Variation
Muhtasari
No two individuals of a species are exactly alike, and that variety is the raw material of evolution. Some differences fall into neat, separate categories; others form a smooth range. Understanding which is which, and where new variation comes from, is the bridge between genetics and natural selection.
In this lesson you will define variation, distinguish continuous from discontinuous variation with examples, link each to its causes, investigate both types, and explain mutation as the source of new alleles, including what raises the mutation rate and (for Extended) the other sources of genetic variation in populations.
Malengo
- Describe variation as differences between individuals of the same species
- State that continuous variation results in a range of phenotypes between two extremes; examples include body length and body mass
- State that discontinuous variation results in a limited number of phenotypes with no intermediates; examples include ABO blood groups, seed shape in peas and seed colour in peas
- State that discontinuous variation is usually caused by genes only and continuous variation is caused by both genes and the environment
- Investigate and describe examples of continuous and discontinuous variation
- Describe mutation as genetic change
- State that mutation is the way in which new alleles are formed
- State that ionising radiation and some chemicals increase the rate of mutation
- [Supplement] Describe gene mutation as a random change in the base sequence of DNA
- [Supplement] State that mutation, meiosis, random mating and random fertilisation are sources of genetic variation in populations
Maelezo ya Somo
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Tathmini ya Somo
Hongera kwa kukamilisha somo la Variation. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.
Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.
Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.
- Variation is best defined as: A. differences between individuals of different species B. differences between individuals of the same species C. the inheritance of alleles D. a change in the environment Answer: B
- Which is an example of continuous variation? A. ABO blood group B. tongue rolling C. human height D. seed shape in peas Answer: C
- Discontinuous variation is usually caused by: A. the environment only B. genes only C. genes and the environment D. diet only Answer: B
- Mutation is best described as: A. the shuffling of existing alleles B. genetic change that forms new alleles C. a type of meiosis D. an environmental effect Answer: B
- Which factor increases the rate of mutation? A. a balanced diet B. ionising radiation C. regular exercise D. drinking water Answer: B
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Inapatikana kwenye programu ya Green Bridge
Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.
Vitabu Vinavyopendekezwa
Fanya Mazoezi ya Maswali ya Majaribio
Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Variation? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.
Pakua Programu Kwenye Google Playstore
Kila kitu unachohitaji ili kufaulu katika JAMB, WAEC & NECO.
