B16 inheritance Flashcards
1
Q
what are chromosomes made of
A
- DNA
- containing genetic information in the form of genes
2
Q
define gene
A
length of DNA that codes for a protein
3
Q
define allele
A
alternative form of a gene
4
Q
describe the inheritance of sex in humans
A
- 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
5
Q
describe what is meant by a haploid nucleus
A
contain single set of chrommosomes
6
Q
describe what is meant by a diploid nucleus
A
contain two sets of chromosomes
7
Q
chromosomes in diploid cell
A
- pair of each type of chromosome
- in human diploid cell, 23 pairs
8
Q
describe what is meant by mitosis
A
- nuclear division
- giving rise to genetically identical cells
9
Q
state the role of mitosis
A
- growth and repair of damaged tissues
- replacement of cells
- asexual reproduction
10
Q
process of mitosis
A
- exact replication of chromosomes
- copies of chromosomes separate
- chromosome number in each daughter cell maintained
11
Q
function of meiosis
A
involved in production of gametes
12
Q
describe what is meant by meiosis
A
- reduction division
- chromosome number halved from diploid to haploid
- results in genetically different cells
13
Q
where does meiosis occur
A
male testes and female ovaries
14
Q
describe what is meant by inheritance
A
- transmission of genetic information
- from generation to generation
15
Q
describe what is meant by genotype
A
- genetic make-up of an organism
- in terms of its alleles present
