Back to Course

JUPEB: BIOLOGY

0% Complete
0/0 Steps

Quizzes




  • Kofa Study
Quiz 15 of 15

JUPEB 2019 BIOLOGY: Essay Questions

JUPEB: BIOLOGY JUPEB 2019 BIOLOGY: Essay Questions

Responses

Your email address will not be published. Required fields are marked *

(a) Genotype of parents is “Aa”; genotype of albino children is “aa”

(b) The condition of one (1) of the albinos is called Oculocutaneous albinism.   It is inherited in an autosomal recessive pattern, which means both copies of a gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene^ but they do not show signs and symptoms of the condition.

XCXC        XCXC           XCY       XCY

XCXC (female with normal vision)

XCXC (carrier female)

XCY (male with normal vision)

XCY (colour blind male)

(d) Genotype of the man is XCY; genotype of the wife is XCX°

(a) Population size is simply the number of individuals in the population, while population density, the number of individuals per area or volume of habitat. A variety of methods can be used to sample populations to determine their size and density. Two of the most important methods are the quadrat and mark-recapture methods. Quadrat method

For immobile organisms such as plants—or for very small and slow-moving organisms—plots called quadrats may be used to determine population size and density. Each quadrat marks off an area of the same size—typically, a square area—within the habitat. A quadrat can be made by staking out an area with sticks and string or by using a wood, plastic, or metal square placed on the ground. After setting up quadrats, researchers count the number of individuals within the boundaries of each one. Multiple quadrat samples are perfonned throughout the habitat at several random locations, which ensures that the numbers recorded are representative for the habitat overall. In the end, the data can be used to estimate the population size and population density within the entire habitat. Mark-recapture method

For organisms that move around, such as mammals, birds, or fish, a technique called the mark-recapture method is often used to determine population size. This method involves capturing a sample of animals and marking than in some way—for instance, using tags, bands, paint, or other body markings, as shown below. Then, the marked animals are released back into the environment and allowed to mix with the rest of the population.

Using this information, we can formulate the following relationship:

number marked first catch (M) = number marked second

catch (x)

total population (N) total number of second catch (n)

M/N=x/n

Next, we rearrange the equation:

N=nM/x

(b)

i. rope (for quadrant)

ii.   stick   (for   quadrant)

iii. marker

iv. net (to capture organisms)

(c) Population Density = Number of People/Land Area = 700/100 = 7

(a) i. Biological Control:

  1. Biological control or biocontrol is a method of controlling pests such as insects, mites, weeds and plant diseases using other organisms.
  2. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role.
  3. It can be an important component of integrated pest management (IPM) programs.
  4. Classical (importation), where a natural enemy of a pest is introduced in the hope of achieving control.
  5. Inductive (augmentation), in which a large population of natural enemies are administered for quick pest control.
  6. Inoculative (conservation), in which measures are taken to maintain natural enemies through regular reestablishment.

 ii. Chemical control:

  1. Chemical pesticides are often used to control diseases, pests or weeds.
  2. Chemical control is based on substances that are toxic (poisonous) to the pests involved.
  3. Chemical pesticides are often not just toxic to the organisms for which they were intended, but also to other organisms.
  4. Organisms can become immune to a substance, so they no longer have an effect. –
  5. If sprayed plants are eaten by an organism, and that organism is then eaten by another, the chemicals are can be passed up the food chain.
  6. The remains of pesticides may soak into the soil or groundwater and the contaminated water might then be used to spray the crops or be drunk by animals.

(b)

i. Climate change will stunt plant growth,

ii. Declining plant growth would destroy forests and dramatically change the habitats that are necessary for many species to survive.

iii. Future climate change will likely negatively affect crop production in low latitude countries, while effects in northern latitudes may be positive or negative.

iv. Climate change will affect plant biodiversity.

(a)

  1. Ferns are seedless vascular plants of humid tropics and temperate areas.
  2. Plant body is a sporophyte. It is differentiated into true stem, leaves and roots.
  3. The stem is an underground rhizome in most of the ferns.
  4. Roots are adventitious.
  5. Leaves are large and are called fronds.
  6. Leaves possess apical meristem or growing point which, however, stops activity after reaching maturity.
  7. Younger parts of the stem, young leaves, petiole, and rachis of mature leave possess hairs or scales called ramenta. Rarnenta protects them. from mechanical injury and
  8. Sporangia occur on the leaves in clusters called sori (singular-sorus). The fertile leaves are known as sporophylls. A sorus is covered by a flap-like outgrowth from its surface (true indusium e.g Dryopteris ) or turned margin of the sporophyll (false indusium e.g Adiantum)
  9. Vegetative reproduction occurs by fragmentation of rhizome, adventitious buds (e.g, Dryopteris), bulbils, etc
  10. The gametophyte is thalloid and called pro-thallus Pro-thallus is the term used for free-living gametophyte having sex organs. It develops a young sporophytic plant body from inside the female sex organ.
  11. Male sex organs or antheridia are small hemispherical structures with generally a 3- celled jacket enclosing 32—48 sperm mother cells
  12. Female sex organs or archegonia are flask-shaped structures that are partially embedded in the pro-thallus. The tubular neck of the archegonium has 4-rows of cells
  13. Sperms are generally multi-ciliate or multi-flagellate.
  14. An embryo stage is present.
  15. The life cycle has a regular alternation of a dominant sporophyte and an inconspicuous gametophyte. This is called heterologous or heteromorphic alternation of generations.

