Monohybrid Inheritance
Gbogbo ọrọ náà
Why does a calf from two hornless parents sometimes grow horns? Why can two ordinary-looking cereal plants give some drought-tolerant offspring and some that wilt in the first dry spell? The answer lies in genes, the units of inheritance passed from parent to offspring. When a single gene controls one feature, we can actually predict the offspring and the ratios in which they appear, which is exactly what a farmer who is planning a breeding programme needs to know.
In this lesson you will learn the language of inheritance: chromosomes, genes and alleles, and what it means for an allele to be dominant or recessive. You will draw genetic diagrams, or Punnett squares, to predict the results of simple crosses and work out the 1:1 and 3:1 ratios that examiners ask about. Finally you will see why the difference between an animal's genotype and its phenotype matters so much when choosing which animals and plants to breed from.
Ebumnobi
- (a) define the terms chromosome, gene, allele, homozygous, heterozygous, dominant and recessive.
- (b) calculate and predict the results of simple genetic crosses involving 1:1 and 3:1 ratios.
- (c) explain the meaning of the terms genotype and phenotype and assess their importance in animal and plant breeding.
Akọmọ Ojú-ẹkọ
Ọ dị na ngwa Green Bridge
Budata ngwa Green Bridge CBT na ekwentị maọbụ kọmputa gị iji nweta akwụkwọ ndụmọdụ zuru oke, ajụjụ mmụta, na ndị ọzọ.
Ayẹwo Ẹkọ
Ekele diri gi maka imecha ihe karịrị na Monohybrid Inheritance. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- Which term describes an organism that has two different alleles of a gene, such as Hh? A. Homozygous B. Heterozygous C. Dominant D. Recessive Answer: B
- The allele for no horns, H, is dominant over the allele for horns, h. What is the phenotype of an animal with the genotype Hh? A. Horns B. No horns C. Half-formed horns D. It cannot be predicted Answer: B
- Two heterozygous cattle (Hh) are crossed. What is the expected ratio of offspring with no horns to those with horns? A. 1:1 B. 1:2 C. 3:1 D. 1:0 Answer: C
- Which genotype is homozygous recessive? A. HH B. Hh C. hH D. hh Answer: D
- A drought-resistant cereal (D dominant) is crossed Dd x dd. What proportion of the offspring is expected to be drought resistant? A. None B. One quarter C. One half D. All Answer: C
Ọ dị na ngwa Green Bridge
Budata ngwa Green Bridge CBT na ekwentị maọbụ kọmputa gị iji nweta akwụkwọ ndụmọdụ zuru oke, ajụjụ mmụta, na ndị ọzọ.
Ọ dị na ngwa Green Bridge
Budata ngwa Green Bridge CBT na ekwentị maọbụ kọmputa gị iji nweta akwụkwọ ndụmọdụ zuru oke, ajụjụ mmụta, na ndị ọzọ.
Àwọn Ìwé Tó Dáa Láti Kà
Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara Monohybrid Inheritance? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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