inheritance Flashcards
Asexual reproduction involves only mitosis. Give one reason why offspring produced by
asexual reproduction may vary in
(i) genotype;
(ii) phenotype but not in genotype.
Asexual reproduction involves only mitosis. Give one reason why offspring produced by
asexual reproduction may vary in
(i) genotype;
mutation
(ii) phenotype but not in genotype.
environmental factors;
The formation of gametes during sexual reproduction involves meiosis. Give two ways in
which meiosis results in genetic variation in the gametes produced.
The formation of gametes during sexual reproduction involves meiosis. Give two ways in
which meiosis results in genetic variation in the gametes produced.
crossing over;
random assortment of chromosomes;
crossing over
sharing of genetic material between two non sister chromatids
Explain why the sperms produced by a man are genetically different from each other.
Explain why the sperms produced by a man are genetically different from each other.
produced by meiosis;
crossing over;
independent assortment of chromosomes;
In honeybees the sex of the offspring is determined by the female parent, the queen. The
queen honeybee mates early in her lifetime, and stores the sperm in her body for use
during the rest of her life. She produces a female by fertilising an ovum as it passes the
store of sperms. She produces a male by allowing an ovum to pass the store without
releasing sperms onto it.
(i) Using this information, complete the table below to show which of the cells are
haploid and which are diploid.
Female honeybee body cell Diploid
Male honeybee body cell _____
Honeybee ovum _____
Honeybee sperm _____
Explain why the sperms produced by a male honeybee are genetically identical to
each other
In honeybees the sex of the offspring is determined by the female parent, the queen. The
queen honeybee mates early in her lifetime, and stores the sperm in her body for use
during the rest of her life. She produces a female by fertilising an ovum as it passes the
store of sperms. She produces a male by allowing an ovum to pass the store without
releasing sperms onto it.
(i) Using this information, complete the table below to show which of the cells are
haploid and which are diploid.
Female honeybee body cell Diploid
Male honeybee body cell haploid
Honeybee ovum haploid
Honeybee sperm haploid
Explain why the sperms produced by a male honeybee are genetically identical to
each other
produced by mitosis;
Explain why the sperms produced by a male honeybee are genetically identical to
each other
Explain why the sperms produced by a male honeybee are genetically identical to
each other
Describe the function of centromere during the separation of chromosomes.
Describe the function of centromere during the separation of chromosomes.
Attaches chromatids to spindle in
cell division
haploid or diploid
haploid: one set of chromosomes (gametes)
diploid two sets (body cells)
Give two ways in which meiosis produces variation.
independent assortment;
crossing over;
Suggest one advantage of sexual reproduction being stimulated by worsening environmental conditions.
Suggest one advantage of sexual reproduction being stimulated by worsening environmental conditions.
resistant spores produced;
Explain how there came to be two copies of each allele of each gene at this stage of
meiosis.
Explain how there came to be two copies of each allele of each gene at this stage of
meiosis.
DNA (in each chromosome) has replicated,
(to give two chromatids);
(so) two copies of the gene/allele, one on each chromatid;
diploid number of chromosomes in the organism
what is happening at this stage of meiosis
diploid number of chromosomes in the organism
what is happening at this stage of meiosis
crossing over + exchange of genetic information;
what happens during the anaphase stage
separation of homologous chromosomes by spindle fibres
What term is used to describe the pair of homologous chromosomes shown in Figure 2? (crossing over occurs)
What term is used to describe the pair of homologous chromosomes shown in Figure 2?
bivalent
Give two processes, other than crossing over, which result in genetic variation.
Explain how each process contributes to genetic variation.
Process :
Explanation :
Process :
Explanation :
Give two processes, other than crossing over, which result in genetic variation.
Explain how each process contributes to genetic variation.
Process : mutation
Explanation : different allele formed
Process : random fusion of gametes
Explanation : new combination of alleles;
