SPM BIology 2015

Question

7 . Body mass and blood group are two types of variation. Tables 7.1 and 7.2 show the distribution of body mass and blood group from Form 5A students.

Jisin badan dan kumpulan darah adalah dua jenis variasi. Jadual 7.1 dan Jadual 7.2 menunjukkan taburan jisim badan dan kumpulan darah daripada sekumpulan murid Tingkatan 5A.

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

(a) (i) Identify the type of variation in Tables 7.1 and 7.2.

Kenal pasti jenis variasi dalam Jadual 7.1 dan Jadual 7.2.

(ii) Explain the variation in Table 7.1.

Terangkan variasi dalam Jadual 7.1.

(iii) Describe the factors that cause the type of variation in Tables 7.1 and 7.2.

Huraikan factor-faktor yang menyebabkan jenis variasi dalam Jadual 7.1 dan Jadual 7.2.

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

(b) The father’s blood group is AB and the mother’s blood group is O. Explain the possibilities of the offsprings’ blood group by using schematic diagram.

Kumpulan darah bapa ialah AB dan kumpulan darah ibu ialah O. Terangkan kebarangkalian kumpulan darah anak-anak dengan menggunakan gambar rajah skema.

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

New Comer 0

Answers ( 2 )

    0
    2021-02-23T12:55:24+08:00
    This answer is edited.

    7.a)i) Table 7.1: Continuous variation

    Table 7.2: Discontinuous variation

    ii) -For continuous variation, the phenotypic differences form a continuum, there are no distinct differences.

    -There’s a range of intermediate phenotypes between the lowest and largest body mass.

    -This variation is caused by environment effects.

    iii) -Variation can be caused by gene or environment effects or a combination of the two. 

    -Continuous variation is controlled by many genes and it is influenced by a combination of gene and environment effects.

    -Discontinuous variation is controlled by a single gene and it is influenced by gene effects only.

    Genetic variation results from crossing over, independent assortment from meiosis, random fertilisation or mutations.

    Crossing over during prophase I results in the exchange of DNA segments between non-sister chromatids, thus creating new genetic combinations. 

    -During independent assortment, gametes produced may have a variety of genetic combinations. For humans, there is a possibility of 2^23 combinations. 

    Random fertilisation between female and male gametes results in zygotes with different genetic combinations. 

    -There are two types of mutations, chromosomal and gene mutations. These can cause a change in genetic information resulting in new characteristics. 

    -For environment effects, individuals with the same genotype can have different phenotypes.

    -Variation might be caused by environmental factors such as diet, lifestyle, and sunlight.

     

    b)-The blood group is influenced by three alleles, allele A, B and O.

    -The father (blood AB), A and B alleles are codominant.

    -The mother (blood O) is homozygous recessive and has two O alleles.

    -Since O is recessive, the possibilities of offsprings’ blood group are either A or B. And the offspring are heterozygous.

    0
    2021-02-23T12:56:54+08:00

    Schematic diagram for question 7b)


    Attachment

Leave an answer