6.2-endless genetic crosses (inheritance)

Question 1

what do mutagens do?

Answer 1

increase rate of mutation

Question 2

when may chromosome mutations occur?

Answer 2

meiosis

Question 3

what are the types of chromosome mutation?

Answer 3

deletion
inversion
translocation
duplication
non-disjunction

Question 4

what happens to chromosomes during deletion?

Answer 4

part of a chromosome is lost (duh)

Question 5

what happens to chromosomes during inversion?

Answer 5

section of chromosome breaks off, turns 180 degrees, joins again

Question 6

why is inversion a problem even though all genes are still present?

Answer 6

some genes may be too far away from their regulatory sequences to be expressed.

Question 7

what happens to chromosomes during translocation?

Answer 7

piece of chromosome breaks off and becomes attached to another chromosome.

Question 8

what happens to chromosomes during duplication?

Answer 8

piece of chromosome mAy bE dUpLicAtEd.

Question 9

what happens to chromosomes during non-disjunction?

Answer 9

1 pair of chromosomes or chromatids fails to separate, leaving a gamete w an extra chromosome.

Question 10

what is a condition caused by non-disjunction?

Answer 10

downs syndrome-extra chromosome 21

Question 11

what is aneuploidy?

Answer 11

when the chromosome number isn’t an exact multiple of the haploid number for that organism.

Question 12

what is polyploidy?

Answer 12

when you have more than 2 sets of chromosomes.

Question 13

what’s the result of a diploid gamete and haploid gamete fusing?

Answer 13

triploid zygote

Question 14

what’s the result of 2 diploid gametes fusing?

Answer 14

tetraploid zygote

Question 15

during meiosis what may genetic variation result from?

Answer 15

allele shuffling-prophase 1

independent assortment: metaphase 1 and 2

Question 16

what are 2 examples of variations caused solely by the environment?

Answer 16

speaking dialect

scar

Question 17

what happens to chlorotic plants?

Answer 17

have genotype for making chlorophyll but environment preventing expression.

Question 18

what is another word for homozygous?

Answer 18

true-breeding

Question 19

what does monogenic mean?

Answer 19

determined by a single gene.

Question 20

what does dihybrid mean?

Answer 20

involving 2 gene loci.

Question 21

what is a gene locus?

Answer 21

a fixed position on a chromosome

Question 22

what is codominance?

Answer 22

where both alleles present in the genotype of a heterozygous individual contribute to the individual’s phenotype.

Question 23

what happens when a gene is said to have multiple alleles?

Answer 23

3 or more alleles at a particular gene locus are known.

Question 24

what are autosomes?

Answer 24

chromosomes that aren’t sex chromosomes

Question 25

the X and Y chromosomes are not fully…

Answer 25

homologous

Question 26

why does a small part of the X and Y match?

Answer 26

so they can pair of before meiosis

Question 27

what are examples of sex-linked characteristics in humans?

Answer 27

haemophilia A

colour blindness

Question 28

what are the symptoms of haemophilia A?

Answer 28

can’t clot blood fast enough-injuries may cause bleeding or internal haemorrhage

Question 29

in every female cell nucleus how many X chromosomes are active?

Answer 29

only 1-the other one in inactivated so females don’t have double the no of X-linked genes being expressed as males.

Question 30

what happens during autosomal linkage?

Answer 30

gene loci present on the same autosome are often inherited together.