1a. General: Explain in simple terms why food is required by animals. The main types of food are carbohydrates, fats and proteins. Carbohydrates and fats are required as sources of energy. Proteins are required for growth and repair of damaged or worn out tissues. 1b. Credit: State the chemical elements present in carbohydrates, proteins and fats. See table below 1c. Credit: Describe the simple structure of carbohydrates, fats and proteins in terms of simple sugars, amino acids, fatty acids and glycerol. See table below Food Group Carbohydrates Fats Proteins Elements present Carbon (C) Hydrogen (H) Oxygen (O) Carbon (C) Hydrogen (H) Oxygen (O) Basic units Glucose molecules Fatty acids and glycerol Structure Glucose molecules G L Y C E R O L Fatty acids Carbon (C) Hydrogen (H) Oxygen (O) Nitrogen (N) Amino acids Amino acids Animal survival summary booklet page 1
2a. General: State that digestion is the breakdown of large particles to allow absorption into the bloodstream through the small intestine wall. Digestion = breakdown of large food particles into smaller food particles that can be absorbed through the wall of the small intestine into the bloodstream. 2b. Credit: Explain that digestion involves the breakdown of insoluble food substances into soluble food substances. Starch molecule (insoluble) Glucose molecules (soluble) 3. General: Describe the role of different types of teeth in the mechanical breakdown of food in the mammals chosen. Different mammals eat different foods: - Humans are omnivores and eat plant and animal materials - Sheep are herbivores and eat plant material - Dogs are carnivores and eat animal material There are four types of teeth: i. incisors ii. canines iii. premolars iv. molars In humans: - the incisors are chisel-shaped for cutting and biting - the canines are pointed for gripping - the premolars and molars have blunt points and depressions for cutting Animal survival summary booklet page 2
In sheep: - on the upper jaw instead of incisors and canines there is a horny pad - the lower canines look like incisors - the incisors and canines are forward pointing and have sharp edges for chopping off grass against the horny pad - the premolars and molars are ridged for grinding the grass In dogs: - the incisors are short and pointed to grip and pull flesh off the bone - the canines are long and pointed for piercing and holding their prey - the premolars and molars have sharp cutting edges for slicing flesh and cracking bones 4a. General: Identify in a diagram or model the main parts of the mammalian alimentary canal and associated organs. salivary gland liver oesophagus Gall bladder pancreas appendix stomach small intestine large intestine rectum anus Animal survival summary booklet page 3
4b. Credit: State the sites of production of the main digestive juices in a mammal. The sites of production of the main digestive juices are: - salivary glands - stomach - liver - pancreas - small intestine wall 4c. Credit: Explain the mechanism of peristalsis. During peristalsis the muscular gut wall pushes food along the gut. Muscles in the wall of the gut contract behind and relax in front of the food so pushing the food along the gut. 4d. Credit: Explain how the contractions of the stomach help in the chemical breakdown of food. Contractions of the muscles in the stomach wall help to mix the food with digestive juices which speed up the breakdown of food. 5a. General: State the different enzymes are responsible for the breakdown of carbohydrates, proteins and fats. Digestive enzymes are chemicals which speed up the breakdown of food. Carbohydrates, proteins and fats are broken down by different enzymes. 5b. Credit: Give an example of an amylase, a protease and a lipase. State their substrates and products. Substrate Enzyme Product starch salivary amylase maltose pancreatic amylase protein pepsin (in gastric juice) trypsin (in pancreatic juice) peptides and amino acids fat pancreatic lipase fatty acids and glycerol Animal survival summary booklet page 4
6a. General: Explain how the structure of the small intestine is related to its function. The small intestine is adapted to carry out its function of absorption in that: i. it is long and has a folded lining to create a large surface area ii. the surface area is greatly increased by many finger-like projections iii. the lining is very thin to allow food substances to pass through more easily iv. it possesses a blood supply 6b. Credit: Explain how the structures of the villus, including the lacteal and blood capillaries, are related to the absorption and transport of food. Villi are adapted for the absorption and transport of food in that: i. they contain a dense network of blood blood capillary capillaries into which the glucose and amino acids are absorbed for transport lacteal to other parts of the body. ii. cells in the lining combine fatty acids and glycerol to form fats. iii. the fats are passed into branches of the lymphatic system called lacteals iv. the lymphatic system passes the fats to the blood system for distribution round the body 7. General: Describe the role of the large intestine in water absorption and elimination. The wall of the large intestine absorbs most of the water from the undigested food. The undigested remains (faeces) are eliminated through the anus. Animal survival summary booklet page 5
