B16 inheritance

Question 1

what are chromosomes made of

Answer 1

• DNA
• containing genetic information in the form of genes

Question 2

define gene

Answer 2

length of DNA that codes for a protein

Question 3

define allele

Answer 3

alternative form of a gene

Question 4

describe the inheritance of sex in humans

Answer 4

• sperm cell contains one X OR Y chromosome
• egg cell contains one X chromosome
• sex of child depends on sperm. if Y male, if X female

males have one X chromosome and one Y chromosome, XY

females have two X chromosomes, XX

Question 5

describe what is meant by a haploid nucleus

Answer 5

contain single set of chrommosomes

Question 6

describe what is meant by a diploid nucleus

Answer 6

contain two sets of chromosomes

Question 7

chromosomes in diploid cell

Answer 7

• pair of each type of chromosome
• in human diploid cell, 23 pairs

Question 8

describe what is meant by mitosis

Answer 8

• nuclear division
• giving rise to genetically identical cells

Question 9

state the role of mitosis

Answer 9

• growth and repair of damaged tissues
• replacement of cells
• asexual reproduction

Question 10

process of mitosis

Answer 10

• exact replication of chromosomes
• copies of chromosomes separate
• chromosome number in each daughter cell maintained

Question 11

function of meiosis

Answer 11

involved in production of gametes

Question 12

describe what is meant by meiosis

Answer 12

• reduction division
• chromosome number halved from diploid to haploid
• results in genetically different cells

Question 13

where does meiosis occur

Answer 13

male testes and female ovaries

Question 14

describe what is meant by inheritance

Answer 14

• transmission of genetic information
• from generation to generation

Question 15

describe what is meant by genotype

Answer 15

• genetic make-up of an organism
• in terms of its alleles present

Question 16

describe what is meant by homozygous

Answer 16

have 2 identical alleles of a particular gene

Question 17

define pure-breeding

Answer 17

2 identical homozygous individuals that breed together

Question 18

describe what is meant by heterozygous

Answer 18

have 2 diff alleles of particular gene

Question 19

will heterozugous individual be pure-breeding?

Answer 19

no

Question 20

describe what is meant by a dominant allele

Answer 20

allele that is expressed if it is present in the genotype

Question 21

describe what is meant by a recessive allele

Answer 21

allele that is only expressed when there is no dominant allele of the gene present in the genotype

Question 22

how to represent dominant allele

Answer 22

capital letter

Question 23

how to represent recessive allele

Answer 23

lowercase letter

Question 24

what is a monohybrid cross

Answer 24

• breeding of 2 individuals
• that differ in their alleles for a particular gene

Question 25

what does a square represent in a pedigree diagram

Answer 25

male

Question 26

what does a circle represent in a pedigree diagram

Answer 26

female

Question 27

how are individuals who show inherited characteristics represented in pedigree diagram

Answer 27

coloured symbol

Question 28

how are individuals who do not show inherited characteristic shown

Answer 28

white symbol

Question 29

define carrier

Answer 29

individual who carries one copy of a recessive allele for a genetic characteristic

Question 30

how is a carrier shown on a pedigree diagram

Answer 30

partly shaded symbol