Topic 1- genetics

Question 0

what is DNA

Answer 0

• acts as a blueprint for living things

- makes up the material in genes

Question 1

what are chromosomes?

Answer 1

• parts of the nucleus made up of genes and DNA

- exist in pairs

Question 2

what are genes?

Answer 2

• pieces of DNA

- controls a particular characteristic

Question 3

what is an allele?

Answer 3

-variations of genes

Question 4

what is the importance of genes?

Answer 4

• influence what we look like and how we work

- passes on genetic information that controls all aspects of our cells

Question 5

what is meiosis?

Answer 5

-cell division that occurs in reproductive organs

Question 6

what is the purpose of meiosis?

Answer 6

• ensures all organisms produced contain the correct number of chromosomes
• determines the sex of the child

Question 7

what is the difference between meiosis and mitosis?

Answer 7

meiosis produces daughter cells with half the number of chromosomes at the parent cell where as mitosis produces the same number

Question 8

what are your two sex chromosomes and what do they determine?

Answer 8

chromosome 23

-determine your sex

Question 9

what sex chromosome combination creates a:

a. female
b. male

Answer 9

female- XX

male- XY

Question 10

how are identical and fraternal twins formed?

Answer 10

Identical- one sperm and one egg, embryo splits into two bundles of cells, not genetic

fraternal- two eggs and two sperm, genetic

Question 11

what is a karyotype?

Answer 11

diagram of chromosomes

Question 12

what is a genotype?

Answer 12

different combinations of the parents gene

Question 13

what is homozygous and heterozygous?

Answer 13

homozygous- alleles are the same

heterozygous- alleles are different

Question 14

what is a phenotype?

Answer 14

appearance produced by the genotype

Question 15

what is codominance?

Answer 15

the phenotype of a heterozygous organism is a combination of the phenotypes of a homozygous organism

both traits are dominant therefore both phenotypes is equally expressed

Question 16

what is incomplete dominance?

Answer 16

a heterozygous offspring has a phenotype between the phenotypes of the parents

both characteristics are recessive

Question 17

what is sex linkage?

Answer 17

gender genes - chromosome 23

x can carry non gender genes but y can’t

Question 18

structure of DNA: what is DNA made up of?

Answer 18

nucleotides

Question 19

what is a nucleotide made up of

Answer 19

base
phosphate
base-ademine, thymine, guanine, cytosine