Showing posts with label exam. Show all posts
Showing posts with label exam. Show all posts

Tuesday, 2 May 2017

Stem-Borrowing Pest

Classification

  • These live within the plants stem, often found stunting growth or killing the apical meristem.
  • May also infect the roots and leaves
  • May be a disease vector

Nematodes

  • Stem Nematodes include Ditylenchus and Aphelencoides spp.

Diagram of Ditylenchus Dipsaci


  • plant pathogenic nematode that primarily infects onion and garlic. It is commonly known as the stem nematode, the stem and bulb eelworm or onion bloat.
  • Live in the roots of the plants to infect their host.
  • Symptoms of infection include stunted growth, discoloration of bulbs, and swollen stems.

Coleoptera

Cabbage Stem- Weevil
 
  • There's species are more often seen from spring to autumn
  • The larvae develops in the stems of the brassicas and then continues its feed from there.
  • Widespread throughout England and Wales
  • Control used to reduce the amount is by seed treatments of gamma-HCH or Sprays of gamma-HCH, Azinphos-Methyl, Azinphos-methyl + demeton-s-methyl sulphone, chlorpyrifos or triazophos. (GRAHAM and GOULD, 1980)

Diptera

Frit Fly Life Cycle Showing that it is constantly living throughout the seasons

 
  • The Frit Fly usually white, yellow and black and are often found in grassy areas.
  • They cause damage to new turf by destroying the stems of ryegrass, fescues and bents (use of larvae)
  • Adult Flies are attracted to white objects and if a sighting of a large number of these flies could indicate larvae
  • Larvae dig tunnels, infect stems and stay through winter
  • Fruit Flies can be controlled by chemical sprays

Lepidoptera

Rose Stem Girdler (Species Unknown)

 
  • Metallic wood boring beetle
  • Flathead larvae is the known youngling of the group they cause the most damage to the rose by borer tunnelling within the pithy centre of the stem.
  • Swollen, gall-like area on canes
  • Canes with wilted, dried leaves
  • Upper portions of canes break off easily during the summer
  • Tunnelling in the lower part of the cane
  • Boring damage and galleries inside of the cane
  • CONTROL; insecticides to kill any larvae and eggs, remove infected plants over the season and over winter  

references;

GRAHAM, C. and GOULD, A. (1980). Cabbage stem weevil (Ceutorhynchus quadridens) on spring oilseed rape in Southern England and its control. Annals of Applied Biology, 95(1), pp.1-10.

Friday, 28 April 2017

Soil/Root Dwelling - Homoptera

Cabbage Root Maggots

Cabbage root maggot flies are delicate, hump backed grey-brown flies, about 5-7mm long. Cabbage maggot flies are difficult to distinguish with the naked eye, but each will only be found on their appropriate family crop.
Cabbage Root maggot infesting a cabbage under a microscope.



  • Small, white bullet shaped eggs are laid in the soil to form maggots which are white and legless they are found in the roots and around the roots as well.
This image shows how cabbage root has affected roots to the crops hugely and reduced the roots making it unable for growth. On top of this, the plant is parasitic for human consumption.




Onion and seedcorn maggot flies are very similar! 


Wednesday, 15 March 2017

Past Paper example

DESCRIBE THE MAIN BEHAVIOURAL ADAPTATIONS FOR CONSEVING HEAT IN MAMMALS.
Adaptations help organisms survive in their habitats or ecological Niche, adaptations can be behavioural or physiological.
 Behavioural adaptations can be inherited or learnt and include tool use, language and swarming behaviour. for example Heat tolerant animals and adaptations for survival in hot places. Many animals try to avoid the heat by hiding away during the hottest parts of the day in burrows and dens. Others have physical adaptations that help body heat dissipate, such as large ears. To avoid being scorched.
but animals that are Cold tolerant  have evolved various methods for coping with very low temperatures. Some animals hibernate, take shelter, or even migrate to warmer areas. Others, such as Antarctic seals, have warm fur and a thick layer of blubber for insulation. where as Arctic foxes have short noses, legs, and ears. But has a big furry tail to wrap around them to isolate them during the icy storms at night. They only hunt during they day to avoid the harsh winter night
      • HOW MIGHT A MARINE MAMMAL BALANCE IT'S CELLULAR OSMOLARITY WITH IT'S ENVIRONMENT?
      Marine Animals are osmoconformers their body fluids are similar to seawater in osmolalrity, so they gain and lose water at equal rates and have no need to expend energy expelling water or salt from the body. However, if they are placed in water more or less concentrated than seawater, their tissues shrink or swell, their organelles and cell membranes are damaged, and they die

      DESCRIBE THE RESPIRATORY PATHWAYS WHICH MIGHT BE EMPOLYED DURING THE FIRST FIVE MINUTES OF MODERATE EXERCISE CARRIED OUT BY AN ATHLETE?

       Nutrients are built upon an understanding of how nutrients such as carbohydrate, fat, and protein contribute to the fuel supply needed by the body to perform exercise. These nutrients get converted to energy in the form of Adenosine Triphosphate or ATP.

      It is from the energy released by the breakdown of ATP that allows muscle cells to contract. However, each nutrient has unique properties that determine how it gets converted to ATP. for example carbohydrates is the main nutrient that fuels exercise of a moderate to high intensity, while fat can fuel low intensity exercise for long periods of time. Proteins are generally used to maintain and repair body tissues, - not normally a power source


      • WHAT ARE THE RELATIVE COSTS AND BENEFITS OF ENDOTHERMY?
      An endotherm is an organism which maintains its body at a metabolically favourable temperature, largely by the use of heat set free by its internal bodily functions instead of relying almost purely on ambient heat.
      therefore....
      1. Endothermic animals can inhabit areas that are too cold for ectothermic animals. They also have the ability to be active even when it is cold. 

       2. Ectothermic animals need far less food. As much as 80% of the food energy acquired by an endothermic animal is used just to keep warm

      • HOW DO ENVIRONMENTAL TEMPERATURE CHANGES AFFECT CELLULAR RESPIRATION IN AN ECTOTHERM?
      An Ectotherm are so called cold blooded animals that rely on external sources such as sunlight or rock faces to heat up there internal bodies. Therefore Environmental temperature is vital to Ectotherms,  if the environment temperature lowers cellular respiration could be affected due to the enzyme structures within the body being affected meaning growth, breathing, sexual interaction, are all depleting slowly.

      • HOW MIGHT AN ECTOTHERM RESPOND TO THESE CHANGES?
      Ectotherms will respond quickly to these changes and find shade to equal there temperature to what it should be or if it needs to be higher they will find sun and bask in it to increase the temperature.

      • WHAT ARE THE MAIN FACTORS AFFECTING THE EFFICIENCY OF GAS DIFFUSION FROM THE LUNG TO THE TISSUES OF AN ANIMAL?
      Temperature (Viscosity of medium)
      Area over which exchange occur
      Concentration gradient
      Distance over which Substance diffuse









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