Explain:
i) population control
ii) advantage of using contraceptive devices
Answers
the restrictions on the increase in population is known as population control.
contraceptive devices either preven the sperms from entering the inner part of vagina..
or prevent the sperm to fertilise the egg...
you always have google for still better answers!!!
Answer:
i) Population control can be influenced by a variety of factors. Humans can greatly influence the size of animal populations they directly interact with. It is for example relatively common (and sometimes even a legal requirement) to spay or neuter dogs. Spaying – removing the ovaries and uterus of a female animal – medical term = ovariohysterectomy. Neutering - removing the testes of a male animal – medical term = orchiectomy. Various humans activities (e.g. hunting, farming, fishing, industrialization, and urbanization) all impact various animal populations.
Population control may involve culling, translocation, or manipulation of the reproductive capability. The growth of a population may be limited by environmental factors such as food supply or predation. The main biotic factors that affect population growth include:
Food – both the quantity and the quality of food are important. Snails, for example, cannot reproduce successfully in an environment low in calcium, no matter how much food there is because they need this mineral for shell growth.
Predators – as a prey population becomes larger, it becomes easier for predators to find prey. If the number of predators suddenly falls, the prey species might increase in number extremely quickly.
Competitors – other organisms may require the same resources from the environment, and so reduce the growth of a population. For example, all plants compete for light. Competition for territory and for mates can drastically reduce the growth of individual organisms.
Parasites – These may cause disease, and slow down the growth and reproductive rate of organisms within a population.
Important Abiotic factors affecting population growth include:
Temperature – Higher temperatures speed up enzyme-catalyzed reactions and increase growth.
Oxygen availability – affects the rate of energy production by respiration.
Light availability – for photosynthesis. light may also control breeding cycles in animals and plants.
Toxins and pollutants – tissue growth can be reduced by the presence of, for example, sulphur dioxide, and reproductive success may be affected by pollutants such as estrogen like substances.
ii) Contraception can be used to plan when women and couples have children and how many children they have. This includes choosing
when they want to begin having children
how far apart they want their children to be
when they want to stop having children.
Contraception lets women and couples have the number of children they want, when they want them. This is everybody’s right under the United Nations Declaration of Human Rights.
Delaying or spacing babies allows women and men to follow education and career goals that may be interrupted by having children. This empowers people and increases their ability to earn more. With fewer children, families are also able to invest more in each child.
REDUCING PREGNANCY-RELATED RISK
Girls and young women are especially at risk of problems in pregnancy. Contraception allows them to put off having children until their bodies are fully able to support a pregnancy. It can also prevent pregnancy for older women who face pregnancy-related risks.
Contraceptive use reduces the need for abortion by preventing unwanted pregnancies. It therefore reduces cases of unsafe abortion, one of the leading causes of maternal death worldwide.
REDUCING TEENAGE PREGNANCIES
Contraceptive use also reduces teenage pregnancies. For a developed country, New Zealand has a very high adolescent fertility rate, at 26 births per 1,000 women aged 15-19 (Australia’s rate is 16 births).
By using contraception, young women can prevent unwanted pregnancies that can have negative impacts on their relationships and ambitions.
Early pregnancy can also cause health problems for the baby. Babies born to teenage women are likely to have be underweight before and at birth and are at higher risk of neonatal mortality (dying within 28 days of birth).
HEALTHY BABIES
Pregnancies that are too close together or poorly timed contribute to high infant mortality rates – that is, the rate of babies that die within their first year of life.
Contraceptive use lets women plan their pregnancies so they can make sure the baby is getting the best care before and after birth.
In the 1950s, before reliable contraception such as the Pill was available, New Zealand had an infant mortality rate of 26.30 infant deaths per 1,000 births.
In 2012 that rate was 4.2, lower than the United States but higher than a number of other developed countries. Better healthcare and hygiene, as well as the use of modern contraceptive methods, have contributed to this great improvement.
POPULATION PRESSURES
Contraceptive use slows population growth. This is important because overpopulation puts pressure on the environment, the economy and services such as education and health.