, the fluid (blood) flows through enclosed vessels (arteries, veins, capillaries) and is distinct from the interstitial fluid found between cells.

Double circulatory systems (found in everything else) contain two circuits. The pulmonary circuit transports blood ot the lungs and back to the heart, and the systemic circuit transports oxygenated blood around the body and back to the heart.

Question 4

What is the difference between an open and closed circulatory system? 12.1

Answer 4

In an open circulatory system, the fluid (called hemolymph) circulates via the body cavity and bathes the cells; substances enter the cell by diffusion.

In a closed circulatory system, the fluid (blood) flows through enclosed vessels (arteries, veins, capillaries) and is distinct from the interstitial fluid found between cells.

Question 5

List the characteristics of an efficient gas exchange surface. 12.3

Answer 5

• Large Surface area for diffusion
• Highly vascularised
• Concentration gradient.
• Moist for gas to dissolve and diffuse
• Thin and permeable, diffusion path is short

Question 6

Describe the structure of these gas exchange surfaces:

1. Gills
2. Spiracles
3. Lungs
4. 3

Answer 6

1. Long thin filaments increase the area of the surface, which is highly vascularised and uses the countercurrent system. Fish open mouths to allow water to pass over their gills.
2. Spiracles are openings at the body surface that lead to the trachea and are tubes made of chitin that allow oxygen to pass in by diffusion. Trachea branch into tracheoles which carry air directly into the cell for gas exchange.
3. The lungs of mammals take in oxygen by inhalation and the air is warmed and moistened. Oxygen and Carbon dioxide are exchanged with the blood at the surface of the alveoli. air flows into the alveoli sacs then circulates into the alveoli where gas exchange occurs into capillaries by diffusion.

Question 7

Explain how fish can achieve the highest efficiency of gas exchange. 12.3

Answer 7

Fish achieve the highest efficiency of gas exchange due to countercurrent flow. Water flows over the gills in one direction, while blood flows in the opposite direction through gill capillaries. This maximises oxygen transfer because it maintains a concentration gradient along the whole structure.

Question 8

Compare countercurrent flow with cocurrent flow. 12.3

Answer 8

In co-current flow, the concentration gradient between the two areas is reduced the longer they flow together,.

In counter current flow, the concentration gradient is maintained.

Question 9

Describe the main functions of the digestive system. Name the end products. 12.4

Answer 9

The main functions of the digestive system are:

1. Ingestion (eating)
2. Digestion (the breakdown of complex organic molecules into smaller components by mechanical and chemical means.)
3. Absorption (the taking up of digested molecules into the internal environment of the cells of the digestive tract.)
4. Egestion (The removal/elmination of undigested waste food materials from the body)

Question 10

What is the difference between a single and a double circulatory system? 12.1

Answer 10

Single circulatory systems (found in bony fish and sharks) contain one circuit. The heart pumps blood to the gills to be re-oxygenated, then blood flows back to the body and back to the heart.

Double circulatory systems (found in everything else) contain two circuits. The pulmonary circuit transports blood ot the lungs and back to the heart, and the systemic circuit transports oxygenated blood around the body and back to the heart.

Question 11

State the function of the following enzymes:

1. Amylase
2. Pepsin
3. Trypsin
4. Lipase

Answer 11

1. Amylase is secreted by the salivary glands and the pancreas and its function is to break down carbohydrates in to simple sugars.
2. Pepsin is an enzyme secreted in the stomach and is used to break down proteins.
3. Trypsin also breaks down proteins but is used in the small intestine after the proteins had been partially broken down by Pepsin.
4. Lipase is transported into the small intestine and is used to break down triglycerides into fatty acids.

Question 12

What is the alimentary canal? Compare the alimentary canals of herbivores and carnivores.

Answer 12

The alimentary canal is the fancy name for the digestive tract. where the food goes. The alimentary canal for herbivores is different to that of carnivores as herbs have a small stomach as the break down of protein is not necessary herbs will have long intestines as grass and other plant matter is much more difficult to break down and needs more time. the opposite for the carnivores.

