mitosis

Question 1

describe binary fission in bacteria

Answer 1

1. replication of circular DNA
2. replication of plasmids
3. division of cytoplasm

Question 2

explain the arrangement of genetic material in prophase

Answer 2

chromosomes are becoming visible because still condensing

Question 3

name the fixed position occupied by a gene on a DNA molecule

Answer 3

locus

Question 4

when taking a sample to investigate mitosis why do they take the sample from the root tip

Answer 4

because that’s where mitosis occurs

Question 5

why do you press down firmly on the coverslip when taking a sample for a microscope

Answer 5

so there’s a thin layer of cells that light can pass through

Question 6

what is a homologous pair of chromosomes

Answer 6

two chromosomes that carry the same genes

Question 7

describe two aseptic techniques and their purposes

Answer 7

1. flame the neck of the culture container to maintain a pure culture
2. wear gloves to prevent contamination from bacteria on hands / mouth

Question 8

describe the appearance of behaviour of chromosomes during mitosis

Answer 8

prophase- chromosomes condense
metaphase- chromosomes attach to spindle fibres by their centromere and line up in centre
anaphase- centromere splits and chromosomes are pulled to opposite sides
telophase- chromatids uncoil

Question 9

what is the G1 phase

Answer 9

cell grows
mRNA and proteins are synthesised