paper 2 bio

Question 1

capacitation

Answer 1

changes in the sperms membranes that increases the fulidity and allows the acrosome reaction to occur

Question 2

trophoblast

Answer 2

cell forming the outer layer of the blastocyst

Question 3

implantation

Answer 3

the embedding of the blastocyst into the endometrium

Question 4

dehisence

Answer 4

the opening of the anther, releasing pollen

Question 5

protandry

Answer 5

staments ripen before the stigma

Question 6

germination

Answer 6

the biochemical and physiological processes through which a seed becomes a photosynthesising plant

Question 7

gene

Answer 7

a sequence of DNA occupying a specific locus on a chromosome, normally coding for a specific polypeptide

Question 8

allele

Answer 8

a different form of the same gene, coding for a specific polypeptide

Question 9

homozygous

Answer 9

when both alleles are given charactersistic are the same

Question 10

heterozygous

Answer 10

where both alleles for a given charecteristic are different

Question 11

epigenetics

Answer 11

the control of the genes expression by modifying the DNA or histones without the modification of a base sequence

Question 12

selection pressure

Answer 12

an enviromental factor which can alter the frequency of alleles in a population, when its limiting

Question 13

natural selection

Answer 13

the increases chance of survival and reproduction of an organism with phenotypes suited to their enviroment, enhancing the transfer of faverouble alleles from one generation to the next

Question 14

gene pool

Answer 14

all the alleles present in a population at a given time

Question 15

allele frequency

Answer 15

the frequency of an allele in its proportion, fraction or percentage of all alleles of that gene in a gene pool

Question 16

genetic drift

Answer 16

chance variation of allele frequencies in a population

Question 17

founders affect

Answer 17

the loss of genetic variation in a new population established by a very small number of individuals from a larger population

Question 18

species

Answer 18

a group of individuals with similar charateristics which can interbreed to produce fertile offspring

Question 19

allopatrics speciation

Answer 19

evolution of a new species from demes isolatied in different geographical locations

Question 20

sympatrics speciation

Answer 20

the evolution of a new species from demes sharing the same geographical location

Question 21

transgenic

Answer 21

an organism that has been genetically modified by the addition of a gene or genes from another species