MYTUTOR SUBJECT ANSWERS

442 views

Why are organisms within a species genetically different?

1) Crossing over - in Prophase I of meiosis, non-sister chromatids in the same bivalent (i.e. chromatids on separate chromosomes within a homologous pair) can exchange alleles, creating new combinations.

2) Independent assortment - the random alignment of chromosomes in Metaphase I, and of chromatids in Metaphase II, means that random combinations of maternal and paternal DNA are brought together.  For example, the maternal chromosome from pair A may be combined with the paternal chromosome from pair B.  This process alone can produce 2n genetically unique gametes, where n is the haploid number.

3) Fertilisation - any sperm cell could fertilise a given egg cell, increasing the number of possible combinations of genetic material.

4) Mutation - random DNA mutations may occur during DNA replication (part of interphase).  If the mutations are in the gametes, they will be passed on to offspring.

Katherine F. A Level Chemistry tutor, A Level Biology tutor, GCSE Fre...

1 year ago

Answered by Katherine, an A Level Biology tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

168 SUBJECT SPECIALISTS

£20 /hr

Daniel M.

Degree: Evolutionary and Behavioural Ecology (Masters) - Exeter University

Subjects offered:Biology, Zoology+ 1 more

Biology
Zoology
-Personal Statements-

“MSc graduate and soon-to-be doctoral student tutoring biology at both GCSE and A Level.”

MyTutor guarantee

£22 /hr

Shreya G.

Degree: Biochemistry with molecular medicine (Bachelors) - Nottingham University

Subjects offered:Biology, Maths+ 1 more

Biology
Maths
-Personal Statements-

“I am a first year undergraduate student at The University Of Nottingham, currently studying Biochemistry with molecular medicine. ”

£24 /hr

Jessica-Lily H.

Degree: MRes Experimental Neuroscience (Masters) - Imperial College London University

Subjects offered:Biology, Psychology

Biology
Psychology

“Top tutor from a world leading university- ready to do all I can to help you get your head around that tricky subject!”

About the author

Katherine F.

Currently unavailable: for new students

Degree: Biochemistry (Bachelors) - Oxford, Trinity College University

Subjects offered:Biology, German+ 2 more

Biology
German
French
Chemistry

“Hi!  I'm a first-year biochemist at Oxford University and I am very keen to help with biology and chemistry A levels, or with French and German at GCSE.  I love learning and want to pass on this enthusiasm, as well as helping students ...”

MyTutor guarantee

You may also like...

Posts by Katherine

What evidence is there to support the delocalised model of benzene over Kekulé's model?

How can an aldehyde be distinguished from a ketone?

How do auxins bring about positive phototropism in plants?

How do ionic charge and radius affect lattice enthalpy?

Other A Level Biology questions

What is alternative splicing

What is respiration and why is it needed?

What is the Electron Transport Chain (ETC) and how does it help make ATP in cellular respiration?

State three factors which effect enzyme activity. (3)

View A Level Biology tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok