Genetic crosses + heredity

Question 1

composition of chromosomes

Answer 1

protein and DNA

Question 2

what are somatic cells

Answer 2

all the cells of an organism have the same no of chromosomes

Question 3

gametes

Answer 3

haploid cells capable of fusion ie egg +sperm

Question 4

what is the one exception to somatic cells in the human body?

Answer 4

egg or sperm/ gametes

Question 5

what is a homologous chromosome

Answer 5

2 chromosomes that are similar size and have the same gene location

Question 6

where are homologous chromosomes found

Answer 6

diploid cells

Question 7

alleles

Answer 7

different forms of the same gene usually found in 2 forms: dominant and recessive

Question 8

dominant

Answer 8

capital letter, masks the expression of a recessive allele

Question 9

recessive

Answer 9

small letter, masked by a dominant allele

Question 10

locus

Answer 10

position of a gene on a chromosome

Question 11

genotype

Answer 11

genetic makeup of an organism

Question 12

phenotype

Answer 12

physical appearance of an organism

Question 13

progeny

Answer 13

offspring produced

Question 14

homozygous

Answer 14

the 2 alleles of a gene are identical

Question 15

heterozygous

Answer 15

the 2 alleles of a gene are different

Question 16

incomplete dominance

Answer 16

neither allele, recessice or dominant masks the expression of the other

Question 17

what is an autosome

Answer 17

a chromosome that controls features that are independent of whether the person is male or female

Question 18

which chromosomes are female

Answer 18

XX

Question 19

which chromosomes are male

Answer 19

XY

Question 20

what are the consequences of the sex chromosomes

Answer 20

males determine the sex of a child
male to female ratio is 1:1

Question 21

how many chromosomes are autosomes

Answer 21

22 pairs

Question 22

law of segregation

Answer 22

inherited characteristics are controlled by pairs of factors. these alleles segregate at gamete formation, with only 1 member from each pair being found in each gamete

Question 23

law of independent assortment

Answer 23

when gametes are formed either a pair of alleles is equally likely to combine with either of another pair of alleles

Question 24

monohybrid

Answer 24

studying a single trait or characteristic

Question 25

dihybrid

Answer 25

studying 2 traits or characteristics

Question 26

what effect does linkage have on variation

Answer 26

reduces variation as independant assortment cannot occur

Question 27

what is linkage

Answer 27

when several genes are located on one chromosome which effects the way the genes split up at gamete level

Question 28

what is sex linkage

Answer 28

genes located on the sex chromosmes

Question 29

examples of sex linked characteristics

Answer 29

colour blindness
haemophelia

Question 30

pedigree

Answer 30

a diagram showing the genetic history of a group of related individuals