Chapter 4 – Functioning of organisms: animals including humans
Consider the following statements and click to reveal the answer.
1. How are humans and other animals different from other living organisms?
All means of classifying organisms are fraught with difficulties and there are no easy solutions. In addition to the features mentioned, human and other animal cells have no cellulose cell walls, chloroplasts or large, permanent vacuoles like the cells of plants. Protoctists are usually simple, unicellular organisms. Monerans are also usually simple, unicellular organisms but prokaryotic, which means that their cells have no well-defined nucleus. Fungi are made up of microscopic threads or hyphae rather than true cells. Individual hyphae may contain more than one nucleus.
2. What words do the initial letters of each life process spell out and why are these significant
They spell out Mrs Gren. Mrs Gren is a useful mnemonic or memory aid.
3. What is DNA?
DNA is short for deoxyribonucleic acid. DNA is a large molecule arranged in the shape of a double helix. In the nucleus of a human cell, DNA occurs coiled up in structures called chromosomes. The nuclei of most human cells usually contain 23 pairs of chromosomes.
4. What type of joint are knee and hip joints?
Both are freely movable joints. Knee joints are hinge joints. Hip joints are ball and socket joints.
5. Why do skeletal muscles work in antagonistic pairs?
Skeletal muscles can contract and pull on bones only when stimulated by nerve impulses. There are no corresponding nerve stimuli to relax them.
6. Give three examples of reflex action
Blinking, coughing, sneezing and limb withdrawal are examples of reflex action
7. What is unusual about the pulmonary artery and the pulmonary vein?
Arteries usually carry oxygenated blood. Veins usually carry deoxygenated blood. The pulmonary artery and pulmonary vein do not follow this pattern.
8. Why is it important to clean teeth at least twice per day, using an approved toothpaste and a good brush?
Cleaning teeth in this way helps prevent the build-up of bacteria which feed on food particles and which produce acids which attack the hard enamel and dentine, causing tooth decay. Eventually, bacteria reach the pulp cavity and cause toothache. Cleaning teeth also helps prevent gum disease. The thin film of mucus, saliva, bacteria, food particles and other debris which coats teeth is known as plaque. This can harden to produce tartar or calculus.
9. What is special about the male and female gametes or sex cells?
Male and female gametes or sex cells have only half the number of chromosomes found in other cells. When the nuclei of male and female gametes meet and fuse, the resultant zygote has all of the genetic material it needs to produce a fully grown adult. Humans grow up with the inherited genetic characteristics of both biological parents.
10. Why are antibiotics limited in the treatment of colds and flu?
Colds and flu are caused by viruses. Antibiotics are used to treat bacterial infections.
11. What must you do before bringing any living organisms (other than humans) into a primary classroom?
You should always seek health and safety guidance to ensure that you are not putting yourself and the children in danger from any foreseeable and avoidable risk.
12. Produce sketches of the human skeletal, muscular, circulatory and digestive systems, labelling as many of the different ‘parts’ as you can and annotating them with notes outlining how each system works. Compare your sketches with the illustrations provided in the chapter. How accurate were you about size, shape, location and function?
Sketches, labelling and notes will vary. Check against text and chapter illustrations.
13. List the main vertebrate classes within Phylum Chordata. What are their defining characteristics? List the main invertebrate classes within Phylum Arthropoda. What are their defining characteristics? Produce a formal biological classification scheme that shows the relationship between these groups. Where would you place annelids and molluscs?
The main vertebrate classes within Phylum Chordata include fish, amphibians, reptiles, birds and mammals. The invertebrate classes within Phylum Arthropoda include arachnids, chilopods, diplopods, crustaceans and insects. Check all characteristics and classifications against the text. Annelids and molluscs are separate phyla. They each contain invertebrate organisms commonly examined in primary classrooms.