8. General: Describe the main features of sperm and eggs. A sperm is the male sex cell head A sperm consists of a head, nucleus and tail A sperm can swim A sperm is smaller that an egg tail nucleus An egg is the female sex cell An egg contains the female nucleus cytoplasm with An egg contains a food store food store 9a. General: State that in some fish, sperm are deposited in water adjacent to the eggs and that in mammals, sperm are deposited in the body of the female. Trout produce many sex cells Trout release sex cells into the water Courtship rituals in trout ensure adjacency of sex cells In trout fertilisation is external In mammals fertilisation is internal 9b. General: Describe the process of fertilisation. Fertilisation involves the fusion of the nuclei of one sperm and one egg. Following fertilisation, a fertilisation membrane forms preventing other sperm entering. 9c. Credit: Explain the importance of internal fertilisation to landliving animals. In the absence of water internal fertilisation is the appropriate mechanism. Internal fertilisation results in the sex cells being closer together. Internal fertilisation does not require as many sex cells to be produced as less are destroyed. Chances of fertilisation are greater in internal fertilisation. Internal fertilisation is more efficient. Animal survival summary booklet page 6
10a. General: State that sperm cells are produced in the testes. sperm duct urethra penis testis site of sperm production 10b. General: State that eggs are produced in ovaries and are released into oviducts where fertilisation takes place. Eggs are produced in the ovaries, then are released into the oviducts. The oviducts are the site of fertilisation. The fertilised egg develops into an embryo. oviduct site of fertilisation ovary produces eggs uterus vagina 11a. General: State that in fish, eggs are protected by flexible coverings and that the embryos obtain food from enclosed yolk. A fish egg consists of an embryo, soft shell and food supply called yolk. The fish embryo feeds from the yolk. 11b. General: Describe how the fertilised egg passes down the oviduct and becomes attached to the wall of the uterus, develops in fluid of the amniotic sac and obtains food from the maternal circulation. The fertilised mammalian egg moves down the oviduct. Animal survival summary booklet page 7
The egg attaches itself to the spongy uterus wall = implantation. The embryo develops in fluid of the amniotic sac. The embryo obtains food from circulation of the mother. The mother s and embryo s circulations are separate but in close contact for exchange of materials. 11c. Credit: Explain the relationship between the number of eggs/young produced and the degree of protection afforded during fertilisation and development in fish and mammals. As the chance of fertilisation increases the number of eggs produced decreases. In order to increase the probability of successful development with little or no parental care, as is the case in most fish, the number of eggs produced increases. 11d. Credit: Describe the structure and function of the placenta. An embryo mammal develops a placenta. The embryo is attached to the placenta via the umbilical cord. The placenta allows exchange of food and oxygen from mother s circulation. The placenta allows exchange of waste and carbon dioxide from the embryo s circulation. Harmful substances e.g. drugs may pass to the embryo through the placenta. 12a. General: State that in a fish, like the trout, the young emerge from the eggs able to maintain themselves. The newly hatched trout has a yolk sac for nourishment. The newly hatched trout receives no parental care and maintains itself. After absorption of the yolk sac the young trout can feed itself. 12b. General: State that at birth, the young of mammals are dependent on the adult for care and protection. The embryo mammal leaves the uterus at birth. The young mammal suckles milk from the mother. Animal survival summary booklet page 8
13a. General: Identify the ways in which a mammal gains and loses water. A mammal gains water from: i. drink ii. food iii. respiration A mammal loses water in: i. sweat ii. breath iii. urine iv. faeces 14a. General: State that the kidneys are the main organs for regulating the water content in a mammal. In a mammal water gain equals water loss. The kidneys are the main organs for regulating the water content in a mammal. Kidneys adjust the water content by regulating the volume and concentration of urine. 14b. Credit: Explain the role of ADH in the regulation of water balance. The brain detects changes in the water content of the blood. The hormone ADH (Anti-Diuretic Hormone) controls kidney function. high water intake blood water content = normal too much salt / sweating brain produces less ADH brain produces more ADH low water reabsorption by kidney blood water content = normal high water reabsorption by kidney Animal survival summary booklet page 9
15a. General: Identify the positions and state the function of the kidney, renal arteries and veins, ureter and bladder. renal artery renal vein kidney ureter to bladder Structure kidney Function Excretes urine and maintains water balance in the body by regulating the water content of the body Renal artery Blood vessel that carries unpurified blood to the kidney Renal vein Blood vessel that carries purified blood away from the kidney Ureter Tube that passes urine from the bladder to the external environment Bladder Stores the urine before it is passed out of the body 15b. General: State that essential kidney functions are filtration of blood and reabsorption of useful materials such as glucose. The essential elements of kidney function are filtration and reabsorption. 15c. General: State that urea is a waste product removed in the urine. In the kidney both poisonous and useful substances are filtered from the blood. The waste substance urea is passed out in the urine. Animal survival summary booklet page 10
Glucose and water are useful substances that are reabsorbed in the kidney. 15d. Credit: Explain the process of urine production using a simple diagram of the nephron, to include the Bowman s capsule, glomerulus, blood capillaries and collecting duct. Blood enters the nephron via a branch of the renal artery glomerulus The renal artery divides into a group of capillaries called the glomerulus, which is surrounded by the Bowman s capsule Blood is filtered through the glomerulus and the filtrate collects in the Bowman s capsule The glomerular filtrate then passes into the kidney tubule where useful substances capillary such as glucose, vitamins, salts and water are reabsorbed back into the blood in surrounding capillaries Bowman s capsule The remaining liquid contains the waste products such as urea and some water continues along the tubule to the collecting duct, where it is then passes into the ureter, into the bladder until it is ready to leave the water. 15e. Credit: State the source of urea in the body and describe how urea is transported to the kidneys. Urea is a waste produced in the liver by the breakdown of amino acids in the liver. Urea is carried from the liver to the kidneys by blood vessels. 16a. General: Explain the implications of damage to the kidneys by accidents or disease. Kidney damage through accidents or disease can lead to a build up of poisonous wastes in the body. 16b. Credit: Describe the relative benefits and limitations of replacement and artificial kidneys. Total kidney failure is fatal if not treated Patients with failed kidneys can be treated by: - dialysis on a kidney machine (artificial kidney) - a kidney transplant The inconvenience associated with kidney machines are that: collecting duct Animal survival summary booklet page 11
- they are expensive - dialysis takes several hours per week and so life is restricted - patients may suffer other related medical problems and so must follow a careful diet The benefits to the patients of the kidney transplant are: - it saves the patient s life - the patient may resume a normal life The inconvenience associated with kidney transplants are that: - there are a shortage of donors - there is a possibility of rejection of the kidney Animal survival summary booklet page 12
17a. General: Give examples of environmental factors which affect behaviour. Light, chemicals and humidity are three environmental factors which affect behaviour. 17b. General: Describe the response of an animal to change in one environmental factor. Describe the response of an animal to change in one environmental factor e.g. maggots to light, woodlice to light or humidity, planarian to chemical etc. 17c. Credit: Explain the significance of given examples of response to environmental stimuli in the life of the organism concerned. Responses to environmental stimuli are important for an animal s survival. Woodlice move towards the stimulus moisture, which keeps the breathing system moist allowing the woodlouse to breathe. Blowfly maggots move away from the stimulus light, which ensures that they stay in dark places to obtain food and protection. 18a. General: Describe examples of rhythmical behaviour and in each case identify the external trigger stimulus. Rhythmical behaviour in animals results from regular events in the environment. Migration is an annual rhythm which is triggered by changes in day length. Activity in shore crabs is a tidal rhythm which is triggered by the movements of the tide. 18b. Credit: Explain the significance of given examples of rhythmical behaviour in the life of the organism concerned. Rhythmical behaviour is an adaptation in animals behaviour which allows it to exploit regular events in the environment. Animal survival summary booklet page 13
Rhythmical behaviour increases an animal s chance of survival e.g. by hibernating, a squirrel is able to conserve energy whilst food is in short supply. Animal survival summary booklet page 14