b

(a)

i. Mesopliiles: are organisms that grow best in moderate temperature, neither too hot nor too cold, typically between 20 and 45 °C (<?8 and 113 °F).

ii. Halophiles: are organisms that thrive in high salt concentrations.

iii. Acidophiles: are organisms that thrive under highly acidic conditions (usually at pH 2.0 or below).

iv. Alkaliphiles: are capable of survival in alkaline (pH roughly 8.5-11) environments, growing optimally around a pH of 10.

v. Thermophiles: are an organism that thrives at relatively high temperatures, between 41 and 122 °C (106 and 252 °F).

(b)

i. Microorganisms in food

Microorganisms are used in the production of fermented food and beverages. E.g. Yeast, Penicillium, Lactobacillus.

ii. Microorganisms in Medicine

They also have immense potential in the field of medicine. They are used industrially for the production of antibiotics, vaccines. Insulin, growth hormones and diagnostic kits. E.g. is. coli, Poliovirus.

iii. Microorganisms in Industry

Industrially important acids, enzymes, pigments are produced with the help of microorganisms. E.g. Aspergillus niger, Bacillussubtilis.

iv. Microorganisms in Agriculture

Microorganisms have been ruling in agriculture from the past century. They are used as Biofertilizers and Biopesticides. E.g. Rhizobium, Bacillus, Azotobacter.

v. Microorganisms in Environment

Ability of microorganisms to degrade toxic materials like oil, petroleum, plastic, etc has opened a new field of research. E.g. Pseudomonas, Alcanivorax.

(a) Culture media

Culture media contain all the elements that most bacteria need for growth and are not selective, so they are used for general cultivation and maintenance of bacteria kept in laboratory culture collections.

Minimal media

A defined medium that has just enough ingredients to support growth is called a Minimal Medium. The number of ingredients that must be added to a minimal medium varies enormously depending on which microorganism is being grown.

(b) Some prokaryotic species have an outer capsule outside the cell wall, which enables the organism to attach to surfaces, protects it from dehydration and attack by phagocytic cells, and makes pathogens more resistant to our immune responses. Some species also have flagella (singular, flagellum) used for locomotion, and pili (singular, pilus) used for attachment to surfaces.

(c)

The bacterial growth curve represents the number of live cells in a bacterial population over a period of time. There are four distinct phases of the growth curve: lag, exponential (log), stationary, and death. The initial phase is the lag phase where bacteria are metabolically active but not dividing. The exponential or log phase is a time of exponential growth In the stationary phase, growth reaches a plateau as the number of dying cells equals the number of dividing cells.

The death phase is characterized by an exponential decrease in the number of living cells.

Phases of the Bacterial Growth Cycle

(a)

b

i. Four species of Plasmodium have long been known to cause malaria in humans: Plasmodium falciparum, P. vivax, P. ovale, and P. malariae.

ii. Malaria causes death in hundreds of thousands per year.

iii. Malaria can reduce school and work attendance.

iv. Malaria epidemic could affect productive population.

(a)

i. These are creeping and burrowing terrestrial animals with scales on their body.

ii. They are poikilothermic animals found in most of the warmer regions of the world.

iii. Their skin is dry, and rough, without any glands.

iv. The body is divided into head, neck, trunk, and tail.

v. Few of these shed the scales on their skin as skin cast.

vi. The respiration takes place with the help of the lungs.

vii. The skull is monocondylic.

viii. They have two pairs of pentadactyl limbs, each bearing claws. Snakes are an exception.

ix. The heart is 3 chambered. However, crocodiles have a 4-chambered heart.

x. The nervous system comprises of 12 pairs of cranial nerves.

(b)

i. In order to live on land, amphibians replaced gills with another respiratory organ, the lungs.

ii. Skin that prevents loss of water.

iii. Eyelids that allow them to adapt to vision outside of the water.

iv. An eardrum developed to separate the external ear from the middle ear.

v. A tail that disappears in adulthood (in frogs and toads).

 

 

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .
error: Alert: Content selection is disabled!!