1) Continuous growth refers to a type of growth where there is a gradual and steady increase over time without any distinct stages or interruptions. It can be observed in organisms that continually grow and develop throughout their lifespan, such as humans. Discontinuous growth, on the other hand, refers to a type of growth where there are distinct stages or periods of growth interspersed with periods of little to no growth. This can be observed in organisms that undergo periodic growth spurts, such as insects.
2) Epigeal germination refers to the type of germination in which the cotyledons (embryonic leaves) of a seed emerge above the soil surface. This type of germination is common in dicotyledonous plants. Hypogeal germination, on the other hand, refers to the type of germination in which the cotyledons remain below the soil surface. This type of germination is common in monocotyledonous plants.
3)
a) Hydrophytes are plants that are adapted to live in aquatic environments. Some adaptations of hydrophytes include:
- Reduced or absent waxy cuticle to enhance gas exchange in water
- Floating leaves or air-filled stems for buoyancy
- Reduced root systems or roots specialized for anchoring rather than absorption
- Specialized tissues for storing gases for respiration
- Ability to perform photosynthesis in low light conditions
b) Xerophytes are plants that are adapted to live in arid or dry environments. Some adaptations of xerophytes include:
- Thick waxy cuticle to reduce water loss through evaporation
- Reduced leaf surface area or modified leaves (e.g. needle-like leaves) to minimize transpiration
- Extensive root systems to maximize water absorption
- Ability to enter dormancy during periods of drought
- CAM or C4 photosynthesis to optimize carbon fixation while minimizing water loss.
4)
a) Schistosomiasis (also known as bilharzia):
- Causative agent: Parasitic trematode worms of the genus Schistosoma
- Mode of transmission: Contact with contaminated freshwater bodies, often through swimming or wading
- Life cycle of parasite: Eggs are released in the feces or urine of infected humans and contaminate freshwater bodies where they hatch and infect the intermediate host, snails. The larval form (cercariae) are released from the snails and penetrate the skin of humans, developing into adult worms within blood vessels.
- Effects of the parasite on the host: The adult worms can cause chronic inflammation and damage to various organs, depending on the species. Symptoms can include abdominal pain, diarrhea, blood in urine, and liver damage.
- Adaptive characteristics of the parasite: The parasite has a complex life cycle that involves multiple hosts, which allows it to survive and reproduce in different environments.
b) Ascariasis:
- Causative agent: Parasitic roundworms of the genus Ascaris
- Mode of transmission: Ingestion of food or water contaminated with Ascaris eggs
- Life cycle of parasite: Eggs ingested by humans hatch in the intestines, and the larvae migrate through the bloodstream to the lungs. From the lungs, they are coughed up and swallowed, returning to the intestines to mature into adult worms.
- Effects of the parasite on the host: Heavy infestations can cause abdominal pain, diarrhea, and malnutrition. In severe cases, the worms can cause intestinal blockage or migrate to other organs, potentially leading to more serious complications.
- Adaptive characteristics of the parasite: The parasite produces a large number of eggs that are passed in human feces, increasing the chances of transmission. The eggs are resistant to environmental conditions and can survive for long periods outside the host.
5) The assumptions made when using the capture-recapture method for population estimation are:
a) The population is closed: There should be no immigration, emigration, birth, or death within the population during the study period.
b) Marked individuals are randomly distributed: The marked individuals must mix randomly with the rest of the population and have the same probability of being captured as unmarked individuals.
c) Marks do not affect the success of capture or survival: The marking method should not affect the probability of capturing or recapturing individuals, and marks do not affect the survival or behavior of the individuals.
d) The population has not changed between capture events: The population size remains relatively stable between capture events, and there are no significant changes in the population size due to factors such as births, deaths, immigration, or emigration.
Note: The assumptions may vary depending on the specific application and study design.
1)Differentiate between continuous and discontinuous growth.
2)Describe epigeal and hypogeal Germination.
3)Give 5 adaptations of the following plants to their environment;
a)Hydrophytes
b)Xerophytes
4)Name 2 diseases caused by parasitic worms and for each mention the;
a)Causative agent
b)Mode of transmission
c)life cycle of parasite
d)Effects of the parasite on the host.
e)Adaptive characteristics of the parasite.
5)What are the 4 assumptions made when using captured recapture method for population estimation.
1 answer