B6 Genetic Diagrams (page 72)

Question 1

Some Characteristics are controlled by what?

Answer 1

Single Genes.

Question 2

Depending what genes you interit controls what?

Answer 2

controls the characteristics you develop.

Question 3

Different genes control different characteristics. Some characteristics are controlled by a single gene, give an example in animals and humans?

Answer 3

e.g Mouse fur colour and
red-green colour blindness in humans.

Question 4

even though some characteristics are controlled by a single gene, most characteristics are controlled by what?

Answer 4

controlled by several genes interacting.

Question 5

All Genes exist in different versions called what?

Answer 5

Alleles
(which are represented by letters in Genetic Diagrams).

Question 6

How many versions of Alleles of every Gene is in your body?

Answer 6

You have two versions (Alleles) of every gene in your body - One on each chromosome in a pair.

Question 7

If an Organism has Two Alleles for a particular Gene that are the SAME, what is it called?

Answer 7

It is Homozygous for that trait.

Question 8

If an Organism has Two Alleles for a particular gene, are DIFFERENT, what is this called?

Answer 8

Its Heterozygous

Question 9

If the two Alleles are different, only oNE can determine what characteristic is present, explain why?

Answer 9

The Allele for the characteristic that’s shown is called the dominant Allele

(dominant means having a power or influence over the others).

Question 10

When you do a Genetic Diagram, how do you use the letters that control the characteristics for a Dominant Allele?

Answer 10

You use a capital letter for dominant alleles - e.g. ‘C’).

Question 11

When you do a Genetic Diagram, how do you use the letters that control the characteristics for a Recessive?

(Recessive means tending to recede/withdrawn/producing little or no effect)

Answer 11

You show these with small letters - (e.g. c)

Question 12

For an organism to display a recessive characteristic, give an example of what you would use on a genetic diagram to show this?

Answer 12

Both its Alleles must be recessive (e.g. cc)

Question 13

For an organism to display a Dominant characteristic the organism can be what? on a genetic diagram display?

Answer 13

The organism can be either CC or Cc, because the dominant allele overrules the recessive one if the plant/animal/other organism is Heterozygous.

Question 14

Your Genotype is the conbination of what?

Answer 14

a conbination of alleles you have.

Question 15

Your Alleles work at a Molecular level to determine what characteristics you have, what is this called?

Answer 15

Your Phenotype.

Question 16

What do Genetic Diagrams show?

Answer 16

the possible Alleles of Offspring

Question 17

Suppose you start breeding hamsters with superpowers. The Allele which causes hampsters to have superpowers is recessive (b), whilst normal (boring) behaviour is due to a dominant allele (B).

What genotype must the superpowered hamster and the normal hamster have?

Answer 17

The superpowered hamster must have the genotype bb.

The normal hamster could be BB or Bb

(genotype = BB or Bb, phenotype = normal)

Please look at page 72 diagram of what happens if you breed from two homozygour hamsters. (important you understand the diagram, as you need to be able to produce and interpret both of these types of genetic diagrams for the exam).

Question 18

Define genotype and phenotype? (2 marks)

Answer 18

Your Genotype is the combination of alleles you have (1 mark)

Your Phenotype is the characteristics you have (1 mark)