inheritance variation and evolution

Question 1

allele definition

Answer 1

a version of a gene

Question 2

DNA definition

Answer 2

The chemical that all of the genetic material in a cell is made up from.

Question 3

what the structure of DNA?

Answer 3

double helix

Question 4

chromosome definition

Answer 4

thin strands of DNA

Question 5

gene definition

Answer 5

a small section of DNA found on a chromosome

Question 6

genome definition

Answer 6

the entire genetic material of an organism

Question 7

nucleotide definition

Answer 7

consists of a sugar, a phosphate group and a base

Question 8

complementary base paring definition

Answer 8

A always pairs with T
C always pairs with G

Question 9

hormone definition

Answer 9

a protein that is used to carry messages around the body

Question 10

structural proteins

Answer 10

are physically strong e.g.,. collagen

Question 11

mutation

Answer 11

a random change in the genetic code of an organism over time

Question 12

sexual reproduction definition

Answer 12

where genetic material from two organisms is combined to produce offspring which are genetically different to either parent.

Question 13

asexual reproduction definition

Answer 13

there is only one parent so the offspring are genetically identical to that parent.

Question 14

advantages of sexual reproduction

Answer 14

.offspring have a mixture of two sets of chromosomes, which produces variation in the offspring
.variation increases the chance of a specie surviving a change in the environment.
.we can use selective breeding to speed up natural selection

Question 15

homozygous definition

Answer 15

if an organism has two alleles for a particular gene that are the same

Question 15

advantages of asexual reproduction

Answer 15

.there only needs to be one parent so uses less energy than sexual reproduction
.asexual reproduction is faster than sexual reproduction
.many identical offspring can be produced in favourable conditions

Question 16

heterozygous definition

Answer 16

if an organism has two alleles for a particular gene that are different

Question 17

dominant vs recessive genes

Answer 17

dominant= CC or Cc
recessive= and cc

Question 18

genotype definition

Answer 18

A genotype is the collection of genes an organism has.

Question 19

phenotype definition

Answer 19

the physical characteristics of an organism

Question 20

what is cystic fibrosis caused by?

Answer 20

a recessive allele

Question 21

what is polydactyly caused by?

Answer 21

a dominant allele

Question 22

gamete definition

Answer 22

a reproductive cell of an animal or plant

Question 23

variation definition

Answer 23

the differences that exist between individuals of a species

Question 24

evolution definition

Answer 24

The theory that all living organisms evolved from earlier less complex forms of life during the history of the earth

Question 25

selective breeding

Answer 25

when humans artificially select the characteristics of the plants and animals they are going to breed.

Question 26

advantages and disadvantages of selective breeding

Answer 26

advantages= .better quality of foods can be produced .crops will have higher resistance to disease disadvantages= .reduces the gene pool, so variation decreases .can cause health problems because greater chance of organisms inheriting harmful genetic defects when gene pool is limited.

Question 27

fossils definition

Answer 27

remains of organisms that have decayed many thousands of years ago

Question 28

speciation definition

Answer 28

the development of new species

Question 29

classification definition

Answer 29

is organising living organisms into groups based on their characteristics

Question 30

Classification order 1-7

Answer 30

1.kingdom 2.phylum 3.class 4.order 5.family 6.genus 7.species

Question 31

Archaea domain definition

Answer 31

they were thought to be primitive bacteria but they are a different type of prokaryotic cell. They were first found in extreme places such as hot springs and salt lakes.

Question 32

bacteria domain definition

Answer 32

contains true bacterial like coli and staphylococcus

Question 33

Eukaryota domain definition

Answer 33

includes broad range of organisms including fungi, plants, animals and protists

Question 34

how are organisms named?

Answer 34

they are named according to the binomial system