BIO Y13 MOCK ESSENTIALS

Question 1

How does sexual reproduction lead to genetic variation in offspring

Answer 1

Independent assortment of bivalents in Metaphase I -> Homologous chromosones have wider range of allele combinations

Random fertilisation -> Meiosis produces genetically different cells

Crossing over of Chiasma in Prophase I -> Alleles swapped betwen Non-Sister Chromatids

Offpsring has alleles from more than 1 parent –> VARIETY OF ALLELES

Question 2

Why is zygote needed for mitosis

Answer 2

For growth which needs genetically identical cells

Question 3

How are new xylem cells produced

Answer 3

By cambium by differentiation

Question 4

what are 3 ways embroynic stem cells can be produced for research

Answer 4

-Toxicity for new drug
-Test how effective new medinal drugs are
-Tests how stem cells differentiate into different cell types

Question 5

How does organisation of Homolgous Chromosones during Metapahse I increase gentic variation

Answer 5

Genetically different chromatids
Homologous Chromosones line up along equator
Independent assortment
Homologous chromosones face opposite poles of the cell

Question 6

How are xylem vessel elemtns produced from stem cells

Answer 6

Cell elongation
Lingifcation of cell walls
By differentiation

Question 7

How does sexual reproduction produce genetically variation

Answer 7

Genetic Variation caused by variety of alleles hencer offspring has alleles from more than one parent
Crossing over of chiasma in Prophase I -> chromatids has new combination of alleles and alles swapped between non sister chromatids
Random fertilisation hence meiosis produces 2 new genetically different gametes
Sperm from hydra fertilies egg fro nay other hydra -> 2 hydra w/ diff alleles

Question 8

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