Question 13

State the main function of the following vascular tissues:

1. Xylem
2. Phloem

Answer 13

1. Xylen is responsible for the transport of water, along with minerals and other nutrients needed for growth and other processes. Xylem moves from the roots to the leaves.
2. Phloem transports sugars, in the form of sucrose, and other photosynthesis products from one part of a plant (usually the site of creation, the leaves, or the storage place, the roots) to where they are needed are therefore transportation can be in either direction.

Question 14

List the essential requirements for a plant, such as a eucalypt. Name the processes that need these requirements. 13.1

Answer 14

A group of essential requirements is Water, Carbon Dioxide and Sunlight which are required for photosynthesis.

Question 15

Explain why a vascular plant requires a root system and a shoot system. 13.1

Answer 15

All plants need to photosynthesise to survive. The shoot system which sits above the ground enables the plant to access 2 of the 3 requirements for photo. These are carbon dioxide and sunlight. The 3rd, being water is able to be accessed by the root system through the roots taking in water through osmosis.

Question 16

Distinguish between the terms stoma, stomata and guard cells. 13.2

Answer 16

Stoma: Tiny openings in the surface of a plant that gases can enter through or exit through. Found on underside of leaves.

Stomata: A singular stoma.

Guard Cells: Pairs of cells that open and close stomata to control the entry and exit of gases.

Question 17

Name the three gases that are exchanged via stomata 13.2

Answer 17

Carbon dioxide enters

Water vapour and oxygen exit.

Question 18

What are the three gases that move in and out of leaf cells? Identify the use for each. 13.2

Answer 18

Carbon dioxide enters the stomata and water vapour and oxygen exit.

Carbon dioxide is used in the process of photosynthesis in cells with chloroplasts, such as spongy mesophyll cells and palisade cells, found in the leaf of the plant.

Oxygen is a product of photosynthesis as any oxygen produced and not used for respiration exits via the stomata.

Water vapour exits through the stomata from the plants water transport system if it is not used by the plant for metabolic processes such as photosynthesis or respiration

Question 19

Describe the processes that move water into the root hairs. 13.3

Answer 19

Osmosis allows water and minerals to enter the root from the soil in the case of water molecules, and diffusion and active transport in the case of dissolved ions.

Question 20

List the features of the xylem that make it effective in transporting water around the plant. 13.3

Answer 20

1. Xylem is very narrow which, when hollowed, allows the water to climb up the vessels due to adhesion forces.

Question 21

Define and describe translocation.
Suggest where the energy for translocation comes from.
13.3

Answer 21

Translocation is the active movement of soluble sugars (made during photosynthesis) through the Phloem of vascular plants from a source to a sink.

Question 22

Describe the main function of the leaf. 13.3

Answer 22

The main function for the leaf is to act as a site for photosynthesis. This is a site of dense chlorophyll and enables a surface to absorb light energy.

Question 23

List the substances that enter leaves and are used for photosynthesis. 13.3

Answer 23

Substances that enter the leaves and is used for photosynthesis is light energy, diffusing through the epidermis into the chlorophyll and carbon dioxide travelling through the stomata on the underside of the leaf.

Question 24

Define ‘Arid’

Answer 24

Refers to a climate with little to no rain. It is difficult for plants to inhabit arid land.

Question 25

Define ‘adaptation’ and state two types of adaptations demonstrated by desert plants

Answer 25

An adaptation is any change in the characteristics of an organism that makes it better able to survive its environment. Adaptations come in structural (physical) and physiological (process or function). A structural example is altered root systems, location of stomata, and types of tissue.

Question 26

State the difference between a structural adaptation and a physiological adaptation

Answer 26

A structural adaptation is physical where a physiological adaptation is how the plant functions.

Question 27

Describe one structural adaption found in a terrestrial Australian plant.

Answer 27

Kangaroo paws have roots that can bind to sand and have fine root hair that can retain soil moisture around the root and possibly assist in extracting phosphorus from the soil

Question 28

Describe one physiological adaptation found is terrestrial Australian plant.

Answer 28

A physiological adaptation is that Aus plants are able to store light energy collected during the day and then photosynthesise it at night so water is not lost out of the stomate during the day. The stomata closes during the day because it would lose water because of the heat.